# Gaggia Classic - Portafilter Pressure Gauge - OPV mod



## tribs

I got around to making a pressure gauge for my Classic.

I was looking for the parts to make it and found an ebay seller that had everything I needed - cpmpneumatics. It turned out the seller was only a couple of miles away so I called in and picked them up.

Anyway I thought I'd post the details so anyone can order them and make their own. The only extra you'll need is some PTFE tape to seal the threads. I only needed it on the portafilter.

Please note: This assumes your PF thread is 3/8" BSP

Pressure Gauge

Reducing Bush

If you need PTFE tape they even do that

PTFE Tape

Here is the finished article.


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## Rob505

Thanks so much for this. Saved me the embarrassment of having to explain to the local plumbers merchant what I am trying to do.


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## russe11

Thats great.. just what I have been after! Best bit is the price!

Many thanks!


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## MikeHag

Just a thought... have you considered adding a ball valve to the setup, which would allow you to let water flow out at a rate simulating an espresso shot?


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## matt-

What is the optimum recommended pressure?


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## tribs

MikeHag said:


> Just a thought... have you considered adding a ball valve to the setup, which would allow you to let water flow out at a rate simulating an espresso shot?


I have thought about this quite a bit and have done a bit of digging on the interweb. I was trying to get to the source of the 10bar static pressure = 9 bar brew pressure myth.

A ball valve apparently is not the best option as it is difficult to control flow, but needle valves are a little pricey. Some have suggested open the steam valve which is something I am going to try. Others say it is almost impossible to replicate the espresso shot in any case and it is best to experiment with various static readings and choose which tastes best.


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## tribs

I have tried the steam valve method and there is no more than 0.4 bar difference (disclaimer: on my machine). I cracked a leak on the portafilter gauge itself at about the same flow rate, just to check it mattered where the pressure relief was located, but it made near as darn no difference.

I adjusted down to just below 9 bar. First shot was a choker so dialled the grind a bit coarser. Second shot definitely was about right (40g from 18g in 25secs) and there was no doubt a LOT more crema, but it looks and tastes a little over extracted. Still good, but certainly leaning that way. I have found that pressure does have quite an effect on temp surfing, so will have a play and make sure I'm not runing too hot.


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## carbonkid85

This is great - will also be ordering!

Now any suggestions on how best to remove the PF spout without a vice? Haven't tried it, but I imagine it's stuck pretty tight...


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## tribs

He he. That is by far the hardest part of the exercise. It has some loctite on it or similar.

I don't have a vice. I found a screwdriver that fit through the spout. I felt sure I was going to snap it on a number of occasions.

It was not a case of cracking the glue and wind it off either. It took several turns before it got any easier and several times I feared it was stuck solid, I couldn't even wind it back. Anyway perseverance go me there in the end.

It would be a lot easier with a vice


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## carbonkid85

Hmmmm. My poky East London flat doesn't allow for a workshop unfortunately. Maybe I'll invest a few quid in one of those mini table vices...


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## Pedro083

Just go for the screwdriver and brute force and ignorance

Worked for me


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## nobrob

A screwdriver will damage the surface of your spout!

Take a hammer and a piece of wood. Lay the wood on one side of the spout and tap with the hammer.

It will budge


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## Pedro083

nobrob said:


> A screwdriver will damage the surface of your spout!
> 
> Take a hammer and a piece of wood. Lay the wood on one side of the spout and tap with the hammer.
> 
> It will budge


Lol I hate to think what you thought I meant to do with the screwdriver. You pass it through the hole in the spout it should be a nice tight fit thus giving you good purchase to unscrew the spouts no chance of damaging the surface or squashing the spouts


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## RobD

Quick thing, if its locktite or something like it, one thing that may make it a bit soft & easier to undo would be Acetone (nail polish remover) as it dissolves some of the adhesive, It works on superglue to.


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## carbonkid85

Oh my poor suffering Classic. Hammers, acetone, screwdrivers, lumps of wood...

I had to use an extending wheel nut wrench to get inside the OPV!


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## carbonkid85

Oooh definitely a +1 for the company recommended for parts. I ordered yesterday afternoon and have just received my gauge at work!


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## carbonkid85

Just did the mod. Improvised by putting the round handle of a can opener through the spout and bashing it with a hammer until the loctite came off.

My Classic was running at TWELVE BAR. Got it down to just over 9 in two attempts.

Thanks everyone for your help. This is a great forum!


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## mrh

Tribs

Thanks for the links my gauge arrived today and i have just done the mod. My classic went off the gauge so above 13bar adjusted now to 10bar what a difference it makes

MRH


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## lookseehear

I've ordered the parts for one - thought it would be nice to have one less thing to think about!

Edit: I also wanted to know whether it's possible to preinfuse by opening the steam valve so I'm going to see what effect that has on the brew pressure too.


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## lookseehear

So my gauge parts arrived today - turns out my opv valve was set at 14 bar! I had guessed it might be a bit high as I'd been having quite a lot of channelling and had to grind really fine to slow the flow down.

I really think anyone with a classic that isn't using pods should do this mod.

Also, opening the valve on the steam wand does work for pre infusion - with the gauge attached and pump running you can effectively pressure profile with a bit of a twist of the steam knob. Not something I'm that bothered about at the moment but interesting none the less.


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## Jason1wood

Great thread, might have to have a go at this.

How do you adjust the pressure?


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## lookseehear

There's a guide in the technical / faults / how to section of the forum. It was quite easy although mine was a bit stubborn at first.


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## lookseehear

Now I have done the mod I'm happy to lend my gauge around to forum members. I'd like it back at some point but if anyone is interested then post up.

I know they're pretty cheap but once the adjustment is done its just going to be sat on my shelf. If the demand is anything like last time a gauge was sent around then we can come up with a system. Otherwise just £2 via PayPal to cover postage is fine with me. I'd rather it isn't just totally random people from the internets so I'll put an arbitrary limit of 10 genuine posts to be able to borrow.

List:

1. Jason1wood - done

2. Obsy - has gauge

3. Oldman

4. MartinB


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## Jason1wood

I'd like to borrow it mate. Just PM me how to send payment. Many thanks.


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## Obsy

Fab idea - I'd appreciate being added to the list.


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## lookseehear

I've started a list and pmd Jason. If you let me know when it has been passed on that would be good so I know where it currently is.


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## oldman

Please add me next on the list


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## Jason1wood

Received the gauge and tried it but water leaking everywhere and just showing 4 bar on the dial, I'll tighten everything up and give it another go.


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## lookseehear

Remember not to use a portafilter basket or the water will leak out between the basket and the portafilter. You shouldn't have to tighten it too much to get a seal.

Oh and I don't know of you noticed but I included a strip of Teflon tape for if it wasn't fitting the portafilter too neatly.


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## Jason1wood

Ah that's where I was going wrong, using the basket. Haha

Cheers for the info.


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## steve206

Received my parts today. All put togehter nice and easy, now the reading! My reading dial is vibrating quickly between 10-12 bar. So quick i dont know the true reading. I will adjust down and see how it settles.


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## lookseehear

I think mine was vibrating between 9 and 9.5 ish after adjustment. Don't worry about getting it spot on 9 though.


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## Pedro083

I would be putting it higher than 9 as that is the static pressure and not what you will get when pouring a shot. Think the conceived wisdom is a static reading of 10 will give you 9 bar while pouring a shot

Also I found it easier to get a reading if you fill the pressure gauge and portafilter up with water before attaching and release and re-attach it before retesting this stopped my needle moving as much. Less trapped air I suppose


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## Jason1wood

I done mine with the tips from Pedro, 10 bar pressure and pre filled gauge, my pressure was off the scale, had to give it 3 full turns of the Allen bolt to get to 10 bar pressure.

It's made a good bit of difference.

I can't believe the manufacturers don't have a set pressure before leaving the factory. If it wasn't for this site I would be non the wiser.

Id like to thank lookseehear for his generosity in forwarding his meter.

Could the next in line PM his address and I'll sent on.

Cracking job!


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## Obsy

Hi Jason, I've PM'd you my address - looking forward to seeing how high mine is. Think I'm going to hedge my bets and aim for 9.5!

Cheers, Emma


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## Jason1wood

Haha oops, I said his! Obviously I meant hers!!!

Just down the road in Stockton. I'm Newcastle, there seems to be a few of us Northerners on here.


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## Obsy

I'll forgive you, being a fellow Northerner! There is a few of us on here, should maybe meet up to geek out on coffee!


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## Jason1wood

Geordie-barista should be on the list, he defo knows his stuff.


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## Obsy

Oh he is don't worry! He's hopefully going to show me the numerous errors of my feeble attempts at coffee making!


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## Jason1wood

Ah you hiring his services at £20p/h?

I was thinking about doing the same but not until I get a grinder, all my funds are tied up for my new apartment.


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## Obsy

To be honest, he offered before advertising the £20p/h so I'm not sure.

Good luck with the new apartment - will it be a typical batchelor pad? No doubt the gaggia will take pride of place in the kitchen!


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## steve206

Is the consensus then that the pressure should be at 10bar using this gauge? Done mine, took a fair few turns, just waiting for me beens to turn up to give it a real test!


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## Jason1wood

I set mine at 10 bar. I think I had to do 3/4 full turns with the allen key, was really that high. Haha

Emma thanks, but a little old for a bachelor pad, I'm now middle aged (40) :-(

It's a converted church in Blaydon/Winlaton.


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## Obsy

I'm hoping my muscles are in better shape than I think or that my brother is free to help me out so I don't hold up the list. Did you check it after each full turn?

I meant batchelor pad as in gadgets and techy stuff so you're never too old, and 40 is nothing to frown about! Surely you won't have chintzy floral upholstry everywhere? Oh wow, I love places like that, am sure it'll be worth the wait.


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## Jason1wood

I did check it after every turn, just screw the bolt back, finger tight and replace the tube, no need to place the top lid on, just switch on and check pressure, repeat until its sorted.

I am a typical bloke, tech toys all over. Boys and their toys. Haha


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## Obsy

Ok, hopefully I'll be able to figure it out. Stand by guys for panicky messages when I attempt the mod.


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## steve206

An earth is connected to the top lid you take off, make sure you reconect it when your testing. No need to screw the lid back on though till your done.


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## Jason1wood

I didn't even bother putting the lid on when testing, just keep fingers out of the machine when turned on.


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## Obsy

Aye steve, I know about the earth as I've already been inside to replace the steam valve and look at the internals as I'm thinking of PID'ing it. My hands will be as far away from the internals when testing I can assure you!


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## sallycoffee

Just a quick ? I have a cubika and am a complete newbie and accidently filled up the portafilter without putting the basket in and blocked up the plastic valve bit at the bottom I have cleaned out with a small electrical screwdiver and now the coffee flows too fast - have I messed up the porta filter?


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## Rob505

I finally got around the ordering the parts from ebay - cant fault delivery and price.

I approached it with trepidation. The reports of using a tyre lever, a lump of wood and a hammer did not sound like fun. Anyway, all these concerns were unfounded. Although it took a bit of effort, a screwdriver through the hole in the portafilter worked well to remove the spout. Once the seal was broken it came away easily. Internally the bolt came away easily also even with my cheap socket set. I actually thought that it has slipped off the bolt. I didnt try the pressure first but turned the allen key through 270 degrees, checked the pressure and it was running at 9.5. Took it back to 180 degrees and it was bang on 10.

Once everything was put back together pulled a test shot. Im not going to try to describe the difference but it was much nicer than before with LOADS of crema.

Thanks to everyone for their posts that made this easy. Although it seems there is quite a few of these doing the rounds at the moment if anyone wants a borrow please let me know


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## MartinB

Would there be anyway I could be added to the list/borrow someones pressure gauge please?

Feel free to PM me!

Martin


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## lookseehear

Mine is floating around somewhere - Obsy might have it at the moment. Oldman is next after Obsy, but I've added you to the list after Oldman.


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## Rob505

I'm not around next week but if you havent managed to source one by the following weekend (4th August) your welcome to mine. PM me nearer the time and I'll get it in the post on the monday.


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## Jez W

Just to say thanks for all the information on this post and the ebay links - I have just ordered the parts myself off ebay so I will let you know how I get on in a weeks time.


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## MartinB

Rob505 said:


> I'm not around next week but if you havent managed to source one by the following weekend (4th August) your welcome to mine. PM me nearer the time and I'll get it in the post on the monday.


Awesome, thanks for that. forgot to say, i'm more than willing to pay postage both ways too.

Martin


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## Jez W

I've just had a fun hour taking my Gaggia apart and adjusting the OPV value. First reading was just under 12 bar, a 270 turn reduced this to ~10 bar. Just one question - should I expect the needle on the Pressure guage to be static, mine was vibrating around +-0.4bar?


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## Pablo

Thanks for the post tribs









I've ordered the bits from ebay and will be doing the OPV mod when they arrive.

Now I can see from the thread how to fit this equipment but how do I use it to do the mod?


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## Rob505

Pablo said:


> Thanks for the post tribs
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I've ordered the bits from ebay and will be doing the OPV mod when they arrive.
> 
> Now I can see from the thread how to fit this equipment but how do I use it to do the mod?


See this link

http://coffeeforums.co.uk/showthread.php?3859-Adjusting-the-OPV-(over-Pressure-Valve)-Gaggia-Classic


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## Pablo

Thank you Rob


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## Obsy

lookseehear said:


> Mine is floating around somewhere - Obsy might have it at the moment. Oldman is next after Obsy, but I've added you to the list after Oldman.


I do indeed have it Luke. I've send Oldman a message asking for his address to send it on but have had no response. Do you want me to send it to MartinB instead?


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## lookseehear

Fine by me, maybe oldman could have it afterwards.


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## MartinB

That would be great although I've just removed the spout from a spare portafilter I have so I may well have a crack at making one myself.


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## gwapenut

I see the yahoo groups talk about the need for fluid-filled pressure gauges (to stop the needle bouncing around) and needle valves to purge air from the system. Are these really necessary, or are people happy wit the kit from cpmpneumatics?


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## tribs

Not necessary IMO. I don't think you need to be that accurate.


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## gwapenut

I too can recommend the ebay seller cpmpneumatics on the first page of this thread. They helpfully combined postage and had the item with me in a day or so, normal royal mail through the letterbox, so no need to wait in for couriers.

So ... I've read pages and pages of threads, and am still unclear. Is there a general consensus on what the best static pressure to adjust for using this is, given static-dynamic differentials quoted of anything from 0.5 to 2? My gut instinct from a few posts is that it may be nearer 0.5, and so I am thinking of adjusting it so my new gauge reads 9.5.


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## MartinB

I paid for the items on Sunday, marked as dispatched on Monday and now it's Thursday they still haven't arrived!


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## Pablo

MartinB said:


> I paid for the items on Sunday, marked as dispatched on Monday and now it's Thursday they still haven't arrived!


I don't think the seller would have marked your items as dispatched if he hasn't sent them already. Where I live RM 1st class deliveries sometimes take three or four a few days to arrive. Hope you get yours soon though


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## gwapenut

Some feedback on blind filters.

Previously I adjusted it using the blind filter to give 125 ml in 30 seconds. I still felt the pressure was a little high, and eventually ordered the pressure gauge.

The static reading for 125/30 turned out to be 10.5-11 bar, so I have now adjusted it yet more downwards to 9.5 bar. The pressure gauge was well worth ordering, the blind filter/flow method simply did not get me far enough.

Had I more confidence in my tamping, grinding and choice of coffee beans, I could have experimented some more without resorting to the pressure gauge. But I felt there were too many unknowns, and am happy now that I have ruled out pressure from the list of things wrong.


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## MartinB

Pablo said:


> I don't think the seller would have marked your items as dispatched if he hasn't sent them already. Where I live RM 1st class deliveries sometimes take three or four a few days to arrive. Hope you get yours soon though


The package was delivered by MyHermes which explains a hell of a lot! Looking at the tracking history the item was marked lost at some point too!

Got the items yesterday, I wholly recommend the PTFE tape which sealed up the portafilter spout perfectly after my first attempt without.

Pressure from the OPV was off the scale when I first gave it a try, two more adjustments of the OPV and it was sat at 10 bar.

More crema, and a different note from the pump are the first two notable differences. Before the OPV mod, the pump used to go almost silent after a few seconds and then as soon as the coffee would pour the pump would change tone again. Now the pump noise is consistent throughout the shot.

Definitely going to drink more espresso now, I prefer flat whites but it's time consuming in the morning to make and then let cool down. Now the pressure is calibrated it's definitely high time to taste my extractions.


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## Milesy

Pedro083 said:


> Just go for the screwdriver and brute force and ignorance
> 
> Worked for me


I also done this. I smashed the spouts to pieces using the brute force method but I don't use this portafilter anyway so I am happy keeping it for pressure checking only.


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## Milesy

and I used a hammer as well


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## MartinB

Same here! A mild tap of the hammer and it was loosened which was good.


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## gwapenut

I used an adjustable wrench which wrapped around the spouts nicely. Came off relatively easily, wrench in one hand, portafilter handle in the other (PF held near the metal bit to avoid stressing it too much)


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## omega

Hi All

I have just got the bits for the pressure test and have the following question.

I primed the guage and i got the following reading 14+ bar then droped down to 12 bar which was steady what is my bar reading the 14+ or 12 bar ?

Regards Steve


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## MartinB

If it was consistently 12 then i'd go with the 12.


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## aaroncornish

Apologies for the holy thread revival, but I aim ordering my parts for this and had a question.

You mention that the portafilter thread is 3/8 BSP, dumb question but how I can I check this?

I have seen another post that says to use a 1/4 thread.... agghh

I might just order both to be on the safe side









Thanks

Aaron



tribs said:


> I got around to making a pressure gauge for my Classic.
> 
> I was looking for the parts to make it and found an ebay seller that had everything I needed - cpmpneumatics. It turned out the seller was only a couple of miles away so I called in and picked them up.
> 
> Anyway I thought I'd post the details so anyone can order them and make their own. The only extra you'll need is some PTFE tape to seal the threads. I only needed it on the portafilter.
> 
> Please note: This assumes your PF thread is 3/8" BSP
> 
> Pressure Gauge
> 
> Reducing Bush
> 
> If you need PTFE tape they even do that
> 
> PTFE Tape
> 
> Here is the finished article.


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## seeq

aaroncornish said:


> Apologies for the holy thread revival, but I aim ordering my parts for this and had a question.
> 
> You mention that the portafilter thread is 3/8 BSP, dumb question but how I can I check this?
> 
> I have seen another post that says to use a 1/4 thread.... agghh
> 
> I might just order both to be on the safe side
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Thanks
> 
> Aaron


The gaggia PF is 3/8 BSP, most gauges are 1/4 BSP, so you will need an adaptor such as this --> http://www.ebay.co.uk/itm/3-8-X-1-4-BSPT-HEX-REDUCING-BUSH-316-STAINLESS-STEEL-/220594588050?pt=UK_DIY_Materials_Plumbing_MJ&hash=item335c764992 just check your gauge is 1/4 BSP first


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## aaroncornish

seeq said:


> The gaggia PF is 3/8 BSP, most gauges are 1/4 BSP, so you will need an adaptor such as this --> http://www.ebay.co.uk/itm/3-8-X-1-4-BSPT-HEX-REDUCING-BUSH-316-STAINLESS-STEEL-/220594588050?pt=UK_DIY_Materials_Plumbing_MJ&hash=item335c764992 just check your gauge is 1/4 BSP first


Thanks for this. I had ordered the 3/8 thankfully.

Time for another dumb question... Is it counter clockwise, assuming I have it upside down and the handle pointing towards me? Don't want to spend hours trying to turn it the wrong way and make it tighter

Aaron


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## seeq

I befall confused when you turn things around and upside Down! It turns the same as a standard screw/bolt


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## Dave.wilton

aaroncornish said:


> Thanks for this. I had ordered the 3/8 thankfully.
> 
> Time for another dumb question... Is it counter clockwise, assuming I have it upside down and the handle pointing towards me? Don't want to spend hours trying to turn it the wrong way and make it tighter
> 
> Aaron


Turn anti clockwise whichever way you have it up. I just did mine and it was really hard work. I got it off without destroying it, but left quite a few teeth marks from the adjustable pliers I used. You could still use it, but if I decide to sell the machine it might need replacing (I don't use it). A screw driver didn't work for me, what the hell is that glue! I ended up wedging the spout it in to something heavy (a big old radiator!) and turned (anti clocckwise!), that did the trick.

Just waiting for my gauge to turn up, hopefully tomorrow.


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## seeq

If you struggle to get the spout off. Use an old cloth to protect it, stick the PF in a vice, use another cloth to protect the spout and give it a good wrench with some grippers. It will come off with brute force


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## reneb

or try putting a screwdriver through the spout - should give you the leverage you need without leaving any marks


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## MartinB

^^ That worked for me.


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## Steve_S_T

lookseehear said:


> Now I have done the mod I'm happy to lend my gauge around to forum members. I'd like it back at some point but if anyone is interested then post up.
> 
> I know they're pretty cheap but once the adjustment is done its just going to be sat on my shelf. If the demand is anything like last time a gauge was sent around then we can come up with a system. Otherwise just £2 via PayPal to cover postage is fine with me. I'd rather it isn't just totally random people from the internets so I'll put an arbitrary limit of 10 genuine posts to be able to borrow.
> 
> List:
> 
> 1. Jason1wood - done
> 
> 2. Obsy - has gauge
> 
> 3. Oldman
> 
> 4. MartinB


If this is still available I'd be very grateful to borrow it to check the pressure on my Classic. Please feel free to message me if you're stool happy to lend it out.

Thanks,

Steve.

Sent from my Nexus 7 using Tapatalk HD


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## lookseehear

Steve_S_T said:


> If this is still available I'd be very grateful to borrow it to check the pressure on my Classic. Please feel free to message me if you're stool happy to lend it out.
> 
> Thanks,
> 
> Steve.
> 
> Sent from my Nexus 7 using Tapatalk HD


Fine by me, I think it's still with Obsy as MartinB made his own one. Maybe send Obsy a pm and she can arrange delivery.


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## Steve_S_T

lookseehear said:


> Fine by me, I think it's still with Obsy as MartinB made his own one. Maybe send Obsy a pm and she can arrange delivery.


I've done that, many thanks.

Steve.


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## Dave.wilton

Just finished reducing the pressure on mine. Had to take my rocky grind down a bit. First shot 26g in 26seconds from 15g beans. Bang on the money! Tasted fantastic!

There wast too much wobble from the dial in the end. Mine wasn't as high as others have reported, about 12 bar


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## Steve_S_T

Hmmm, no reply to my PM from Obsy and I notice from her profile that it's been a while since she posted on the forums. Any further thoughts? Perhaps I'll PM Martin B to see whether he did receive it as per post 61.


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## dimitris

Hi guyz i would like to enter the chain..... I just bought a classic and i want to start doing some mods..

Nice to find a very good forum like this one!!


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## mym

See also this thread: http://coffeeforums.co.uk/showthread.php?3859-Adjusting-the-OPV-(over-Pressure-Valve)-Gaggia-Classic/page20


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## GS11

Great to see people lending these out to other forum members.

Thanks to the op for listing the parts to make the gauge.

Now ordered...thanks.


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## frustin

Ive got the OPV mod equipment turning up next week. Did you all have to alter your grind coarseness again after making the adaptation. I'm assuming that it must have less pressure and therefore more difficult for the water to pass through the puck?

Thanks

Justin


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## frustin

mine is now 10bar. not really seeing a lot of difference, i did have to grind less coarse though. Removed some of the bitterness i felt.


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## sup3rdup3r

Steve_S_T said:


> Hmmm, no reply to my PM from Obsy and I notice from her profile that it's been a while since she posted on the forums. Any further thoughts? Perhaps I'll PM Martin B to see whether he did receive it as per post 61.


Any luck with getting this posted out? If there is the opportunity to borrow this next please let me know.

Thanks

Olly


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## autopilot

Is there any chance of borrowing a gauge from some kind soul? Or getting added to the list? I have read elsewhere that some Classics are shipping as high as 16bar these days.

If not, i see there is a couple on ebay for £30. Anyone up for a group purchace? I would not mind chipping in then never seeing it again if it means I cold have my classic working 'properly'.


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## rodabod

Anyone in London is welcome to borrow mine. I just don't have time to get to a post office I'm afraid.


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## autopilot

rodabod said:


> Anyone in London is welcome to borrow mine. I just don't have time to get to a post office I'm afraid.


Not in London sorry, thanks for the offer though


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## autopilot

If I was to use my own portafilter, would this be suitable? http://www.ebay.co.uk/itm/Air-Pressure-Gauge-for-Compressors-50mm-1-8-BSP-Thread-/280793682904?pt=UK_Air_Tools_and_Compressors&hash=item41609b93d8


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## rodabod

Looks fine. You generally need to buy a reducer to couple the portafilter thread to the gauge's thread.

I bought the wrong reducer size originally as the plumbing measurements confused me (it's not simple to just measure the thread diameter).


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## autopilot

Thanks. Also saw this, but is it suitable for water? http://www.ebay.co.uk/itm/40MM-DIAL-DRY-PRESSURE-GAUGE-0-TO-200PSI-BRASS-BOTTOM-ENTRY-1-8-BSP-DUAL-SCALE-/370747428431?pt=LH_DefaultDomain_3&hash=item565244ce4f

Also, can my portafilter be returned to normal use afterwards?


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## Pablo

autopilot said:


> Thanks. Also saw this, but is it suitable for water? http://www.ebay.co.uk/itm/40MM-DIAL-DRY-PRESSURE-GAUGE-0-TO-200PSI-BRASS-BOTTOM-ENTRY-1-8-BSP-DUAL-SCALE-/370747428431?pt=LH_DefaultDomain_3&hash=item565244ce4f
> 
> Also, can my portafilter be returned to normal use afterwards?


-edit- not entirely sure what is meant by 'dry' pressure gauge. I assume they only recommend it for air/gas.

This one will work as long as you don't mind converting PSI to bar:

http://www.ebay.co.uk/itm/Pressure-Guage1-8-bsp-Bottom-Entry-50mm-dial-0-200-psi-b230-/120873578223?pt=LH_DefaultDomain_3&hash=item1c24a06eef

As rodabod said, you also need the reducing bush:

http://www.ebay.co.uk/itm/3-8-Bsp-Female-1-8-Female-Socket-Reducing-Bush-1-off-/110726500653?pt=LH_DefaultDomain_3&hash=item19c7d0512d

Also, it's probably worth using some PTFE tape on the threads to ensure a good seal.

And yes, you will be able to return the portafilter back to normal. All you're removing is the spout which you screw back in afterwards.


----------



## painty

I guess by dry they might mean it isn't filled with glycerin(e). The idea with the glycerin filled gauges is to dampen down vibration, which sounds ideal for use with vibe pumps. Although not having tried it personally, have seen them used on H-B. I'm trying to find one to fit into the front panel of a machine and the choice is bewildering


----------



## autopilot

I just received an answer from the seller and he says they should be fine for non corrosive liquids, so I might give it a go.


----------



## rodabod

autopilot said:


> I just received an answer from the seller and he says they should be fine for non corrosive liquids, so I might give it a go.


Yes, the air pressure gauges are undamped, but the resonance doesn't wobble the needle too much. You could damp it with some sponge I reckon, if you were fussy.


----------



## Savo

Pablo said:


> This one will work as long as you don't mind converting PSI to bar:
> 
> http://www.ebay.co.uk/itm/Pressure-Guage1-8-bsp-Bottom-Entry-50mm-dial-0-200-psi-b230-/120873578223?pt=LH_DefaultDomain_3&hash=item1c24a06eef


I'm thinking of having a go at this but wanted your thoughts, Would this be ok? I have ordered a reducer.

http://www.ebay.co.uk/itm/40mm-Pressure-Gauge-Base-Entry-0-300-PSI-AIR-AND-OIL-Free-UK-Delivery-/281095805094?pt=LH_DefaultDomain_3&hash=item41729d98a6

Thanks


----------



## rodabod

Looks fine to me.


----------



## narc

My used classic just arrived and the portafilter has two holes in the bottom!? No OPV mod for me unless I buy a new portafilter.


----------



## Pablo

Savo said:


> I'm thinking of having a go at this but wanted your thoughts, Would this be ok? I have ordered a reducer.
> 
> http://www.ebay.co.uk/itm/40mm-Pressure-Gauge-Base-Entry-0-300-PSI-AIR-AND-OIL-Free-UK-Delivery-/281095805094?pt=LH_DefaultDomain_3&hash=item41729d98a6
> 
> Thanks


Yes, looks good







Good price too.


----------



## autopilot

narc said:


> My used classic just arrived and the portafilter has two holes in the bottom!? No OPV mod for me unless I buy a new portafilter.


Why would a portafilter have two holes, any why is your classic coming with a different one? Are you sure your not looking at the two spouts which come off?


----------



## autopilot

.....Ignore....


----------



## Pablo

autopilot said:


> However, is it the same reducer requirement as the ones above?


Yes, same reducing bush as they're all 1/8" BSP thread.


----------



## autopilot

Pablo said:


> Yes, same reducing bush as they're all 1/8" BSP thread.


Yeah, sorry its late, I realised how completely stupid I was being as soon as I posted it. Head is fried from work. Thanks though.


----------



## narc

autopilot said:


> Why would a portafilter have two holes, any why is your classic coming with a different one? Are you sure your not looking at the two spouts which come off?


I have no idea, this is my first machine:


----------



## coffeechap

That is one of the original portafilters with a new handle on it which has been changed at some point, guess u have an older classic as well then


----------



## Savo

My portafilter is the same so I bought another. I thought it might come in handy for double shots in the future but to be honest I've been ok with the one I have.









http://www.ebay.co.uk/itm/Gaggia-classic-portafilter-with-2-shot-baskets-/181124698187?_trksid=p2047675.l2557&ssPageName=STRK%3AMEWNX%3AIT&nma=true&si=P60IMcaJx3nyqMS4J%252FwFJ5qvpi8%253D&orig_cvip=true&rt=nc


----------



## mym

I have a gold plated one of those, I quite like it (when I don't use my naked one) as you can use it to do two singles or a double (the holes are close enough to both feed a single cup).


----------



## jonners

I recently made a gauge that worked fine using these items plus some PTFE tape: 63mm Hydraulic Pressure Gauge Base Or Rear Entry Available-Free UK Delivery | eBay

Connector Air water OIL pipe union adaptor BSP EQUAL STRAIGHT REDUCING NIPPLE | eBay

I bought the 0-300psi base entry gauge and the 1/4BSP X 3/8BSP adaptor. Less than £10 in all.


----------



## Savo

Well the last of the bits came today










Machine nice & clean










The new shower screen from Happy Donkey is different to the original










The brass nut on the OPV is really tight but luckily I had a long socket so it unscrewed ok. I give the allen key a 270 degree turn & tried it, 10 bar!










Happy days


----------



## autopilot

^ how does it take though


----------



## Big Tony

Well I've bitten the bullet and decided to buy this exact same set up to test my pressure. I know that I could have borrowed one from someone but £10 for peace of mind foor years to come will be worth it.


----------



## jodypress

I too will be doing this mod soon. Here are a couple of links for a 90 degree bend and reducing bush.

http://www.ebay.co.uk/itm/220565167817

http://www.ebay.co.uk/itm/220594588050


----------



## autopilot

I used this gauge... http://pages.ebay.com/link/?nav=item.view&id=310666517332&globalID=EBAY-GB

Same seller and it was delivered next day free.

EDIT actually I had the 'bottom entry' (fnar fnar) version from the same seller.


----------



## Savo

autopilot said:


> I used this gauge... http://pages.ebay.com/link/?nav=item.view&id=310666517332&globalID=EBAY-GB
> 
> Same seller and it was delivered next day free.
> 
> EDIT actually I had the 'bottom entry' (fnar fnar) version from the same seller.


I used them too & it arrived the next day with FREE delivery unlike the group seal & shower plate that took nearly a week to arrive from Happy Donkey with £5.10 shipping.


----------



## autopilot

Savo said:


> I used them too & it arrived the next day with FREE delivery unlike the group seal & shower plate that took nearly a week to arrive from Happy Donkey with £5.10 shipping.


Tell me about it. I too paid Happy Donkeys overpriced delivery fee, expecting next day, but nope it took a few days. I'm not really very impressed with Happy Donkey in general, I think they are overpriced anyway. And there is no excuse for that terrible website either, what are they thinking. I won't be shopping there again.


----------



## rodabod

You need to buy their beans at Happy Donkey to make up for the P&P!


----------



## Savo

I just read their shipping policy and realised I shouldn't even have been able to order from them so looks like no Happy Donkey beans for me LOL (I live in Bangor, N.Ireland)

http://www.happydonkey.co.uk/uk-mainland-only.html

I had a moan * HERE*  about it


----------



## Big Tony

Thanks for the links guys. I'm just sticking to the two original linked items and will let you know how I get on. I may even do I video of it to share with others if it's really easy


----------



## Big Tony

All done








video link here

http://coffeeforums.co.uk/showthread.php?10074-Gaggia-Classic-OPV-Mod-My-own-video&p=77283#post77283

let me know your thoughts


----------



## koahhe

If anyone could lend me his portafilter pressure gauge i would pay the postage costs + £5. Thanks


----------



## Gangstarrrrr

koahhe said:


> If anyone could lend me his portafilter pressure gauge i would pay the postage costs + £5. Thanks


I have one you could borrow, just pay the postage (and return it when you're done). PM me if you want it.


----------



## xiuxiuejar

I did mine without a gauge - something to do with measuring water flow etc - and it makes a lot of difference. I have spotted this though and if I had to do it again, circa 20 euros seems a bargain! IF IT FITS THAT IS!!!!!!

http://www.ebay.es/itm/Portafilter-Pressure-Gauge-Kit-3-8-0-16-bar-/130864251129?pt=BI_Hot_Beverage_Brewers&hash=item1e781e00f9


----------



## jeebsy

If you have a Screwfix or something nearby you can get the parts for under a tenner.


----------



## HumStrum

Hi people, I'd also like to adjust my classics OPV. If anybody is in the Newcastle / Northumberland area could I join the list and pay or visit someone local to borrow and return? Message etc....

many thanks!


----------



## Tom James 1976

Hello,

I've just renovated a 10 year old gaggia classic, new pump, new 'stats - its running much better now. I have done the OPV mod using the blind basket but shots are still pouring fast. I've tamped on bathroom scales, put the grinder on nearly the finest (it looks very comparable to expensive preground) but its still hammering out a double in 15 seconds.

Consequently, I think its time to properly measure the group head pressure. Problem is I have an old style classic portafilter with a double spout that doesn't come off. It looks like it would be nearly impossible to mod it to add a pressure gauge....

Is anyone still able to lend me their classic portafliter pressure gauge, or should I head over to ebay?

Happy to pay postage and a bag of beans. I live in East London.

Thanks


----------



## Charliej

Tom James 1976 said:


> Hello,
> 
> I've just renovated a 10 year old gaggia classic, new pump, new 'stats - its running much better now. I have done the OPV mod using the blind basket but shots are still pouring fast. I've tamped on bathroom scales, put the grinder on nearly the finest (it looks very comparable to expensive preground) but its still hammering out a double in 15 seconds.
> 
> Consequently, I think its time to properly measure the group head pressure. Problem is I have an old style classic portafilter with a double spout that doesn't come off. It looks like it would be nearly impossible to mod it to add a pressure gauge....
> 
> Is anyone still able to lend me their classic portafliter pressure gauge, or should I head over to ebay?
> 
> Happy to pay postage and a bag of beans. I live in East London.
> 
> Thanks


What grinder are you using and what coffee too? it may be that your grinder isn't really suitable for espresso so before delving into the internals of your machine once more it may be other factor affecting this.

My Classic is also a pre Phillips one and I have never had any trouble with shots always running too fast that weren't my fault, either not having the grinder dialled in properly or tamp and distribution being at fault, counter intuitively grinding too fine and not having great distribution and tamp can cause the puck to fracture under pressure or develop wormholes and the water will run through the weak points. I only recently measured the static pressure on my Classic and it was sitting at around 10.5 bar so I left it alone. The older Classics weren't put together with pods in mind or pressurised baskets and consequently were usually set to much lower pressure than the newer ones.


----------



## Tom James 1976

Hello,

Grinder is a Gaggia MM - which is ten years old also (I'm wondering about replacing the burrs) but it seems to be consistent. I went to Drurys coffee shop in Covent Garden an bought some decent beans which he ground to 'gaggia level'. Other than that, I buy the best ones they have in the supermarket.

One issue is I took the machine apart for cleaning and curiosity, and completely dismantled the OPV valve. I removed the spring totally! I've reassembled it without problem, but I can't use the 'back off by 3/4 of a turn' rule any more because I don't know where it was set! Hence the wish to properly measure the pressure, along side other factors.

If I grind really fine (kinda iceing sugar) and tamp harder than you should (using bathroom scales) then I can get closer to 25 second shot time, but it's still fast.

I've set the OPV to about 100ml in 30 seconds using the blind basket, but I'd rather just get the pressure spot on....

Any one with a classic pressure portafilter??


----------



## Charliej

OK so you have just identified where the problems lie and it isn't with the OPV on your machine it is most definitely the grinder and the beans. The key to successful espresso making is consistency of grind, and tamp and distribution, the Gaggia MM , whilst it may grind finely is it just doesn't have the consistency for good espresso. Your beans are also a weak link in the chain, even the beans you had pre-ground at Drury's as they can only take a guess at what your machine in your kitchen, with your tamping needs, supermarket beans are, to generalise, stale as soon as you open the packet, how you store your beans can also affect this. Unless you grind to talcum powder and then tamp like a gorilla your shots are going to run fast and no amount of tinkering with the OPV will alter this fact.

Fresh beans and a decent grinder are the cornerstones of making good espresso and the cheapest electric grinder considered to be capable of a decent espresso grind is the Iberital MC2 Auto, they sell used on the forums for around £80-85 and new for about £145 plus delivery. As for fresh beans check out the UK roasters thread in the Beans sub forum and take your pick, if you tell us what sort of tastes you like in coffee we can make some suggestions.

Sorry to sound a little harsh but those are the basic facts: *Garbage IN = Garbage OUT*


----------



## jeebsy

I've got a gauge you can borrow but no longer have the Gaggia portafilter.


----------



## Tom James 1976

jeebsy said:


> I've got a gauge you can borrow but no longer have the Gaggia portafilter.


Hi Jeebsy. Thanks, but I need the portafilter.


----------



## jeebsy

When you say double spout that doesn't come off, is a single hole with a double spout or the really old one with two separate holes?


----------



## Tom James 1976

Hey CharlieJ

Thanks for such a detailed response. When I had the beans ground in Drurys, I specified Gaggia classic and he ground accordingly.

My fear is that because I dismantled the OPV it might be set way off. Should I trust the 100ml in 15 seconds with blind filter in rule? (I can't recall the exact figures right now...I did it to the convention wisdom, whatever that is). However, that measurement seemed a bit inconsistent - it takes a few seconds before the OPV valve kicks in if the head isn't up to pressure...should this reading be taken from having an empty blind or would I start the clock when water appears at the overspill?

So if the grinders not up to the job - do you mean even if its like talc and I tamp way too hard, the INCONSISTENCY of the grind will mean the water will find worm holes?

If I've got a decent grind from Drurys, and I'm tamping fairly well - surely a 15 second shot means the pressures too high? I mean, being a little bit off with grind and tamp shouldn't see a 50% reduction in shot time.....or should it?


----------



## Charliej

Tom James 1976 said:


> Hey CharlieJ
> 
> Thanks for such a detailed response. When I had the beans ground in Drurys, I specified Gaggia classic and he ground accordingly.
> 
> My fear is that because I dismantled the OPV it might be set way off. Should I trust the 100ml in 15 seconds with blind filter in rule? (I can't recall the exact figures right now...I did it to the convention wisdom, whatever that is). However, that measurement seemed a bit inconsistent - it takes a few seconds before the OPV valve kicks in if the head isn't up to pressure...should this reading be taken from having an empty blind or would I start the clock when water appears at the overspill?
> 
> So if the grinders not up to the job - do you mean even if its like talc and I tamp way too hard, the INCONSISTENCY of the grind will mean the water will find worm holes?
> 
> If I've got a decent grind from Drurys, and I'm tamping fairly well - surely a 15 second shot means the pressures too high? I mean, being a little bit off with grind and tamp shouldn't see a 50% reduction in shot time.....or should it?


Hi Tom yes you have got it right regarding the inconsistency of the grind. Even if Drury did grind at a level suitable for a generic Gaggia, was it for a new one with pressurised baskets where the grind isn't so critical or for an older one where the pressure is lower anyway? It is almost impossible for any coffee roaster or shop to get the grind on the nail for your machine in your kitchen on any given day, plus you also have to factor in that ground coffee starts to go stale very quickly. When you say you dismantled the OPV do you mean you also removed the inner threaded part that actually sets the pressure at which it opens?

Regardless of the OPV in order to make good espresso you really need a better grinder and freshly roasted beans, rested for somewhere between 5 -14 days post roast before use, depending on the beans and roaster. An Iberital MC2 which often crop up in the for sale forum for ~£85 is going to be your cheapest option, but as the grinder is such a critical part of the equation, more so than the machine it always wise to buy the grinder you can afford.


----------



## Fevmeister

i would say you can use beans well after 14 days post roasting charlie


----------



## Charliej

Previous post now edited for clarity.


----------



## RedNight

Measuring the pressure with a basket inside the portafilter lead us to a higher output, right? With the triple filter basket on, It is set to 14 bar at the moment.


----------



## rodabod

Set it somewhere between 9 and 10 bar, and you should be in the right ballpark.


----------



## RedNight

Done. It is now right between 9 and 10 bar.


----------



## bazschmaz

Does anyone have one of these I can borrow. I promise to return it.


----------



## Neill

bazschmaz said:


> Does anyone have one of these I can borrow. I promise to return it.


If you have a portafilter you dont mind taking the spouts off you can borrow mine. Only catch is my brother has it in England so you'd have to ask him. You'll find him on here- c_squared.


----------



## bazschmaz

That would be brilliant, thank you so much for the heads up.


----------



## eurorrocket

What a really useful thread. Thanks


----------



## bazschmaz

Brilliant, thanks Neill.









I spoke to your brother too. Thanks for pointing me in his direction.


----------



## Neill

bazschmaz said:


> Brilliant, thanks Neill.
> 
> 
> 
> 
> 
> 
> 
> 
> 
> I spoke to your brother too. Thanks for pointing me in his direction.


No problem. I'm not using it right now anyway.


----------



## mattlindsay

I've just ordered my parts, hopefully have this up and running soon.

Hope I picked well.... I read somewhere that the Gaggia PF was NPT but most people here seem to be saying BSP. I've gone with BSP. From recollection there isn't much difference anyway (I recall that BSP are taper aren't they?)

As an aside, if nobody worked it out.... one way to ease the job of getting your spout off your porta filter is to heat it heavily with a blow torch (obviously take the basket out first!) This weakens the Threadlock glue that would have been used to out it in.

Seemed to work fine for me.

Best of luck everyone


----------



## peterj

For what it's worth, i did the blind adjustment based on return flow rate and then later did the pressure adjustment (a few weeks later), I was 2 bar out...still a lot better because I reckon I starter over 14 bar..


----------



## jj_glos

I picked up the bits off Ebay and found this surprisingly easy to do. I never even used it at default so I'm not aware of any difference! I might put it back at some stage to compare


----------



## GCGlasgow

Just for anyone interested these are still available, I just ordered...had one before but went missing in pay it forward!


----------



## shaunclarke

GCGlasgow said:


> Just for anyone interested these are still available, I just ordered...had one before but went missing in pay it forward!


I have also just ordered the parts from Ebay. Cant wait to do the mod and see if it makes a difference for me!

I also have a brass shower-plate holder coming from The Espresso Shop.


----------



## Dorian

Hi guys, if a pressure guage is still available to borrow I would give it a try with my classic... I just bought a portafilter suitable for connecting the guage. I m ready to pay for shipment costs to Ireland if you can post it.

Thanks in advance,

A.


----------



## Boswell

Great thread. Will be ordering these parts


----------



## rey_one

Hi guys,

I'm really interested in adjusting the pressure of my Gaggia with this method.

It seems all the linked pressure gauges are specified with a maximum operating temperature of 60C, but with a pre-heated machine like in the original guide the temperature will of course be a lot higher. Isn't this a problem for the gauge?

On the other hand, after reading this thread no one complained about a broken gauge ..











tribs said:


> Please note: This assumes your PF thread is 3/8" BSP
> 
> Pressure Gauge
> 
> Reducing Bush


Greetings,

rey_one


----------



## koaly

Hi everyone.

thanks for the great thread and useful hints. I am going to set my Gaggia baby the same way as I am sure it also has extra brewing pressure in the group head.

I have a question about the gauge. The ebay link given on the first page leads to a pneumatic gauge listing. I have got the following reply from the seller: "These dry gauges will not last if used with water as it will corrode the internals. If you want a gauge suitable for use with water you would need glycerine filled..."

These glycerine gauges cost 3 times more.

Do your gauges serve well for and last long despite of the seller's warning?

Thanks in advance


----------



## AndyZap

These are glycerine filled and cost under £10: http://www.ebay.co.uk/itm/Pressure-Gauge-50mm-63mm-100mm-Dial-Bottom-Back-Connection-Hydraulic-Oil-Range-/263052673363?var=562055206067&hash=item3d3f294153:m:mZlLgvFNLg5bx2HR2UlOarg - e.g. 63mm 20 bar version


----------



## koaly

AndyZap said:


> These are glycerine filled and cost under £10: http://www.ebay.co.uk/itm/Pressure-Gauge-50mm-63mm-100mm-Dial-Bottom-Back-Connection-Hydraulic-Oil-Range-/263052673363?var=562055206067&hash=item3d3f294153:m:mZlLgvFNLg5bx2HR2UlOarg - e.g. 63mm 20 bar version


Thank you. It works. I found an option with affordable delivery to my location.


----------



## Zeak

Thanks so much, just ordered. Noticed the glycerine remark right after but think it'll do anyway.


----------



## bol

Late to the party, but wanted to add another voice that this works easily. I ordered from the same company as tribs, arrived very quickly.

Easy to put together, oddly enough I had no issue taking apart my portafilter, take from that what you will. I have a full set of spanners and other tools at home, but a cheap adjustable wrench from B&Q will do the same job for

Finished article.









Of note, I found that vibration in the needle can be solved by making sure the pressure gauge has been purged of air. Pour water in and tap the portafilter itself off the table, that did it for me.

B


----------



## Inspector

Thanks @tribs Ordered this combo too

There are other cheaper gauges on ebay but to find the right reducing bushes is like to find an ice cream shop in desert


----------



## ZappyAd

I bought one of these from Amazon:

https://www.amazon.co.uk/gp/product/B00ONTGKNA

I had already bought a naked portafilter from the same manufacturer which was ok so I thought I would give the gauge a go. Fitting was no problem at all and it seems to work fine. I get a consistent reading and any vibration in the needle is easily fixed with a bit of water initially. My only concern is how well it is calibrated i.e. is the 10 bar I have set it to actually 10 bar. Not sure there is really a way around this other than buying another one and/or doing some kind of overflow test.


----------



## DaveP

ZappyAd said:


> My only concern is how well it is calibrated i.e. is the 10 bar I have set it to actually 10 bar. Not sure there is really a way around this other than buying another one and/or doing some kind of overflow test.


They are 'fairly' accurate..

Setting 10 bar as a static pressure gives about 9 bar in the real world of dynamic pressure.


----------



## ZappyAd

I understand that there is a slight difference between the number on the dial and the actual pressure you get in the portafilter. What I meant is the 10 on the dial actually 10 of static pressure or is it a 5 if you checked it with a fully accurate gauge? Like when my scales say 20g I can check with something that I know weighs 20g to make sure they are calibrated.



DaveP said:


> They are 'fairly' accurate..
> 
> Setting 10 bar as a static pressure gives about 9 bar in the real world of dynamic pressure.


----------



## DaveP

> What I meant is the 10 on the dial actually 10


Ahhhhhh...

Ok then, 'unset' your opv valve (no water being diverted back to the tank) and see if the pressure displayed is approximately the max / working pressure of the pump.

The Ulka 48w ex5 max pressure is in the order of 15 bar (give or take)


----------



## ZappyAd

DaveP said:


> Ahhhhhh...
> 
> Ok then, 'unset' your opv valve (no water being diverted back to the tank) and see if the pressure displayed is approximately the max / working pressure of the pump.
> 
> The Ulka 48w ex5 max pressure is in the order of 15 bar (give or take)


But the dial only goes up to 14









It was reading off the end of the scale when I first used it, so I assume that it was 'too high' and that the 10 I see is going to be a real 10 or less. (Because if the 10 was a real number higher than 10 then the reading wouldn't go off the end of the scale). So I think the pressure I have set it to now is a real 10 or lower, but that still leaves the possibility it is a 5.

I may be overthinking things but I do have a bit of a fear of spending the next 6 months never being able to dial things in and then finding out my pressure valve is set incorrectly! lol


----------



## DaveP

> I may be overthinking things but


Its true


----------



## les24preludes

I've ordered the pressure gauge off eBay. One question - once you've removed the double spout is there any need to put it back if you're only making one cup at a time? Goes some way towards a naked PF....


----------



## JojoS

les24preludes said:


> I've ordered the pressure gauge off eBay. One question - once you've removed the double spout is there any need to put it back if you're only making one cup at a time? Goes some way towards a naked PF....


No need but it is just not the same as a naked.


----------



## Boomingfast

Just wanted to say I have done the OPV mod using a gauge from ebay and thanks to all the useful instructions on here it went exactly to plan and was all done in about 15 mins. My 2008 Classic was reading 12bar before and now 10. I'm a bit new to all this so can't really comment on what effect this has had, but hopefully positive.


----------



## ChiangMaiKevin

les24preludes said:


> I've ordered the pressure gauge off eBay. One question - once you've removed the double spout is there any need to put it back if you're only making one cup at a time? Goes some way towards a naked PF....


You could get single spout...

https://cdn3.volusion.com/wysrt.cnwfk/v/vspfiles/photos/F233-2.jpg?1433160442


----------



## shodjoe1

AndyZap said:


> These are glycerine filled and cost under £10: http://www.ebay.co.uk/itm/Pressure-Gauge-50mm-63mm-100mm-Dial-Bottom-Back-Connection-Hydraulic-Oil-Range-/263052673363?var=562055206067&hash=item3d3f294153:m:mZlLgvFNLg5bx2HR2UlOarg - e.g. 63mm 20 bar version


 Hi.In this version ,do I need different size of that REDucing bush which is 3/8" to 1/8" for the gauge without glycerine?thanks


----------



## AndyZap

shodjoe1 said:


> Hi.In this version ,do I need different size of that REDucing bush which is 3/8" to 1/8" for the gauge without glycerine?thanks


 Indeed, you need to get the correct size to match PF and the gauge thread sizes. I bought mine from Screwfix (mainly because I wanted to try that it fits), but there are plenty online


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## El carajillo

Depending on the diameter of the gauge and the length of the adapter , you may have to remove the drip tray to use the gauge.


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## Zeak

Buying air pressure valve instead of the hydraulic one was a mistake. After two years it looks like it's ruined. My previously 9bars pressure became 4bars when I decided to check. 4bars at most no matter how much I was turning the valve. Then i noticed that last time I've used it, it was gathered liquid inside. Now it doesn't, which made me think it's a gonner. The sad thing is that now I have no clue what my pressure is. Anyone has a suggestion how many degrees from completely shut at least roughly correspond to 9 ish bars? Atm all the proper 1/8 bst gauges are sold out on ebay so I can't even buy one .( anyone selling theirs?


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## ThePeginator

Zeak said:


> Buying air pressure valve instead of the hydraulic one was a mistake. After two years it looks like it's ruined. My previously 9bars pressure became 4bars when I decided to check. 4bars at most no matter how much I was turning the valve. Then i noticed that last time I've used it, it was gathered liquid inside. Now it doesn't, which made me think it's a gonner. The sad thing is that now I have no clue what my pressure is. Anyone has a suggestion how many degrees from completely shut at least roughly correspond to 9 ish bars? Atm all the proper 1/8 bst gauges are sold out on ebay so I can't even buy one .( anyone selling theirs?


Check the OP, both eBay links still link to live products, total price for both £10.. make one and then you've got it forever.

You can borrow mine if you want but by the time I've posted it to you, and you've posted it back, that's £6 at least. I'd just buy one if it was me!

Edit- scratch that, it's also an air gauge. Try and find a liquid one!

Sent from my iPhone using Tapatalk


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## Zeak

ThePeginator said:


> Check the OP, both eBay links still link to live products, total price for both £10.. make one and then you've got it forever.
> 
> You can borrow mine if you want but by the time I've posted it to you, and you've posted it back, that's £6 at least. I'd just buy one if it was me!
> 
> Sent from my iPhone using Tapatalk


 Yeah, I have the one from the OP which is the air one. It didn't last two years.. The hydraulic model that's 1/8 BST is out of stock atm.


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## ThePeginator

Zeak said:


> Yeah, I have the one from the OP which is the air one. It didn't last two years.. The hydraulic model that's 1/8 BST is out of stock atm.


https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F132277427406

14 bar, suitable for liquid, it's 1/8th bsp. That would be a straight swap for your current one.

Sent from my iPhone using Tapatalk


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## Zeak

ThePeginator said:


> https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F132277427406
> 
> 14 bar, suitable for liquid, it's 1/8th bsp. That would be a straight swap for your current one.
> 
> Sent from my iPhone using Tapatalk


 Thanks! Was actually looking at it just now. A bit confused why it doesn't have glycerine inside though or that's fine?


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## ThePeginator

Zeak said:


> Thanks! Was actually looking at it just now. A bit confused why it doesn't have glycerine inside though or that's fine?


Google says it's fine.

Glycerine filled go to higher pressures, they both perform the same function ultimately though.

Sent from my iPhone using Tapatalk


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## Zeak

ThePeginator said:


> Google says it's fine.
> 
> Glycerine filled go to higher pressures, they both perform the same function ultimately though.
> 
> Sent from my iPhone using Tapatalk


 Awesome, thank you!


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## SamV

Does anyone have any recommendations for removing the spout of the Gaggia Portafilter? I've tried the screwdriver trick (2 have snapped) and nail polish remover but it still won't budge!


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## HDAV

SamV said:


> Does anyone have any recommendations for removing the spout of the Gaggia Portafilter? I've tried the screwdriver trick (2 have snapped) and nail polish remover but it still won't budge!


 Did it earlier today boil kettle stick ports filter in for 10 mins to warm and break the seal on the locktite. I put a Parallel punch thought hole and undid it by hand you need a strong bar and a long lever or decent grips/adjustable wrap spout to a protect it and if you have one about filter in a vice use a tea towel to protect


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## Marcros

I put mine in the workmate vice and it allowed me enough purchase to turn it. It wouldn't budge with a long Allen key through the hole, part of the issue being that the hole required a thin gauge of key.


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## SamV

Just tried soaking it in descaler and boiling water and still no luck without a vice. Just to check... are people going anti lockwise looking down at the portafilter as if you were making a coffee or is the portafilter upside down?


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## ratty

It's anti-clockwise looking down the hole at the bolt, to undo it.


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## SamV

Unfortunately, I have tried everything possible to get the spout off with no luck. If anyone is willing to lend a pressure gauge thats already attached to a spare portafilter I'd hugely appreciate it. Obviously I'd pay postage both ways. Cheers!


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## HDAV

SamV said:


> Unfortunately, I have tried everything possible to get the spout off with no luck. If anyone is willing to lend a pressure gauge thats already attached to a spare portafilter I'd hugely appreciate it. Obviously I'd pay postage both ways. Cheers!


 There were a few going around have a search I would lend you mine but need a bottomless porta filter to be getting on with .... do you much in the way of tools? Need a 5mm bar and 8-12" of leverage, a long Allen key and a ring spanner will do it.......

like this grasp filter in left hand spanner in right and push hands apart careful not to slip spanner the 5mm Allen and 17mm are need for opv adjustment anyway


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## SamV

HDAV said:


> There were a few going around have a search I would lend you mine but need a bottomless porta filter to be getting on with .... do you much in the way of tools? Need a 5mm bar and 8-12" of leverage, a long Allen key and a ring spanner will do it.......
> 
> like this grasp filter in left hand spanner in right and push hands apart careful not to slip spanner  the 5mm Allen and 17mm are need for opv adjustment anyway
> 
> View attachment 38867


 Thanks for the tip but still... no luck! Abandoning this project for now till I can borrow a modified portafilter or get to a vice somehow!


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## neilm

Since I've had no luck dismantling my 2019 portafilter, what about one of these (I know it's much more expensive, but saves wrecking tools/portafilter)?

https://www.bluestarcoffee.eu/gaggia-portafilter-pressure-test-gauge-5111-p.asp


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## ratty

I've undone 3 Classic original Portafilters from the mid 80's using an 18 inch adjustable spanner, across the double spout.

After soaking the bottom of the portafilters in puly caff for a good few hours ensuring the plastic handle was not submerged at all, I held the portafilter in a vice with some cloth around it for protection and slowly 'wiggled' the spanner backwards and forwards very slightly with the spanner jaws clamped around the two portafilter spouts, to try and break the 'seal' and then managed to undo them, anticlockwise by the way.

Luckily I happened to have an 18 inch adjustable in my tool kit, if you haven't access a compromise like shown above should work but don't slip, it could be painful!


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## Mikeoffee

I recently got the spout off my 2005 portafilter.

The coating on the base of the inside of the portafilter was cracked and I didn't really fancy drinking coffee that had gone through it, so I had a replacement for coffee production lined up before doing this, and so wasn't too bothered if I messed it up

I used an allen key as in the picture above but belted it with a hammer, rather than trying to lever it, a few good whacks and it was loose. I used a shorter allen key than the pic, and kept the impact near to the spout so as to not bend the key

I can't find the spout to see if it was damaged in anyway, but if you aren't bothered about using it this should do the trick


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## neilm

I've ordered the complete portafilter unit as linked in post #197, no idea when it will arrive (due to virus related delays etc.) but assuming it works reliably I figure this should be more convenient than having to dismantle my current portafilter.


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## HDAV

neilm said:


> I've ordered the complete portafilter unit as linked in post #197, no idea when it will arrive (due to virus related delays etc.) but assuming it works reliably I figure this should be more convenient than having to dismantle my current portafilter.


 It takes less than 30 seconds after the first time (didn't take much longer the first time just more grunt)


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## Votross

neilm said:


> I've ordered the complete portafilter unit as linked in post #197, no idea when it will arrive (due to virus related delays etc.) but assuming it works reliably I figure this should be more convenient than having to dismantle my current portafilter.


 Any update? I'm thinking about ordering the very same portafilter unit.


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## neilm

Votross said:


> Any update? I'm thinking about ordering the very same portafilter unit.


 Not yet - I ordered it on 10 May but due to Covid-19 etc. I have not yet received confirmation that it has actually shipped from Ireland (to the UK), so I'd expect it to arrive sometime next week...


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## neilm

Votross said:


> Any update? I'm thinking about ordering the very same portafilter unit.


 Arrived this morning, one delivery with two components - a fairly cheap/ordinary Gaggia portafilter sans spout, and a Joe Frex Pressure Gauge Kit (product code: xsm)

The pressure gauge kit has a rubber bung in the neck of the gauge - you need to remove this as it wouldn't work with it installed (zero pressure registered).

Also, test without a basket as again there's no pressure registered (at least I couldn't get a pressure reading when testing an IMS 18g competition basket with IMS shower screen).

Without the bung, and without the basket, I'm getting a solid (pointer doesn't fluctuate/flutter) 13 bar from my unmodified 2018/2019 Classic.

PID and OPV spring mod kits have been ordered!


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## Votross

neilm said:


> Arrived this morning, one delivery with two components - a fairly cheap/ordinary Gaggia portafilter sans spout, and a Joe Frex Pressure Gauge Kit (product code: xsm)
> 
> The pressure gauge kit has a rubber bung in the neck of the gauge - you need to remove this as it wouldn't work with it installed (zero pressure registered).
> 
> Also, test without a basket as again there's no pressure registered (at least I couldn't get a pressure reading when testing an IMS 18g competition basket with IMS shower screen).
> 
> Without the bung, and without the basket, I'm getting a solid (pointer doesn't fluctuate/flutter) 13 bar from my unmodified 2018/2019 Classic.
> 
> PID and OPV spring mod kits have been ordered!


 Thanks for the details! I just ordered one for myself.

I had installed an Auber PID controller and IMS brass shower kit a few days ago. Still waiting on a bottomless portafilter, VST 20g basket, and MrShades OPV spring mod kit to arrive.

Can't wait for everything to come together!


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## neilm

I installed the OPV kit over the weekend. Swapped out the factory 12 bar spring (which measured 13 bar on the gauge) with the 9 bar spring (which measures 11 bar on the gauge), so maybe the Joe Frex gauge is measuring +1 bar higher than actual - if so this isn't an issue, just something to be aware of. Assuming I'm right about it registering +1 bar high, then my Classic with 9 bar spring is hopefully now producing 10 bar static pressure.


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## Dave double bean

I have a gauge to lend if anyone wants to borrow one

Sent from my SM-G988B using Tapatalk


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## NitJay

Hi, been reading this with interest and bought one of the guages linked earlier:

https://www.ebay.co.uk/itm/132277427406

I had an absolute nightmare as for some reason I TWICE managed to order the one that only went up to 1bar.

Finally getting the right one, but the seller has pointed out that these are only for use up to 60 degrees.

Two questions

1- has anyone successfully used one to check pressure on a coffee machine without breaking it?

2 - if not, can I just disconnect the heater element and pump water through it to check pressure with cold water?

Due to my own stupidity I'm sick of buying these things, so would love a workaround.

Cheers


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## Agentb

NitJay said:


> 1- has anyone successfully used one to check pressure on a coffee machine without breaking it?
> 
> 2 - if not, can I just disconnect the heater element and pump water through it to check pressure with cold water?


 You should have tagged a free loaner https://coffeeforums.co.uk/topic/22663-one-more-classic-pressure-gauge-available/page/24/#comments

Yes - from cold, switch brew on which pumps cold water into the boiler, then put some cold water in the cold porta filler and test immediately - there is no flow, so will not get anywhere near 60C. hth.


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## NitJay

Thank you, I'll do that.

I wanted to make my own so I could use it again in the future if needed. But yes kind of wish I'd just gone down the loan route now...


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## SamuelG

@SamV

http://www.pidsilvia.com/spoutremove.htm

have a look at the above link. I was having an issue removing my Gaggia spout and this worked instantly. I was pretty impressed how easy it came off!


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## NitJay

Thanks for the help, I got this setup over the weekend.

Have I overdone it though? If so can I just adjust back clockwise to raise pressure? I moved it back a few degrees but didn't seem to make much difference.


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## ElCe

Hi everyone.

Thanks for the all the knowledge sharing here and the great posts.

I've made a Portafilter Pressure Gauge to do the OPV mod using parts from eBay seller 'context-pneumatic-supplies-cpm'

Pressure Guage

Reducing Bush

This is on a 2009 Gaggia Classic.

My problem is that I have very intense needle flutter on my gauge. Seems to fluctuate around 2 bar... Below are links to two videos. A) before the OPV adjustment and B) after OPV adjustment.

I've tried reading around and through the forum but other than possibly using an oil filled gauge or using a 'snubber' I can't find any advice as to how to limit.

Has anyone had the same issue and found any ways to address or even resolve it?

Or any ideas about what the actual reading would be... somewhere in the middle of where the needle is fluttering between... ???

Thanks!

Luke

Video showing Needle Flutter before OPV adjustment






Video showing Needle Flutter after OPV adjustment


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## El carajillo

Try emptying the P/F and gauge then slowly dribble water in until it is completely full.

Carefully fit to M/ch and retry. The jumping about is usually air trapped in the gauge which compresses and rebounds. If it still swings work on the average. between swings.


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## ElCe

Thanks @El carajillo will give it a shot and report back 👍


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## ElCe

El carajillo said:


> Try emptying the P/F and gauge then slowly dribble water in until it is completely full.
> 
> Carefully fit to M/ch and retry. The jumping about is usually air trapped in the gauge which compresses and rebounds. If it still swings work on the average. between swings.


 Managed to make a little progress with this. Have tried a few things, including using a straw and a pipette to try to displace any air in the pressure gague.

The air fluttering of the needle on the pressure guage is still hard to control, but I have had a decent reading. See video below.

Pressure is probably around 8.5 bar. So far this is working ok for me and means I am no longer working at the absolute limit of my grinder, so I'm going to keep it here and see how I get on pulling consistent shots.

Cheers everyone, super helpful to have all your advice here!


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## El carajillo

Look's good to me, there can be a little vibration due to the vibratory action of the pump.

As long as your coffee tastes good stick with it :good:


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## Paul Cooper

Hi, I was just in discussion with MrShades about the OPV kits for the Gaggia Classic, but as I have a 2009 model I can adjust I manually. He also mentioned that it might be possible to borrow or buy a pre-built pressure gauge through this forum, are there any which are still available?

Thanks,

Paul


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## larkim

I'm next in line (just awaiting delivery) for the gauge linked on the "pay it forwards" section of the forum. Post on there and you'll join the queue?


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## larkim

When the gauge arrives here, just wanted to check the protocol:-



Screw gauge to portafilter


Use [empty / full with coffee] basket


Fire up machine - watch for pressure to settle down; looking for 10 bar; if achieved, job done


If over / under 10 bar, fettle under the hood as appropriate


Repeat from stage 2


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## larkim

Paul Cooper said:


> Hi, I was just in discussion with MrShades about the OPV kits for the Gaggia Classic, but as I have a 2009 model I can adjust I manually. He also mentioned that it might be possible to borrow or buy a pre-built pressure gauge through this forum, are there any which are still available?
> 
> Thanks,
> 
> Paul


 Paul - I'll be finished by tomorrow with the OPV that's available via the Pay It Forward thread. If you dive in there (just for completeness of the process I think) to get in the queue (and I think you'd be the first in line at the moment) I'll get it stuck in the post for you.


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## Bagpu55

Double checking do you test with the machine cold or when its running up at temperature? Thanks


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## larkim

I did both hot and cold, got the same result.


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## MrShades

larkim said:


> When the gauge arrives here, just wanted to check the protocol:-
> 
> 
> 
> Screw gauge to portafilter
> 
> 
> Use [empty / full with coffee] basket
> 
> 
> Fire up machine - watch for pressure to settle down; looking for 10 bar; if achieved, job done
> 
> 
> If over / under 10 bar, fettle under the hood as appropriate
> 
> 
> Repeat from stage 2


 DON'T have a basket in the portafilter at all - empty or full; otherwise you'll get water flying out and it won't seal properly.

Remove any basket and the PF will lock in, but quite a bit further round.


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## larkim

MrShades said:


> DON'T have a basket in the portafilter at all - empty or full; otherwise you'll get water flying out and it won't seal properly.
> 
> Remove any basket and the PF will lock in, but quite a bit further round.


 That would explain a lot!! I did with and without and without was leak free 🙂


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## Baz

Hi

Just wondering if this is still going. And if so if I can get in it turn

Thank you


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## Matty1080

I'm on making my pressure gauge up at the minute and reading through this topic is the general consensus still 10 bar at the portafilter for a 9 bar pressure when pulling a shot?


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## MrShades

Matty1080 said:


> I'm on making my pressure gauge up at the minute and reading through this topic is the general consensus still 10 bar at the portafilter for a 9 bar pressure when pulling a shot?


 Yes


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