# Gaggia Classic OPV Mod - Allen Key Won't Budge



## Mouzone (Dec 9, 2017)

I've managed to get to the final stage of the mod but I can't actually turn the Allen key! It slots in perfectly (5mm) but it just won't turn anticlockwise. I've even tried gripping the Allen key with pliers but it just won't move.

Has anyone got any tips?

For some reason I can't find anyone else on the internet with the same problem as me!

Thanks


----------



## Chris 81 (Jan 4, 2018)

Exactly the same problem as I've had this week.

I'm happy to say I sorted the issue out today but didn't have time to post results!

Basically I tried everything. Pliers on allen key, light taps with hammer, no joy. So ended up taking the whole valve out and taking it to a local garage workshop to ask if I could use their vice for 5 minutes!

The valve was open on a vice using a rachet hex key 5mm. Maybe it was down to descale, maybe it's age (2007) but it was stuck solid! No way I could of moved that inside the machine.

I'm definitely no expert so check with other members on here, but a few tips might help..

Always use an extension for the OPV nut, and a 5mm hex rachet set with extension fitted. There's a lot of sharp edges inside and you definitely don't want to cut yourself open!

Last night I put a drop of oil in the adjuster part of the valve. Maybe that helped losen it up overnight. Or as someone recommended on my post try leaving it in descale over night.

If you look for my post in the technical issue section asking about OPV Pressure gauge test, lots of helpful advice.

Good luck!


----------



## Mouzone (Dec 9, 2017)

Chris 81 said:


> Exactly the same problem as I've had this week.
> 
> I'm happy to say I sorted the issue out today but didn't have time to post results!
> 
> ...


Thanks Chris. Very coincidental to both come across the same problem around the same time, which does seem rare.

I had actually seen your thread at the weekend but at that point this issue hadn't cropped up! Nothing showed in Google or this sub-forum (I should have checked the Technical one - sorry mods)

Appreciate the advice. I was slightly hesitant to disassemble any part of the inner machine but it sounds like this is the only possibility. I will go for the olive oil drop and try descaler over night. If no luck I will find a vice at the weekend if no luck with descaling etc.

The only thing I'm confused about is that in your thread you had yours turning at one stage? Mine looks like it will never turn.

I picked myself up a socket wrench set with an extension, which greatly helped in getting that stiff nut off - practically impossible with an adjustable spanner (and I have the battle scars to prove it!)


----------



## Chris 81 (Jan 4, 2018)

I did manage to move it slightly during 1st attempt, but as someone mentioned the inside was fairly rounded off. There was no change to the pressure reading after so guess I only managed a slight movement of the allen key before it became stuck.

I still have to use pliers to adjust but it turns easy enough now.

I'll probably buy a spare valve anyway and will replace it at some point, but for now...COFFEE!!


----------



## MartinB (May 8, 2011)

Where are you based? Have you tried a 't' handled allen key?


----------



## Mouzone (Dec 9, 2017)

MartinB said:


> Where are you based? Have you tried a 't' handled allen key?


Colchester, Essex but I'm in London (Fenchurch St) Monday to Friday.

I haven't, just been using an L shaped one. I will pick up a 'T' one today and see if it helps.

My concern was that it feels absolutely locked in and won't budge. In everybody else's videos and posts that I've come across it seems to turn relatively effortlessly. I.e. nobody (except Chris) has highlighted any difficulty with physically being able to turn it.


----------



## MartinB (May 8, 2011)

I've encountered a fair few classics and haven't come across this issue before - so it's also new to me!

I more than likely will have a spare OPV - happy to check the 5mm bolt and could pop it in the for sale section for you?


----------



## ashcroc (Oct 28, 2016)

It can be a bit tricky to crack especially if it hasn't been adjusted in a while (or in most cases since it was built).

My ratchet multibit screwdriver handily has a hole in the handle so I could use a screwdriver as a T-bar for extra leverage. If you're using right angle allen keys a socket extension can work.


----------



## AndyZap (Dec 29, 2016)

Descaler + WD40 (do not remember in which order) helped in my case. But you do need to remove OPV from the machine, so you can clean it well after all these chemicals


----------



## Mouzone (Dec 9, 2017)

Thanks all. I'm going to give it another go tonight, I've got a screwdriver with a 5mm hex key so will see if that helps (couldn't get a 'T').

If still unsuccessful, it's going for an overnight bath in descaler as punishment.

@MartinB thanks for the offer - I will see if I can make do with this one, otherwise I'll let you know.

Cheers


----------



## Mouzone (Dec 9, 2017)

So the screwdriver with a 5mm hex head worked (to some extent). I'm currently reading at about 10.5/11 bar though I am struggling to get it to turn anymore. I have probably adjusted it about 5 or 6 times (massively overestimating how much I've turned it each time).

Once the palm of my hand has stopped burning from the tight grip twist I will give it one last go and see if I can get it down any further.

Is 10.5/11 bar going to be a significant improvement to the 14+ bar it was reading at before? Im reluctant to go all in with disassembly if the benefit is minimal.


----------



## El carajillo (Mar 16, 2013)

From your description it would seem it has been neglected for a long time. If the adjuster is so solidly seized the spring and seal underneath would also benefit from a thorough clean / de-scale also the seat for the seal. Is the thread above the adjuster scale free ? If so it should unscrew fairly easily.

The reason it will not screw down is probably because the lower threads have scale on them.

If you leave it overnight with some d / scaler in it will probably unscrew easily AM. Be sure to flush with plenty of fresh water afterwards.


----------



## Mouzone (Dec 9, 2017)

El carajillo said:


> From your description it would seem it has been neglected for a long time. If the adjuster is so solidly seized the spring and seal underneath would also benefit from a thorough clean / de-scale also the seat for the seal. Is the thread above the adjuster scale free ? If so it should unscrew fairly easily.
> 
> The reason it will not screw down is probably because the lower threads have scale on them.
> 
> If you leave it overnight with some d / scaler in it will probably unscrew easily AM. Be sure to flush with plenty of fresh water afterwards.


I think you are right. I've only had it a few weeks but when I gave it a good clean and replaced the head gasket at the weekend, I did notice some aspects that suggested a bit of neglect. I was quite amazed by the state of the dispersion disc (which is now nice and clean).

It therefore wouldn't surprise me if there was a bit of scale in the grooves of the OPV. I'll be making sure it's well looked after.

In the end I managed to get the OPV adjusted with the use of a screwdriver through the hole in the handle of the other screwdriver with the hex head bit. This gave me the leverage and made it much easier to do. I wish I'd realised how much easier that would make it before!

I'm happy that the OPV is now on the money (after a good 10-15 attempts I reckon!). I pulled a shot and gave it a little taste (it was late last night and didn't want to ruin my night's sleep). I don't know if it's psychological but I am very happy with the outcome. It tasted significantly nicer and I could really notice the flavour of the beans more than before (perhaps a bit burnt / bitter before).

Thank you all for your help.


----------



## ratty (Sep 22, 2019)

I've got the same problem and have even tried an eighteen inch adjustable spanner on a long arm 5mm key for extra leverage . Looks like it has to come off which I was hoping to avoid having recently bought the refurbished machine. I am a retired Mechanical Engineer so I'm not fazed at all by it, just not too happy!


----------



## ashcroc (Oct 28, 2016)

ratty said:


> I've got the same problem and have even tried an eighteen inch adjustable spanner on a long arm 5mm key for extra leverage . Looks like it has to come off which I was hoping to avoid having recently bought the refurbished machine. I am a retired Mechanical Engineer so I'm not fazed at all by it, just not too happy!


Allen key socket on a breaker bar should work.


----------



## ashcroc (Oct 28, 2016)

ratty said:


> I've got the same problem and have even tried an eighteen inch adjustable spanner on a long arm 5mm key for extra leverage . Looks like it has to come off which I was hoping to avoid having recently bought the refurbished machine. I am a retired Mechanical Engineer so I'm not fazed at all by it, just not too happy!


Another option if you have an impact wrench.


----------



## ratty (Sep 22, 2019)

Cheers,

Got a depleted tool set nowadays, believe it or not impact wrench fell apart a year or two ago and has not been replaced.

I will go round a mates home workshop when I get it out in the week, if it requires more drastic action than I've got at home.

I've ordered O ring and gasket set from ebay too.


----------



## Norvin (Sep 10, 2014)

I struggled with one yesterday. The square section on the OPV body is ideal for gripping in a vice. I used a 1/4 socket with a breaker bar to get leverage. I used penetrating oil to loosen it then found a little bit of copaslip on the threads made a lot of difference.

The four boiler screws were a different matter...


----------



## ashcroc (Oct 28, 2016)

I wonder if descaling with a blind basket fitted to blast it through the OPV would help.


----------



## ratty (Sep 22, 2019)

Can understand! I've sprayed the boiler bolts with GT85 in preparation.

I had to find a thin tube off another squirty thing (lost the GT85 one!) otherwise the spray would have gone everywhere!

Sorry out of synch here. I'm a slow typist!


----------



## ratty (Sep 22, 2019)

I got the OPV up to my friends workshop, we got it in a proper vice (mine at home is a baby thing!)

5mm Key inserted and it spun in the hexagon socket, rounded off, innit!

I know there are other means of extraction which at some point will be adopted just to see the result.

Ordered a new one from MrBean2Cup.

Will get there eventually!


----------



## El carajillo (Mar 16, 2013)

Norvin said:


> I struggled with one yesterday. The square section on the OPV body is ideal for gripping in a vice. I used a 1/4 socket with a breaker bar to get leverage. I used penetrating oil to loosen it then found a little bit of copaslip on the threads made a lot of difference.
> 
> The four boiler screws were a different matter...


 Hope you cleaned all the Copaslip off afterwards= it is toxic. Don't fancy Copaslip in the return to yank water.


----------



## ratty (Sep 22, 2019)

Cost of the new OPV from MrBeanToCup was £39.89

Best price I could find online.


----------



## Norvin (Sep 10, 2014)

Yes, all thoroughly cleaned off. Had an aromatic smell in the kitchen from the residue of GT85 on the outside of the boiler when it first heated up.

I once stripped the hex in the plug once. Had to drill it out on the lathe. I remember that the thread in the OPV body is a non preferred spec (or so I thought at the time), very fine for the diameter, probably so in order to achieve fine adjustments.


----------



## ratty (Sep 22, 2019)

Norvin said:


> Yes, all thoroughly cleaned off. Had an aromatic smell in the kitchen from the residue of GT85 on the outside of the boiler when it first heated up.
> 
> I once stripped the hex in the plug once. Had to drill it out on the lathe. I remember that the thread in the OPV body is a non preferred spec (or so I thought at the time), very fine for the diameter, probably so in order to achieve fine adjustments.


 Were you able to get a replacement socket head set screw for the OPV then if the thread was not standard, or was the OPV scrap?


----------



## Norvin (Sep 10, 2014)

ratty said:


> Were you able to get a replacement socket head set screw for the OPV then if the thread was not standard, or was the OPV scrap?


 Can't remember exactly but I think that the only items that I could find with that thread were car brake related and weren't suitable. In the end I made a spacer with a hole in the middle that was held in place by the top nut. The length was adjusted to get the right amount of spring compression to get 9 bar by using shims.

Just remembered that I had a similar problem with a Gaggia OWC OPV valve. I got around that by making an aluminium tool with three holes in it, see picture. Using two holes in the tool as a guide, drill two holes in the plug and using two old drill shanks through the tool and the plug use the third hole to unscrew the plug. The new holes in the plug won't affect the operation of the OPV.


----------



## El carajillo (Mar 16, 2013)

Norvin said:


> Yes, all thoroughly cleaned off. Had an aromatic smell in the kitchen from the residue of GT85 on the outside of the boiler when it first heated up.
> 
> I once stripped the hex in the plug once. Had to drill it out on the lathe. I remember that the thread in the OPV body is a non preferred spec (or so I thought at the time), very fine for the diameter, probably so in order to achieve fine adjustments.


 The 'perfume' from GT85 is far more pleasant than WD40, the best penetrant is Plusgas----- but it STINKS :yuk: :classic_biggrin:


----------



## ratty (Sep 22, 2019)

Norvin said:


> Can't remember exactly but I think that the only items that I could find with that thread were car brake related and weren't suitable. In the end I made a spacer with a hole in the middle that was held in place by the top nut. The length was adjusted to get the right amount of spring compression to get 9 bar by using shims.
> 
> Just remembered that I had a similar problem with a Gaggia OWC OPV valve. I got around that by making an aluminium tool with three holes in it, see picture. Using two holes in the tool as a guide, drill two holes in the plug and using two old drill shanks through the tool and the plug use the third hole to unscrew the plug. The new holes in the plug won't affect the operation of the OPV.
> 
> View attachment 33696


 Well done that man!

Brilliant bit of innovation so that you could still use the original set screw.


----------



## ratty (Sep 22, 2019)

Fast response from MrBean2Cup, new OPV arrived in the post at 12.45pm it took 22 hours from ordering the part.

Not bad for Post Office second class!

Set to go again now but not enough time left today to start as I'm fitting MrShades PID kit whilst the machine's down, at the same time.

Bit of a learning curve as it's the first time I've ever opened one up!

Great instructions nowadays with videos and also Mr Shades excellent instructions.

Busy tomorrow all day too, so it will be Fri, Sat or Sun whenever I've got a free day to put aside, just in case of any hitches.

Is there anything to use on the OPV threads to aid adjustment/removal down the line, that won't cause any taste issues?

Should I unscrew the 5mm hex set screw in the OPV 3/4 of a turn before replacing to get nearer to the 10 bar setting?

Cheers for all the help folks and I will work on the original OPV given time.


----------



## ratty (Sep 22, 2019)

Well I got the PID kit fitted today. Great instructions from MR.S.

Electrickery is a bit of of a dark art to me being mechanical!

I switched it on and it was reading 80 and seemed to be behaving itself.

I didn't program it any further as I had got through 3/4 bottle of Rioja and thought it politic to stop working at that point.

I had fitted the new OPV first and put some molykite 111 on the threads, belt and braces and all that!

I measured the depth of the 5mm set screw from the end of the OPV, it was 11.5mm. The old one that was rounded off measured 12.3mm depth, and other dimensions appeared the same over the two items, but I couldn't gain much info really from that.

I returned the screw to the 11.5mm depth as a starting point. I will reset it to 9.5 bar when I have the PID kit fully functional.

It's all go isn't it??

Forgot to say while I was looking for an OPV replacement, I had an interesting talk with some people.

Watch this space and I will update if it comes to fruition.


----------

