# OPV mod for ancient Gaggia Classic?



## SplitShot (Jul 23, 2021)

Hi I have just joined up this is my first post. I have been using my 2004 Gaggia Classic since buying it new, with a Lux conical burr grinder I got at the same time. I got OK ish results, and never really thought about it much apart from the coffee was quite a bit better than "Instant" swill.

Recently I was looking for some de-scaler on t'interweb, and was surprised to find that the Gaggia Classic is erm, well, a classic, and that it's actually quite good. Who knew? Well everyone but me I guess.. And even more intriguing you can trick it out with some pimpery to make it even better! I am starting to get up to speed with modern coffee culture - I have some scales ordered, and I am relegating my stupid shot glasses to making Gin and Tonic. I am also hanging my nose over a new steam wand and some other bits.

So - I am after some informed thought - I see that the Classic can be modded to reduce the brew pressure to 9bar or whatever - the OPV mod. I don't have a pressure gauge but could probably get one to measure my pressure, but wanted to ask this before I went to the trouble of doing that...

As I understand it the pressure was increased to cope with pods which need 15bar or so, which is then higher than ideal for actual espresso making. Does anyone know when that started happening - I wondered if maybe my old 2004 machine is possibly set to around the old medieval 9bar value? - (I can't remember if pods were all that popular in 2004 - I can remember someone giving me a shot from some sort of "new fangled pod" based gadget in John Lewis around that time and thinking I make better tasting coffee than that on my Gaggia thanks .. !)

In short - is the machine from that era likely to need OPV modding?

Anyway thanks for any help - I think I may found a new hobby!


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## allikat (Jan 27, 2020)

In short: Yes.

I have a 2001 Classic and it can be rough guesstimated into the right ballpark pretty easily without a gauge. I forget the exact amount, but I think it's a half turn on the screw (assuming it's not frozen up with scale). Others will be able to tell you the direction and amount needed to get it roughly right from stock. I've done it on a Classic and a Baby from that era, and the Classic hit 8.5Bar, the Baby got to 9 with the mod just with the right twist. I did later get a gauge, and both machines were close enough I didn't feel a need to adjust them.


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## ratty (Sep 22, 2019)

SplitShot said:


> In short - is the machine from that era likely to need OPV modding?


 If not done already the machine will need The OPV lowered to 9 bar.

The oldest Classic I've worked on a 1997, was set at 15 bar and needed to be lowered to 9 bar.

I've worked on lots of early 2000 models and all need the OPV lowered to 9 bar, if not already done.

A low cost portafilter pressure gauge can be bought with the correct thread connector once the current spout has been removed. It usually needs PTFE on the portafilter thread to stop leakage.

https://www.ebay.co.uk/itm/161207194396?hash=item2588b2931c:g:N7EAAOSwAF5UZ2~1


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## SplitShot (Jul 23, 2021)

Brilliant thanks Allikat and Ratty that is all I needed to know - much appreciate your rapid respones. I will have a look into that. I expect to be back soon having sheared something threaded off the Gaggia trying to improve it! Thanks again


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## ratty (Sep 22, 2019)

If you decide to go down the portafilter pressure gauge route, check that your portafilter does have the thread in the middle of the bottom of the portafilter. Some early portafilters do not have the threaded part rather a cast one or two piece spout as part of the cast, without a thread. If you have a thread then the spout can be very tight to remove. I usually grip it with an 18" adjustable spanner to start it off in a vice, but not everyone has one. It can be started off with smaller tools and a hammer to shock it to start it undoing.


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## SplitShot (Jul 23, 2021)

That's really helpful thanks for that I will check that before I get out the pnuematic breaker, good to know before trashing it! Cheers for that


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## bbstrikesagain (Aug 15, 2021)

For what it's worth I really like the look of the Edesia Espresso gauge (https://www.ebay.co.uk/itm/281465311077), stainless, and a rubber washer means you can fasten at any angle and no need of PTFE tape or brute force - it doesn't rely on the thread taper. Maybe a fiver more than the other, but probably worth it? I even checked my spout comes off, no problem with aluminium jaw protectors in a vice. Yeah, I'm an engineer, not a barista..

But instead I went for the Shades of Coffee spring kit, as my Classic isn't an adjustable OPV and I'll be happy to learn to work with 9 bar or thereabouts for starters. Fitted in five minutes.


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