# Gaggia Classic low pressure advice needed



## ratty (Sep 22, 2019)

Seems to have me beat for the moment!

I've fitted the PID and that's running as I've set it. 93C boiler temp and 137C for steam

New OPV fitted

Used cleaner and descaler on the boiler and head group on the strip down

New shower screen and silicon group gasket.

Removed and cleaned solenoid valve (it wasn't bad)

Getting extremely low pressure although water coming out of the head looking good without portafilter in, and the steamer's steaming well.

I put in the blind basket with a pressure gauge on the portafilter and getting about 1/8 inch of water in the basket, and the machine's not changing tone and not releasing any more water into the blind basket.

When I released the portafilter there was a small surge of pressured water in and around the stainless steel tube outlet from the OPV

I've blew a mouthful of water through the pump tube so don't think it's an air lock but I don't know?

Any ideas? Could it be the pump had it?

I attempted an espresso and the water pooled on top of the puck quite a bit although I did get an almost drinkable shot come through!


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## El carajillo (Mar 16, 2013)

It sounds as if there is a problem with the pump, a quick test for flow volume--- without the P/F in place run the pump for 30 seconds into a measuring vessel OR do it by mass (weight)

You should have approx 130ml in the 30 sec pull.

If you have a pressure gauge for your P/F check running pressure.

You can dismantle the pump and check for debris/partial blockage or damaged components. I did have the main spring break on mine


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## ratty (Sep 22, 2019)

Apologies.

I had a senior moment and was trying to set the pressure with the blind basket in the PF! ? ?

That'll teach me to think I have it sussed with only one read, and me with my elderly retention ability.

All good now.

Thanks for replying. ?


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## ashcroc (Oct 28, 2016)

ratty said:


> Apologies.
> I had a senior moment and was trying to set the pressure with the blind basket in the PF!
> That'll teach me to think I have it sussed with only one read, and me with my elderly retention ability.
> All good now.
> Thanks for replying.


That'll give you a low pressure reading every time!


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## Mr_strange (Oct 20, 2020)

My Gaggia classic draws about 190ml though the brewhead in 30 secs, but pressure is too low to make an espresso with quality fine ground coffee. Pump struggles / rattles and nothing comes out (think it flows back through return valve) unless I don't tamp. Is this normal?


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## Nightrider_1uk (Apr 26, 2020)

ratty said:


> I put in the blind basket with a pressure gauge on the portafilter and getting about 1/8 inch of water in the basket, and the machine's not changing tone and not releasing any more water into the blind basket.


 Just read this thread, as it has popped up as a recent update. I had to read this a few times, thinking, that don't make sense, (but your'e a seasoned refurbisher); then read your apologies post and finally read Tuesdays post and clocked that the original post is 11 months old. Well I have had a couple of large scotches tonight.


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## Nightrider_1uk (Apr 26, 2020)

Mr_strange said:


> My Gaggia classic draws about 190ml though the brewhead in 30 secs, but pressure is too low to make an espresso with quality fine ground coffee. Pump struggles / rattles and nothing comes out (think it flows back through return valve) unless I don't tamp. Is this normal?


 Are you grinding the beans yourself or is it pre-ground, also how hard are you tamping?


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## Alfieboy (Dec 26, 2018)

Mr_strange said:


> My Gaggia classic draws about 190ml though the brewhead in 30 secs, but pressure is too low to make an espresso with quality fine ground coffee. Pump struggles / rattles and nothing comes out (think it flows back through return valve) unless I don't tamp. Is this normal?


 Mine does this with very fine grinds from the Mignon or bought pre ground

I found levelling and the right quantity enough to produce a nice drink so I've stuck with that


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