# Gaggia Classic expressing too quickley



## mersey weigh (Sep 10, 2015)

gaggia classic Problem. It has started expressing too quickly (8 seconds double shot) and before anyone mentions the coffee grind is too coarse, I'm using pre ground espresso as a test coffee for standardisation. I also have another classic machine in work using the same coffee to compare.

I have fully stripped the machine down and re-built.

Solenoid is working as Fine, OPV is working fine and if I back wind the OPV so it releases a bit of water as I make a shot, the machine still expresses at a rapid rate, with dreadful results. It is almost as though there is no build up of back pressure to force through the coffee. I have inspected the inside of the boiler chamber, there is no scale and all of the apertures/pipes/gaskets are in good working order and there are no leaks from the portafilter when running

The machine did work fine up until last week, so there has been some sort of failure that I cannot find. Can anyone help?

Alex


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## jeebsy (May 5, 2013)

It's the pre ground


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## timmyjj21 (May 10, 2015)

Its the pre ground coffee. Alternatively could just be the different pumps. I had the usual Ulkla pump in my Classic, then swapped it for a very old Invensys and discovered a missive difference. The old Invensys was so much stronger, despite the OPV being the same and the pressure reading the same at the group head.


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## ronsil (Mar 8, 2012)

Using pre ground with any espresso machine will not give consistent results.

What's the water flow like from the grouphead without coffee? If its poor then as above I think you need to look at your pump


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## Fevmeister (Oct 21, 2013)

expressing is a new one


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## Jumbo Ratty (Jan 12, 2015)

Fevmeister said:


> expressing is a new one


Been in use for a long time.

express1

ɪkˈsprɛs,ɛk-/

verb

gerund or present participle: *expressing*

"she must withdraw to express her milk in private"

squeeze out, press out, wring out, force out, extract, expell "the grapes are trodden until all the juice is expressed"


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## Fevmeister (Oct 21, 2013)

Jumbo Ratty said:


> Been in use for a long time.
> 
> express1
> 
> ...


*'Expressing*  is a way of taking breastmilk from your breast without your baby needing to suckle. You can do this by using: your hands. a manual pump. an electric pump.'

would make an interesting milk based drink


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## Fevmeister (Oct 21, 2013)

mod delete


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## Jon (Dec 3, 2010)

Posts #2 / #3 / #4 have this covered. Pre-ground isn't going to consistently/reliably give you the results you might want...


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## destiny (Jun 4, 2015)

Out of curiosity, how much did the flow change on your grind settings when you dropped the pressure with the OPV mod? Did you have to adjust by much?


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## Kyle548 (Jan 24, 2013)

Obviously the Classic is broken.

I can't see why preground would give you any problem at all.


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## seeq (Jul 9, 2011)

Are you using a pressurised basket? That could be broked.


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## mersey weigh (Sep 10, 2015)

Hi

To everyone and thanks for your responses.

Firstly, please understand, it's not the coffee grind. I am using the same coffee, from the same container as before the fault arose. I know its old coffee but at this point I'm not bothered about the taste of the coffee, I want to resolve the fault that has occurred.

I also have another Gaggia classic as a direct comparison in my workshop where I have both machines.

Apologies for using the word expressing , I am new to this forum. I'm sure the senior members who found it amusing can correct me and maybe they could post the correct terminology I should be using.

In answer to the more serious questions:

Thank you for highlighting the pump, which may be the source of the fault. However, there is no significant change in tone or operation when running but I will investigate.

The flow from the grouphead without coffee is pretty much the same as with coffee

If I adjust the OPV the flow is the same (way too fast), if I over adjust the OP, so over pressure water flows quite quickly back into the water chamber, the flow is slower but the resulting coffee is the same, its as if the coffee is not getting the pressured water forced through the grind


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## jeebsy (May 5, 2013)

It's the coffee.


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## Jumbo Ratty (Jan 12, 2015)

Expressed was used correctly.

Now thats out the way can you confirm that the baskets being used on both machines are either pressurised or non pressurised and are the same on both machines.

Pressurised will have lots of holes on the inside but only one exit hole underneath on the bottom, they mask this by making it look like there are lots of holes but this is merely indentations.

How old is the pre ground ? how long has the packet been opened for?


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## timmyjj21 (May 10, 2015)

At one stage or another I have had up to 5 classics sitting behind the living room couch that I have repaired for fun. Each one has been subtly different. Pump age, shower screen age and hole size variation, tamp pressure...all create so many variables I don't think you can compare between machines. I mention the pump brand because it was so noticeable to me, but I honestly think that if the machine is pushing out a good coffee, normal flow rate and pressure, then it isn't broken. Possibly the one that you think is 'working' actually has the problem, as your current one has the faster flow rate? Pre ground dead coffee is not an ideal test material IMHO.


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## mersey weigh (Sep 10, 2015)

Jumbo Ratty said:


> Expressed was used correctly.
> 
> Now thats out the way can you confirm that the baskets being used on both machines are either pressurised or non pressurised and are the same on both machines.
> 
> ...


Hi thanks,

the baskets are both non pressurised

coffee is two weeks old Lavzza espresso sealed airtight in freezer


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## mersey weigh (Sep 10, 2015)

Hi and thanks for your interst, the faulty machine (described) flows coffee out at a very fast rate, has no creme and tastes like a sack of sh***, but before the fault occured, made a pretty good standard shot


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## Fevmeister (Oct 21, 2013)

mersey weigh said:


> Hi thanks,
> 
> the baskets are both non pressurised
> 
> coffee is two weeks old Lavzza espresso sealed airtight in freezer


that's why then

dont freeze, dont seal air tight unless you have an escape valve, dont use preground, dont use lavazza


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## Jumbo Ratty (Jan 12, 2015)

mersey weigh said:


> Hi and thanks for your interst, the faulty machine (described) flows coffee out at a very fast rate, has no creme and tastes like a sack of sh***, but before the fault occured, made a pretty good standard shot


This is ringing some bells in my memory that this could be because the water is too hot. Im sure Ive seen a problem on here that was how you describe and it turned out to be the thermostat wasnt working properly.

Anyone? would the water being too hot create this problem


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## Jon (Dec 3, 2010)

Regardless of the fault - or not - the preground is really not going to be helping you on any level...


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## Dallah (Jan 31, 2015)

Fevmeister said:


> mod delete


why would I delete Paul Weller? I'm confused.


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## Sk8-bizarre (Jan 22, 2015)

Jumbo Ratty said:


> Been in use for a long time.
> 
> express1
> 
> ...


Oi you, off the fəˈnɛtɪks that's my turf.


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## bulletjie (Aug 31, 2015)

Try different coffee before putting blame on machine. You never know. It is ONE of several variables which you need to eliminate.


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## Sk8-bizarre (Jan 22, 2015)

Take a video of the water running out of the head with no PF in and post it.


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## seeq (Jul 9, 2011)

Pre ground is going to pour out if not using a pressurised basket. I'm surprised it doesn't in your work machine and actually wouldn't be surprised if the home one is working correctly and the work one isn't. After cleaning your home one it will only pout quicker, perhaps your work one is scaled/clogged up?

Pre ground is far too course for espresso in a standard basket. To me 8 seconds sounds about right.


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