Hi everyone,

First time poster here. I have searched the internet and have not found anything conclusive on the issue of fluctuating pressure during the shot.

It started with the machine totally clogged and not dispensing water. So I search and found quite a few helpful demonstrations on how to trouble shoot it. Found out the pipe from thermal head to solenoid was totally clogged. I opened it up and thoroughly cleaned it. The machine started working again with great pressure at the wand. But the pressure gauge started fluctuating and wouldn't hold constant pressure.

On some recommendation on the internet I did blind test and dual filter tests. It still doesn't hold good steady pressure. Currently I have to grind the coffee really fine to make any pressure and even then it would fluctuate. Needless to say the shots have been pretty bad.
Upon reading further I found out that sometimes the OPV can get bad since it's made out of plastic. so I went ahead and replace that but the symptoms still persist.
The next step for me would be to replace the pump as it might be getting weak. Keep in mind the machine is almost 4-5 years old.

Just wanted to check if anyone has come across this and if changing the pump would be the right step.

Thanks in advance

Videos:

What was the pipe clogged with?
Has the machine been descaled?

How much does the pressure fluctuate?

The Brevilles have about a bazillion silicone o-ring keeping the water in and they fail in funny ways. Check inside for any water leaks.

The pipe had calcium build up. So after opening it up I descaled the whole machine.
Pressure goes between 2-3 to 7-8 bars

If you haven't seen this, it goes over the 870 water flow.
Pump action could be voltage which could be a dirty connection or bad crimp.

Thanks for sharing. Yes that was my go to video for trouble shooting initial water clog. But now I have the issue with fluctuation on the pressure.
BTW, another fact I forgot to mention is that I have to grind the beans very finely now at 1 or 2 setting to have the pressure I have for the shot. If I go any coarser the needle doesn't come up over 2-3 bars.

I also looked at changing the burr granularity but as mentioned in some videos my machine doesn't seem to have any internal burr changes for some strange reasons.