My PP700 is only about 18 months old, dedicated water softener, and quality tap water. My house/line pressure is a little high (spec says about 30 psi) my line is about 50psi. For the first year I was getting great group pressure about 9 bars (had to lower the factory setting down to 9 with pump bypass screw because of high line pressure). I then decided to install a line pressure regulator for true 30ish psi, and now the machine won't pump higher than 6 bars with blind basket in.

The shots taste good but no where near 9 bar anymore regardless of bypass screw positions. Even returning the line pressure to 40-50 doesn't help. I don't know where the pressure loss would happen, I have cleaned the mushroom valve, check valves, solenoid and vacuum bleeder. The pump bypass plunger was damaged and after fixing the bypass plunger assembly still no change even when fully closed I should get max pressure. There is no leaking for constant dripping. I've also inspected the pump guts and re assembled, no scale, back to 6 bar max again. I'll try a different pressure gauge and see if that has failed. I leaning towards a new pressure gauge or pump. The machine has lived in my heated house the whole time (no frost storage).

Does 40-50psi damage the fluid-tech 50L/H pump? It didn't look damaged inside. I didn't break any parts inspecting and putting back together. Suggestions?

Maybe a leaking in the overpressure valve, which in your machine should be inside between the boilers, but you should see a flow of water in the drip tray.
Or maybe a steam boiler refill valve leaking , but you should to see an abnormal increasing pressure in the steam boiler.
Do you still have warranty?

sinner wrote: I then decided to install a line pressure regulator for true 30ish psi, and now the machine won't pump higher than 6 bars with blind basket in. The shots taste good but no where near 9 bar anymore regardless of bypass screw positions. Even returning the line pressure to 40-50 doesn't help.

Does 40-50psi damage the fluid-tech 50L/H pump? It didn't look damaged inside. I didn't break any parts inspecting and putting back together. Suggestions?

Did you try removing the line pressure regulator completely, if not try that?

40-50 psi will not damage the pump but takes you to the limits of pressure differential spec and bypass adjustment

Do you can read some pressure value in the gauge when the machine is in idle?

Giampiero wrote: Do you can read some pressure value in the gauge when the machine is in idle?

Yes the gauge will show the line pressure and does move up when the pump runs. With first setup (brand new) the pressure screw was very responsive up to 12-13bar, down to 9 or less.

DaveC wrote: Did you try removing the line pressure regulator completely, if not try that?

I can try removing it again, I know the added line pressure helps but doesn't get past 6ish bar.

Giampiero wrote: Maybe a leaking in the overpressure valve, which in your machine should be inside between the boilers, but you should see a flow of water in the drip tray. Or maybe a steam boiler refill valve leaking , but you should to see an abnormal increasing pressure in the steam boiler.
Do you still have warranty?

The overpressure valve had a little scale a few months ago, i removed it and flipped the seal pad, leads to the drip tray and it's not leaky idle or under pressure. The steam boiler was leaking from the vacuum/pressure valve, a new oring/cleaning fixed that, didn't help fix brew pressure. I'll watch the steam pressure during a cycle, I don't think it changes about 2.5bar. The 1 year warranty is expired.

If i wanted to test the pump off the machine, can you just run the output directly to different gauge? Are the flex lines metric, what size?

I removed the pressure regulator on the supply line, the static pressure is about 4 bars, blind basket/brew pressure is now 7.5 bars so this pump is only adding about 3.5 bars of pressure. Also tried the bypass pump screw and 7.5 bars was the max. grr

sounds like either the balanced bypass is defective, or the pump has gone.

Installed a new pump, went to 14bar out of the box. Dialed it in to 9 so the gauge is good. This replacement fluid o tech pump has a bigger bypass screw/nut combo. The pro700 frame hole is too snug and it vibrates the frame when running. I'll have to tweak the pump position or make the frame hole bigger to eliminate the extra noise.

Don't know why the factory pump lost power so quickly (about a year). Apparently the extra line pressure must have warn the original pump too quickly. Anyways after the noise is fixed it'll be really fixed.

Thanks for the suggestions.

Aaorn