Quick Mill QM67: Brew gauge stuck over 16 bar

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by jinjabred »

Howdy folks! I'm having some troubles with my old QM67. I noticed awhile back that my brew pressure (according to the gauge on panel) was slowly rising... sometimes around 16 bar when pulling shots. I tried to adjust my expansion valve using the blind basket and it didn't seem to make a difference. I then noticed that my brew pressure gauge had gone all the way up to the bottom of the stop and got stuck. I decided to purchase a new expansion valve and gauge and figured I would be ok. Upon replacement I had the clear plastic tubing from the vibratory pump rupture after it was warming up the first time. After replacement of the tubing I thought I was in business, but I have another pegged out gauge. I'm a little confused at this point. I'm thinking the safety valve has to be stuck for that much pressure to accumulate and possible solenoid valve stuck open between the boilers??? Anyone ever had an issue similar to this?

Team HB

#2: Post by JRising »

The expansion valve is the safety valve for that circuit. The other safety valve is for the steam circuit.
What did you set the new expansion valve to? Something around 12 or 13 bars is high enough...

In order for the brew boiler's expansion pressure to blow the pump's hose(and to register on the gauge that reads before the check), wouldn't it have to be passing a check valve in the wrong direction? Also check that check valve, though it's not part of the safety issue, it's kinda good that a teflon hose blew rather than something brass.

I can't offer any more advice without knowing why your new expansion valve wasn't functioning, but check if it's seized or something.

jinjabred (original poster)

#3: Post by jinjabred (original poster) »


Thanks for the reply. That clarified a lot for me. I'm pretty sure I know what my problem is. I will report back if I get it fixed. :D

Team HB

#4: Post by JRising »

jinjabred wrote:Jrise,
I'm pretty sure I know what my problem is.
Check valve was removed, cleaned and reinstalled backward?

jinjabred (original poster)

#5: Post by jinjabred (original poster) »

No. When I replaced the Expansion valve I torqued the bypass fitting that goes back to reservoir. In my mind, I thought, "that may get close to the internals" but I shrugged it off. I should have listened to my inital thoughts. I think it was jamming the valve. I'm waiting on the new gauge to verify that the problem was resolved.

jinjabred (original poster)

#6: Post by jinjabred (original poster) »

So my problem has been resolved! I could see where the fitting was pressing into the spring in the pressure relief valve. I installed the new gauge, adjusted the valve, and am pulling some great shots! I'm going to go ahead and do a little more service on the E61 next. Thanks for the help!