I will start by saying, I have searched this forum with no luck and googled it and no luck.

I rebuild these suspension compressors and replace or repair most components on them, but 1 fault has me baffled. High Pressure Exhaust Valve Vent Fault. Has anyone managed to fix this issue? If so, how? This fault comes after a rebuilt in every other way compressor (happens once in a blue moon) where they go up just fine, but then only the rear comes down on my test vehicle. It definitely isn't the vehicle at fault as I have the 1 I rebuilt for it on it which always gets plugged back in afterwards and the suspension works perfectly.

I actually have 1 compressor with the high pressure valve stuck open and a couple with it stuck closed. But you can hear the actuators clicking to open and close.

Thank you.