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SMG Pressure Relief Valve?
My M5 has been inoperable since February. The cause was due to the pressure sensor exploding out of its socket. The plastic portion of the sensor were in pieces. The wire stripped out of the harness of the temp sensor. So I replaced both sensors and a new PLCD and attached it to a spare block I had .
For the past four months, I have been dealing with low hydraulic pressure. Initially after the reassembling everything , the pressure remained at 1 bar. I followed Jcolleys procedure on priming the pump and repeated it numerous times. I must have gone through a dozen bottles of Chf11s!
The pressure finally exceeded the threshold since the shifter light came on and was able to switch gears. I thought I was golden, I hooked up ISTA and ran the bleeding procedure. Went for a victory cigar break, waited an ample amount of time to check on the process. ISTA still showed the hour glass indicating it was still processing, but no reaction from the car nor can I hear anything. Restarted the procedure and same issue.
Ordered replacement relay and rechecked the fuse, but without success, the hydra pump motor relay does not “click” after reinserting the relay as it should have. Same results from using DIS.
I then tried INPA, activated the pump motor and immediate swapped laptops and started bleed procedure via DIS. I can hear the slave and clutch valve working, but for some reason pump wont run by itself, which results in a clutch deviation after the procedure, additionally I got a pressure under shoot.
I looked at drained hydraulic fluid from the reservoir and noticed aluminum shards. I wanted to check the gear pump for obstruction. Upon disassembly I found no evidence of containments however the thrust plates and seal gaskets were not great. The plates had burn marks which led me to believe that the pump got real hot since I was trying to prime the hell out of it. I blew high pressure air at the gear pump, and the aluminum block where I had removed the two sensors and valve, accumulator the relief valve retention bolt and shot it with blow gun and the relief valve came out.
Does anyone know how relief valve needs to be positioned/pretensioned or any specific procedures? Also does the block look damaged, it appears to have a small gash or that where the relieve valve pin suppose to sit?