CM871 oil pressure

[pearce trucking]

I replaced the oil filter today and pressure seemed to be restored, although it was 7-8 psi at 600 rpm idle. I put the new bypass valve back in and the pressure went back to zero. I figured out that I did have the correct (16mm) plug to hold the bypass valve in. So the loose bypass valve wasn't the issue. I bought a mechanical gauge and checked pressure at both the oil filter head and at the oil pressure sending unit. It was zero at both. I checked oil pressure with the mechanical gauge in my tripac motor. It immediately read 60 psi. So the mechanical gauge works. Tomorrow I'm going to pull the oil pump, disassemble it, and inspect.
Fingers crossed that the pump is just worn out and the dimes made it work harder and finished it off. We'll see.