The spec sheet says the pressure should be min-55 max-75 is this full throttle or low idle? If I do a stall test should the pressure be higher at full throttle?
Hi Jonathan, it seems the CAT team is somehow quiet right now. I'm definitely not a CAT expert, however from my experience in powershift transmissions other brands I'd say: The 55-75 PSI inlet converter is spec at low idle, might go up to 150 PSI at high idle. Do not measure in stall condition as this might fool you completely. Internal forces/flows might create crazy pressures at inlet port. Again, I never worked on a CAT tranny, but torque converters usually react in a similar way. Hope, the CAT experts can confirm.
Are you talking converter inlet pressure or outlet pressure.? I assume outlet pressure based on the numbers you quoted. Inlet pressure aka P3 is usually measured at high idle in neutral, outlet pressure is measured with the converter in a stall condition against the brakes or an immovable object and the highest possible gear selected in the transmission.
Outlet pressure. Pressure is 80psi at high idle, and 5-10psi at low idle. This is the same for neutral and stalled.
Is it possible that the torque converter is not getting enough oil even though the pressures are within spec? The tractor seems to have very low power and I suspect the torque converter is causing the problems. If I run the loader hard for a few minutes I can see bubbles in the sight glass of the transmission.
Your reading on torque converter outlet is about what I have always experienced. Bubbles in the oil indicate air getting into the system usually on the suction side of the transmission pump. There will be a suction screen in the bottom of the transmission that will be part of the suction piping usually. I would expect some kind of hose as well with double clamps on each end. When the hose gets hard as a rock is when they tend to be able to suck air. Sometimes all you have to do is tighten the clamps.
Thanks, I'll check that out.