950F transmission trouble shooting


1992 Loader, trans cooler failed, coolant got into transmission, they bypassed the cooler, then overheated, and failed, trans was rebuild, lots of clutch material in filter and screen, no amount of metal. Converter was checked for any wear none found, all seals replaced, new pump installed.

Pump pressure at 100 psi (310 min), converter inlet at 30 psi (130 max), converter outlet at 0 psi, speed clutch at 20 psi, directional clutch at 20 psi, lubrication oil at 15 psi (correct).

Trouble shooting suggests Modulation Relief Valve out of adjustment, valve is not adjustable, I have added shims to the load piston and it does raise the pump pressure, only to 150 psi, (275 at high idle).

Next steps?

-replace Modulation Relief Valve, or Hydraulic Control Valve group

-can the torque converter be air locked?

-can the torque converter be leaking so much that all pressure is lost?

-can the Hyd control valve be leaking so much?

-should I change oil from 10W to 15W40?