950F trouble shooting

[wrightdj]

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 cooler, lines flushed, new pump installed.

Pump pressure at 100 psi (needs 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?

 

[Mark250]

hi
SERIAL NUMBER PLEASE
Who rebuilt the transmission?
Was the control valve cleaned properly as there a number or orifices that can block.
the screened orifice in particular is easy to leave out or miss as it can fall out and get lost if you are unaware of it and will cause issues like you mention.
I would hound the person or company who rebuilt it, to fix it for you.
They are not rocket science to over haul and very rare to give trouble

 

[Nige]

100% what Mark said. There are so many little nooks & crannies in the control valve where debris from a clutch failure can end up, especially that little screened orifice that nobody who's never worked on before even realizes is a screen........ What holds the screen together is a plastic housing. If that housing's cracked it needs replacing. I show it as Part Number 9W-9831, price US$12 whatever Serial Number of 950F you have. However post your actual S/N just to make sure.

 

[wrightdj]

Thank you for your response Mark250 and Nige, serial # 7ZF00879, Trans # 8NE01285, ARR # 6Y7414, we were unable to find a replacement transmission at the time and I took on this job, Did find some plastic pieces when I disassembled, and was unaware of that screen, have ordered and will check tomorrow, if it is not there, will let you know how things turn out. Thanks again.

 

[Mark250]

Don't forget the 0 ring on the screen
mark

 

[Nige]

The 9W-9831 screen is correct for your machine. The O-ring is a 5H-8853.

 

[wrightdj]

Installed new part and everything is working properly, all pressure are within spec's.
Thank you for your help, very good web site will recommend and visit.

 

[Nige]

Always nice to hear a success story ........ so many times people just disappear and never come back with information regarding what actually fixed the problem.