1994 753c drive motor issue

tonykoser · Oct 15, 2013

Ok call me stupid. Bought a loader from a family member on "his word" Told me it ran great had a very small hydraulic leak. I loaded it up and brought it home. First thing I did was to pull a full PM. found the hydraulics to be about a gallon low. Lifted up the cab and observed the right motor well to have lots of hydraulic oil, left side was dry Filled up all fluids and went to work. Noticed quickly that the right hydraulic motor, as I sit on the unit was overrunning the left. Also noticed that the left motor was very smooth all the way thru the range but the right motor had a noticeable jerk at about the half way point. All the loader hydraulics operate great. Plenty of lifting power. After a 30min run I lifted up the cab and noticed more oil in the right drive motor area. I took off the right motor cover and had my son operate the unit. I notice that there was oil coming out of the two hex caps on the face of the motor, assume this is a pressure relieve valve. I took the caps off and checked it all out. No issues there with the plunger, springs or caps. I replaced the O-rings, restarted the unit and noticed that about the time the right motor jerks at half speed oil squirts out. Everything sounds good. No noise from the hydraulic system. Need some help

Tazza · Oct 16, 2013

Behind the cap is the shuttle valve, as you have found, there is just a small O ring sealing them up. Is it still leaking out of this cap after you replaced the O ring?
I'd start by removing and cleaning the case drain filters. Trace back the case drain lines from the drive motors and look for an alloy canister. There should be two of them. Either replace them or open them and clean them out, see id that fixes the jerkyness.

tonykoser · Oct 19, 2013

Tazza said:
Behind the cap is the shuttle valve, as you have found, there is just a small O ring sealing them up. Is it still leaking out of this cap after you replaced the O ring?
I'd start by removing and cleaning the case drain filters. Trace back the case drain lines from the drive motors and look for an alloy canister. There should be two of them. Either replace them or open them and clean them out, see id that fixes the jerkyness.

ok thanks

tonykoser · Oct 30, 2013

Tazza said:
Behind the cap is the shuttle valve, as you have found, there is just a small O ring sealing them up. Is it still leaking out of this cap after you replaced the O ring?
I'd start by removing and cleaning the case drain filters. Trace back the case drain lines from the drive motors and look for an alloy canister. There should be two of them. Either replace them or open them and clean them out, see id that fixes the jerkyness.

replaced all filters in the hydraulic system. Right motor still jerks at half stick and leaks out the caps. Any other ideas out there