I just replaced the o rings on the outer sleeve and drive spool to fix a leak on top of the tandem pump - the rear pump. I put the sleeve and spool back in how it's supposed to go, and the leak stopped but now the pump is making a whine noise, like it's starving for oil. The control lever attached to it works fine. I drained 5 gallons from the reservoir before I removed the spool, then put it back in when done. I thought it may be air in the system, but I drove it around for a good 20 minutes and that should be long enough to work it out. My next step is to pull the sleeve and spool again and make sure a piece of dirt didn't get in there, but I doubt it. Any suggestions? Could there still be air in the system causing this noise?
See if Case has a procedure for bleeding the pump.
The only bleed procedure is to engage the wheel motors, either in the air, or on the ground.
My skid steer calls for turning the engine over (not starting it) for about 15 to 20 seconds a few times to prime it.
My only thought is to make sure the spool sleeve is fully seated down. It has ports that that will be partially blocks if it's not fully seated.