Machine is a OROPS 260, no quick tach, or anything, bare bones, I can’t provide the serial because it’s illegible. Here’s the back story on the machine, I bought it, seemed to drive fine but once I got it home and started using it more it stopped pulling on the left side. Pressure on be hydrostatic pump checked out good so I removed be drive motor and found seals were deteriorated. Replaced all them installed it back and let the machine run some while I checked for leaks. Put the cab down and drove it 20’ and it lost full power on the left side, backed up and saw a trail of oil so I cut it off. Lifted the cab and cranked it and within seconds oil starts gushing from the top cover of the left hydro(where the swash plate comes through) I replaced the seals not long ago and it seems like it has a lot of pressure in there and want to know where to start checking. I pulled the hydraulic pump off and the seals in between are good.
Either a hydrostatic pump case drain pressure test or flow test should be performed. Do you have the manual TM1780? If not I suggest you get one. It spells out how to do the procedures I mentioned.
Yes, I do have the manual. But I wasn’t sure what to test first. It starts pouring fluid before taking the parking brake off or touching the steer lever. Will excessive case drain from the hydraulic pump cause pressure in the hydrostatic pump that it’s connected to?
Not likely. The shaft seal on the hydraulic pump should be connected to the low pressure side of the hydraulic pump. I thought you said the seals were fine in the hydraulic pump? That leaking lever shaft seal you have will affect the case drain reading.
Well I decided to pull it apart, figured instead of spending more money on hoses and fittings to do the case drain test that the issue was most likely the pump anyways. After tearing it down I found all the slippers are worn out and the cage that holds them is broken. So now time to source parts and put it back together….again
The seals where the hydraulic pump mates to the hydrostatic pump were good. The excessive pressure blew out the top seal, I pulled the cover, fixed the seal and once the drive pump got under a load it did it again
Yep, that will fail a case drain test. What shape is the other hydrostatic pump in? Better be ready to spend money on both pumps and drive motors, as well as a system clean up.
I haven’t pulled the other side apart yet but I suppose I will while everything’s apart