Hydraulics lifter assembly KAMA TS254C

[lakespirit]

The gear box is under the hydraulic fliud tank that has the rear end. The hyd. fluid must be getting through the oil seal through the bearings that hold the shaft from drive to the rear hyd pump.

 

[greg_g]

The "gear box" to which you refer is actually the rear differential housing. You don't put hydraulic fluid into the differential housing. Hydraulic fluid goes into the sump through a fill/vent behind the seat, gear oil goes into the differential housing through a fill hole in front of the seat. Please clarify what you're putting where.

It sounds like the seal that you're referring to is the aux PTO shaft seal. It seals gear oil into the differential housing, not hydraulic fluid. Please clarify what's leaking from where; hydraulic fluid from the PTO pump, or gear oil from the differential housing.

//greg//

 

[lakespirit]

I am losing hydraulic oil into the rear diff, but can't figure out what's going on with the seal. It is the correct size as stated in the parts manual. The gear oil is now diluted quite substantially form the hydraulic oild leaking into it. If I understand you, The shaft that drives the hydrualic oil pump is the PTO aux shaft?

 

[greg_g]

No reason to believe your 254 is configured any different than my 354, so yes. The permanently mounted rear hydraulic pump is indeed driven by the aux PTO shaft. But it's only a mechanical connection. There should be no reason that hydraulic fluid is getting into your rear differential housing that way. What I don't know is if your hydraulic reservoir under the seat is a one piece sump. If yes, there's no way for hydraulic fluid to get in that way either. If no, you'd have to remove the seat, then remove the sump to determine if that might be the source of the leak. Obviously, drain out all the hydraulic fluid first.

//greg//

 

[lakespirit]

I've had this apart for some time now. There are two bolts and two studs on bottom of resevoir sealed with o-rings. They don't leak, I have replaced them and filled with fluid and allowed to sit for a couple days. It's only when I put it back together and run the engine that the fluid gets into the rear differential.

 

[Bob Rooks]

The auxilliary PTO shaft goes straight through the differential housing, through a bearing and out the back. There is no internal seal and when the hydraulic pump blows it's seal it pumps oil around the blown seal through the bearing and into the differential housing, thus filling the differential with hydraulic oil.
The correct positioning of the lip seal in the hydraulic pump will have the face of the seal (part number side) facing out, spring and lip facing in to the pump. Seal face should be flush with the pump housing.

 

[lakespirit]

Anyone know how to adjust the pressures inside the hyd sump? Since I have replaced my seal with the size recommended and stil am leaking (when not flooding) into the rear diff, should I go a size smaller on the I.D.?

 

[greg_g]

There is no internal pressure to adjust, the sump is little more than a holding/cooling reservoir. But there's something about this problem of yours that doesn't compute. I'm guessing there's some part of this story that you're not telling us.

And every seal you need on that tractor is specified in the TaiShan parts manual. Is that what you mean by "the recommended seal"? Or have you stuck something else in there. If push comes to shove, I've still got an entire set that should have every grease/oil seal and O-ring you'd ever need for that tractor.

//greg//

 

[greg_g]

when the hydraulic pump blows it's seal it pumps oil around the blown seal through the bearing and into the differential housing, thus filling the differential with hydraulic oil.

No, it shouldn't. I say shouldn't, because there's an oil seal where the aux PTO shaft passes through the housing. Maybe even two, but I don't have my books anymore. So even if the PTO pump seal is leaking hydraulic fluid, it still shouldn't get past the aux shaft seal to mix with the gear oil.

There's something else going on here that we haven't been told yet.

//greg//

 

[Bob Rooks]

The auxilliary PTO shaft is high enough in the differential housing that it doesn't need a seal, and if perchance there was a seal there it would be facing such as to keep oil IN the housing, thus allowing pressurized oil to pass freely into the housing. This is the same setup that is on my dozer and I know that it will fill the housing with hydraulic oil in a heartbeat. I speculate that there is a serious restriction on the pressure side of the pump causing the seal to blow, quite possibly the internal "figure-8" seals are blown or there is too much clearance between the gears and end plates. Also, the end plate bearings could be bad/oversized through wear.