97 Kubota L2500 hydraulic fluid filling motor

[3tike]

Hi I have a 3cylinder diesel that got filled up with trans hydraulic oil ( this tractor did it to its self while I was driving it ) so first thing after changing fluids is replace hydraulic pump shaft seal the same thing happened again within minutes , ordered new hyd pump installed same thing happened , installed gauge between pump and relief valve when idleing with no hydraulics being used reads 0 three point lifting implement 750 psi max out fel 2250 psi turn steering wheel to left 750 psi smooth turn steering to right 250 psi hard to turn at this point no fluid being pumped into motor shut off motor returned next day , start doing same thing with hydraulics turning steering wheel and 3pt ect. same results , than all of a sudden all hydraulics stop working and gauge still reads o and the motor is filling with hyd fluid I know this may be hard to follow but anyone have an idea where this fluid is getting into motor and what is causing it ? thanks 3 tike

 

[J_J]

My best guess would be the hyd pump shaft seal, but you said you replaced it, but was there a groove worn in the shaft, if so, it would still leak.

You said you also installed a new pump, but did you do anything to deadhead the pump. Could have blown a seal.

I believe I would take the new pump in for a bench test to verify whether it is still good or bad.

You might be able to get away with a deadhead situation at low engine rpm, because the relief valve can take care of a few GPM, but at high engine rpm, deadheading the pump can blow just about anything, such as hoses, valves, pump casing, etc.

 

[3tike]

My best guess would be the hyd pump shaft seal, but you said you replaced it, but was there a groove worn in the shaft, if so, it would still leak.

You said you also installed a new pump, but did you do anything to deadhead the pump. Could have blown a seal.

I believe I would take the new pump in for a bench test to verify whether it is still good or bad.

You might be able to get away with a deadhead situation at low engine rpm, because the relief valve can take care of a few GPM, but at high engine rpm, deadheading the pump can blow just about anything, such as hoses, valves, pump casing, etc.

The original seal i replaced looked fine and there were no groves in shaft , replaced with new seal and that lookes fine on original pump , brand new pump had new seal , I was just pulling a 72 inch mower deck when filled motor with oil , no reason to think dead headed hyd system been mowing with that for years , today when filled engine it was at idle with no implements , I am thinking of shimming pump off engine block an 1/8 inch and seeing if pumping oil out of shaft seal , but really the seals on shaft of both pumps dont look damaged , is there another source for hydraulic oil entering engine ?

 

[3tike]

The original seal i replaced looked fine and there were no groves in shaft , replaced with new seal and that lookes fine on original pump , brand new pump had new seal , I was just pulling a 72 inch mower deck when filled motor with oil , no reason to think dead headed hyd system been mowing with that for years , today when filled engine it was at idle with no implements , I am thinking of shimming pump off engine block an 1/8 inch and seeing if pumping oil out of shaft seal , but really the seals on shaft of both pumps dont look damaged , is there another source for hydraulic oil entering engine ?

so , the oil was getting into motor through front seal , inspected relief valve , priority valve , and power steering relief valve , all were fine , isolated power steering out of the hydraulic circuit by looping a hydraulic line from pressure to tank on priority valve and this stopped the hydraulic fluid from filling motor , so I have a power steering problem , thanks for reading hope this helps someone some time 3tike