Hydraulic oil in engine oil pan

Tegan

New member

Equipment
L3650
Oct 25, 2022
6
2
3
Massachusetts
L3650 gst has hydraulic oil in engine oil pan and blowing out breather.

Steers, shifts, bucket and three point all working. Once one gal of oil blows through breather. Hydraulics then start to act up.

Is rear main seal shot, this is a glide shift transmission.

Making plans to break machine in two, now. Parts tools to have on hand, things to do not to do.
Appreciate any input. Tegan
 

rbargeron

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L5450, L48, L3250, L345 never enough attachments
Jul 6, 2015
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May be good not to take it apart until more testing locates the root cause of trans fluid leaking into the engine. Very UNLIKELY to be caused by the engine's rear main seal. It's more likely a problem in the hydraulic system.

The L3650GST is basically a regular gear-type tractor but the gears are shifted by a set of hydraulic valves instead of a stick shift. If hydraulic oil is leaking into the engine, one suspect might be the seals at the front of the main hydraulic pump (on side of engine). The pump is apparently making pressure ok - but some oil may be leaking forward into the engine's front gear case, eventually raising the pan level until it's coming out the breather from crankcase pressure.

Maybe others will chime in with more experience chasing pump seal leakage. Take care, Dick B.
 
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TheOldHokie

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Apr 6, 2021
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L3650 gst has hydraulic oil in engine oil pan and blowing out breather.

Steers, shifts, bucket and three point all working. Once one gal of oil blows through breather. Hydraulics then start to act up.

Is rear main seal shot, this is a glide shift transmission.

Making plans to break machine in two, now. Parts tools to have on hand, things to do not to do.
Appreciate any input. Tegan
Most likely pump input shaft seal. No need to split the tractor for that.

Dan
 
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Tegan

New member

Equipment
L3650
Oct 25, 2022
6
2
3
Massachusetts
Sure do hope this solves the problem! Wasn’t looking forward to splitting the tractor.

I rebuilt the pump a year and a half ago but didn’t do this seal. Dang!!
Thanks much T
Pulled pump, removed seal. Real PIA cleaning out the groves. Is there any advise is pressing the new seal in so that it seats properly below where snap ring goes?
 

Pau7220

Well-known member

Equipment
L3650 GST, Landpride TL250 FEL w/ Piranha, 6' King Kutter, GM1084R Finish
Aug 1, 2017
785
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Scranton, PA
You can use a deep well socket (slightly smaller than the outer diameter of the seal) and a very small hammer. Shouldn’t take much force at all.
 
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Tegan

New member

Equipment
L3650
Oct 25, 2022
6
2
3
Massachusetts
You can use a deep well socket (slightly smaller than the outer diameter of the seal) and a very small hammer. Shouldn’t take much force at all.
I was thinking about putting the seal in the freezer. Maybe put a light bulb on the housing for awhile before installing. (Shrink seal and heat housing to help smooth install.)
 

Tegan

New member

Equipment
L3650
Oct 25, 2022
6
2
3
Massachusetts
I was thinking about putting the seal in the freezer. Maybe put a light bulb on the housing for awhile before installing. (Shrink seal and heat housing to help smooth install.)
Well found what the issue was that was making seal installation difficult. When I removed the old seal. It came apart on a horizontal plan, leaving the internal metal of the seal in place and after digging out the last of the seal with a pick, the metal case popped out and installing the new seal was a cinch.
 
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