Hydraulic fluid in crank case

[Robertelee]

I have a M6800 I am getting hydraulic fluid in the engine oil what would cause this malfunction

 

[Motion]

Wow! Are you sure? How did you determine this condition? Is the crankcase being overfilled, are you short on hydraulic fluid? If the crankcase is over filling I wouldn't run the engine until draining out to the proper level. Is the tractor under warranty?

 

[PoTreeBoy]

We need to post a flow chart for this malady.
1. Are you sure it's hydraulic oil and not diesel fuel?

 

[Steve Neul]

Could be the seal where the hydraulic pump fits onto the engine.

 

[Bmyers]

 

[Russell King]

On my L185 it was a seal failure on the hydraulic pump power input shaft that fed hydraulic fluid into the engine crankcase.

Take pump off engine, replace seal, install pump, pour hydraulic fluid into the top opening of pump before you install the pipe. Change engine oil and start tractor. Done. Check engine oil obsessively for next few weeks until you’re sure that you have it fixed.

If the tractor is older and you’re not positive that the pump is original to tractor and there are serial number breaks for the seal, I suggest you order all the seal part numbers to be sure you get one that fits.

 

[North Idaho Wolfman]

Yep blown seal on the hydraulic pump, and FYI hydraulic oil in the engine won' t hurt it.
Just drain, change filter and refill with motor oil.

Now what can causes the hydraulic pump to blow seals is something causing back pressure or dead heading the pump.
Usual cause is something connected to the hydraulic system that is connected wrong or a clogged or malfunctioning relief valve.
Or it could be a simple cause of seal failure.

 

[wokndadog]

On my L185 it was a seal failure on the hydraulic pump power input shaft that fed hydraulic fluid into the engine crankcase.

Take pump off engine, replace seal, install pump, pour hydraulic fluid into the top opening of pump before you install the pipe. Change engine oil and start tractor. Done. Check engine oil obsessively for next few weeks until you’re sure that you have it fixed.

Hey Russell,
Thanks for this post, you may have just saved me a big headache on my L185.
However, I am looking at an exploded view of the pump assembly and am not seeing anything labeled as "Power Input Shaft" or "seals". Am I looking at the right thing? Here is the diagram, if you would, please verify I am on the right track and maybe where items are located (I assume between #1 and #6 positions of the diagram. Or is there an output shaft from the engine with a seal located between the pump and the mounting boss on the block, that isn't shown in this diagram?

Thanks in advance for your response.
Regards,
Gary

 

[North Idaho Wolfman]

This is what you need to look at:

 

[wokndadog]

Thanks Wolfman!