140G front wheel leak

[Spyros33]

A friend of mine recently bought a 140G AWD
Serial number 72V14969.
It has a leak on the front right wheel. I removed the full plug and it was way over filled. I removed the excessive oil, checked again after a week and it was full again.
My guess is that the hydraulic motor has a Bad seal and hydraulic oil leaks into the reduction gears.
Anyone has some schematics from the front hydraulic motor/ gears so i can get some idea before starting to Tear it down?

 

[Nige]

Spyros you could be in for big problems identifying & locating parts.
The AWD version of the 140G is/was a Custom Shop attachment built on the same 72V Serial Number prefix machine as the rear-wheel drive only 140G.
Take a look at all the 3Z & 1Q numbers on Pages 3/4 in the attached Bill of materials for 72V14969. The fact that none of them are hyperlinked means there is no information in SIS regarding a parts breakdown for any of them. Almost all of them relate to the AWD attachmentfrom what I can see.
There is a Custom Shop Parts Manual SEBF0600 for those attachments. It can be purchased online from Cat Publications as a pdf download, CD, or paper.

 

[Spyros33]

Thanks Nige!
Turned out that there are no reduction gears. It is a piston type hydraulic motor so from what i see it is supposed to be full of oil. There are three hydraulic lines going inside the wheel hub, i removed them, two are operating the pistons and the third one flows freely inside the motor housing, so i guess it is return line for the exceeding oil
When i removed the motor shell the oring was broken so i guess it Just needs a new o-ring and it is good to go

 

[Nige]

Best of luck..! Fingers crossed that it works OK after the O-Ring replacement.

 

[Spyros33]

Nige you were right as allways. Cat dealer can't even find the front hydraulic transmission system.
The hydraulic motors are poclain, so no cat part numbers there. Guess i will have to find that o ring on the market.
A friend Who is a mechanic told me that if the hydraulic motor is damaged, there is too much oil flowing on the return line, so it blows the o ring or the seal.
Will have to install the new o ring and remove the return lines from the two sides to compare the flow.

 

[Nige]

That’s what I was trying to tell you. Your friend needs to get a copy of that Parts Manual I posted a reference to above sooner rather than later. It’s the only source that I know of finding parts information for the AWD system.