Took my pump loose

[marrt]

I wanted to send my variable displacement pump back to PT for testing since I have the engine out. I have a bunch of JIC plugs and caps. So, I power washed everything and started the process. I first tried to remove the rear PTO pumps since I wasn't sending these back. In the picture below, you can see my friend holding the rear pump assembly while using a wrench to loosen one of the bolts.

When first examining the connection between the two bolts and the variable displacement pump housing, I noticed a gasket. And, sure enough, when we loosened the pumps, some oil ran out. Given these pumps are held together by only two bolts, I can't believe this is a pressurized set up. Still, I'm bit confused as to why there would be any oil between the rear of the variable displacement pump and the PTO and steering pump assembly. Seems like this would be a simple connection.

 

[MossRoad]

Yeah, that's odd. Perhaps there is a seal around the shafts of both pumps (there pretty much has to be, right?) and they are trying to prevent any dirt from getting into either pump through the shaft ends, hence the gasket? More like a dirt seal than a fluid seal. I'm guessing it was a small amount of oil, correct? Probably wouldn't worry about it.

 

[J_J]

Each pump has it's own seal, and if there is oil in the pumps between, then one of them is leaking.

I supposed if both pumps were leaking, one pump could push fluid into the other.

 

[marrt]

I talked to Terry today and this is "case oil." Apparently, this is like a case drain designed to lubricate the coupler to the rear pump. Oil from this area returns to the reservoir. Pretty cool.

 

[MossRoad]

How does it get in there and how does it get back? Are there some ports inside there? Just curious. Seems like a good idea to keep things lubricated. Must not be any sort of pressure as there's only two bolts on the gasket.