That's how I had it hooked up for testing. Had the hoses taped to a beaker full of oil. I know some say anti-freeze but I'm on the side of light weight hydro oil all the way. This is the pump unit I have removed from the dump of a truck I harvested it from.
I did tear down the pump unit last night and removed pinion from motor shaft without any harm. Some sealant along with a simple o ring is what they use for motor shaft seal on pump housing. Order some orings from McMaster and should have them tomorrow. .09-.07 by 1/16 something like that for replacement.
And someone else asked about the dump of a truck I purchased, some pics before it went to "Harry's you pull it" salvage yard ,
Only problem was Harry wouldn't take it !!!! Lol. Axles seem to be ok, little notchey but they go round.
. I ended up going with remote locker axles and a 4x6 drive train anyway.