I call BS on that too, if the relief was set too high, a line would blow, not a seal. The seals are in places that simply can't be extruded and fail. Trash would have eaten the poop out of the pumps, and there would be metal particles everywhere.Hey Mr. Tazz! I have seen many talk about "case drain filters" that are suppose to be on the drive motors. I haven't seen anything that looks like that on this unit. The drives have 2 large lines and one small. The small hose on one side goes back into the tandem pump and the other side goes back into the control valve (I believe, don't hold me to that as I haven't been inside it for some time now due to waiting on a 2 new pump, but I digress) I've wondered if you or anyone has a way to remove all (or almost all) the hydro fluid from the drive motors short of removing them from the unit? I was told the 1st pump (that never worked) first, nothing wrong with it, then it was the seals were blown due to me having the pressure relief valve set too high, to finally, it's trashed due to contaminates so no warranty. Myself and several other threw the brown flag of BS on this company and their "diagnosis". So, before I put in my new (2nd) pump, I'd like to make sure I'm in good shape. During this ordeal everything was drained except the drive motors and the tilt cylinder. I didn't find any "contaminates" in the original pump and the only reason I changed it was I figured since I had to yank the engine for the tandem I'd save time and headaches and replace both. THAT'S what I get for thinking!
Sadly there is no real way to get all the oil out if you don't dismantle everything. The one thing you can try for the drive motors is to disengage the park brake and rotate the wheels, it will push all the fluid out it can.
The case drain filters are generally attached to the small lines you mettioned, your machine may be an early model that never had them fitted. My 743s never had them, the 753 came after that.