Oil & Fuel Odd Ford 641 hydraulic oil level issue.

bobsphotos · Dec 1, 2014

My new to me Ford 641 has a very odd hydraulic oil level issue. When I brought the tractor home I changed all the fluids and used UTF for the transmission, hydraulic reservoir, and rear end. After a couple of months of use I noticed that the hydraulic dipstick showed that the fluid level was very high. I drained it back down to the correct level. The tractor is in my friends shop so we can rebuild the motor and I decided to recheck the fluid levels. I pulled the side plug from the tranny and about 1 1/2 quarts of fluid came out. I pulled the side plug from the rear end and about 2 ounces came out. I checked the hydro dipstick and it is right at the top again. Is it possible that engine oil is sneaking out past the hydraulic pump drive gear and being pumped back into the hydro reservoir? Extra oil is coming from somewhere. After about 4 hours of use I have to add 2 quarts of oil. I know some of that is being used by the motor because it does blow blue smoke. I do need to add that it takes about 10 minutes for the air to get purged from the pump and wondering if it needs a rebuild.

Xfaxman · Dec 2, 2014

Does it have a front end loader on it?

Or a backhoe?

bobsphotos · Dec 3, 2014

Neither.
Bob

trmechapt · Dec 7, 2014

The hydraulic piston pump on the rear side of the engine is most likely the problem. The shaft seal is allowing the pump to pull engine oil past the seal and into the hyd. system. The shaft seal is a double seal and while the engine is off the tr. go ahead and rebuild the pump. There are a few special tools to remove and replace the valve ball seats though, so you may have to take it to someone who has the tools.
Gary

bobsphotos · Dec 19, 2014

Hey Gary,
I missed your comment since I haven't checked my post lately. The pump is apart and we found a trashed inside bearing and a badly scored wobble shaft. The parts have been ordered. Do you think this condition could result in as much as a couple of quarts of engine oil getting sucked into the hyd sump in a month?
Thanks,
Bob W

trmechapt · Dec 20, 2014

Yes. When I worked at the Ford Dealer in the 80s We installed a new pump on a 3400 Ford. There was something wrong with the housing and the needle bearing wouldn't stay in place. It let the shaft move around and it pulled enough oil out of the engine to lock up the engine. So that could easily pump 2 qts. in a month.
Gary