T4.75 Powerstar leaking hydraulic oil only while driving?

DieselMonk · May 29, 2020

My T4.75 Powerstar with EHSS is leaking hydraulic oil only while driving somewhere around the hydraulic oil filter. Can't see anything much else wrong. Cleaned the filter operated the loader and it seemed all good. Started to drive the tractor around and sure enough it's leaking oil again. I took the filter off and it was humming tight on there. I mean so tight, it crushed the filter trying to take it off after 15 mins. The filter itself has no rust of any kind and the seal is not cracked or anything. The oil ring however feels kind of hard. The filter was changed 2 years ago and only has 100hrs on it. Not sure what to think unless the filter was put on too tight and crushed the seal? I guess I have to wait until I get a new filter installed and see if it is still leaking after that. The leak was so bad, that you could see trails where I went and where the tractor was parked there is a puddle. Pulled the dipstick and it was bone dry. I am guessing I've lost about 7 or 8 quarts or so.

Question is: Can a hydraulic oil filter leak oil out of the seal only while the tractor is driven?

tractorsam · May 30, 2020

The first thing that comes to my mind is that perhaps youæ±*e losing the oil from the hydraulic shuttle. Does it make any difference in forward or reverse? If your problem persists after the installation of a new filter (I have known filters leak but not at that kind of age) I would try a few things. Will it leak with the transmission in neutral but the shuttle engaged? If not youå€¤l need to come up with a safe way of locating the leak.

DieselMonk · May 31, 2020

Dunno yet. I went and got the hydraulic filter yesterday morning. Put that filter on the tractor and ran it stationary (it was raining yesterday) in the barn. It wasn't leaking, with the gear shifter in neutral and the EHSS in forward or reverse.. I have to wait for either this afternoon or tomorrow and take the tractor for a spin.
I've changed my share of filters and with all the gear around the lot, I've seen some things... but this... I haven't seen yet.

DieselMonk · May 31, 2020

Good news and bad news. The good news is that the hydraulic filter isn't leaking anymore. The bad news is, I have now another leak from the hydraulic pump to the flex line almost right above. I guess that came from trying to tighten things up on Friday. Aaaargh!