7341 close to total hydraulic failure.

We have at work a 98' 7341 that have as long as I've worked here not been able to lift the frontloader or anything attached to the rear... This is mighty irritating- as we mostly use the tractor to remove snow from our road with a rear mounted snowblower facing backwards. We cant even turn the funnel around at a decent speed

If we rev up the engine a bit we might be able to lift the front loader slowly- but there cant be any strain on the system...

I've come to belive that there is an overpressure valve in the hydraulic system that will open if the pressure is to high- and I fear that it might be stuck in an open position- thus letting all the oil return to the reservoir. Am I on the right track here?

We have tried all the usual remedies... changing oil... filters... pump... etc... last time we changed oil we found something closely resembling a staple in the filter...

My question is... Where do I find this pressure valve and how do I get to it?

Is there any other possibilities?

- Iceman

on the old models it was located underneath the rear axles, close to the pump. On the new models with engine mounted oil pump, i cant tell you where it would be, probably at the point where the pressure line enters the transmission.
It could also be a blown O-ring inbetween some oil line towards your valve blocks.

If you've tried the pump it sounds like a relief valve problem. There may be more than one !! There is almost certainly one on the side of the loader spool valve. If the pipe from the pump goes straight to this, thats's the place to start. If it goes to a hydraulic trailer brake valve ,there is probably a relief valve there also. The original one could still be in the round plate under the rear of the back axle. Good Luck.