7745 slow hydraulics

Hello everyone.

I've been reading several posts on this forum about hydraulics. Very informative... Maybe someone can help me with my problem.

I have a 7745. One day, while moving dirt with a front loader (Quicke 650 I think), I lost all power to the hydraulics. I was able to remove the bucket on the front loader, and I drove to the barn where I discovered the ever so hidden magnetic filter. It was full of metal dust. The filter over it was broken in one place. The hydraulic pump itself was worn abit, so I changed both the filter over the magnetic filter and the pump. I also changed the oil (from 80/90 to universal oil).

Results: the hydraulic lift in the back seems to be working fine again, but the (empty) front loader is still slow. I have to rev up the motor to 1500 rpm for it to go at a decent speed. There's also a buzz sound comming from the back of the tractor that disappears when I actuate one of the hydraulics. I haven't tried moving a heavy load yet.

Is there something still wrong with my tractor or is all this normal? Thanks for the help.

Jonathan

the flip lever on the vertical part of the cab floor, before the seat elevaton, adjusts the oil flow. try twisting it fully right or fully left. (cant remember which side is what)

Sounds like there is some kind of a restriction in the loader circuit somewhere. Do you have quick couplers between the loader and tractor ? My brother had a problem with his dumptrailer, we changed the tailgate cylinders for bigger ones (even though they had 500kg overcapactiy) and still problems. In the end it turned out to be a worn antileak valve in the ISO coupler, when coupled the two pins touch each other to open the antidrip valves. When worn or damaged, one valve can close under pressure.

Thanks for the help. If you like happy endings, read on...

I tried looking for the lever you wrote about. Do you mean the lever which controls the PTO speed (from 500 to 1000)? That was the only lever I could find.

At any rate, I tried moving a bail of silage with the back loader, but the hydraulics there were too week. That meant something was wrong with the entire hydraulics system. A friend came by and helped me out a bit. I found out about pressure releaf valves. In addition to the one beside the hydraulic pump (inside), there is a pressure relief valve on the batterie which controls all hydraulics. We took both off and it turned out the external one had just a little tiny bit of dirt/grass which prvented the valve from closing. The hydraulic system couldn't build up the necessary pressure for running implements. Now, the hydraulic system works better than ever. The only irritant is that I probably ddin't need to change the pump, and instead of waiting for parts for over 10 days, I could have fixed my tractor in under 20 minutes.

Ah well....