560 IHC hydraulic not cancelling when hot

We replaced TA and both hydraulic pumps last winter.This tractor has a fast hitch.Everything worked fine in cold weather on manure spreader.When we started using it more the air temperature was higher and as the tractor warmed up the hydraulic valves would not cancel if used.Sometimes slowing engine down would cancel them.If we run the tractor a little longer(warm it up more)we have to shut engine off to cancel remote valves.We have been unable to determine which valve is causing the problem.When tractor is warmed up(takes 1-3 hours)using any remote or hit a bump(asuming hydra-touch linkage actuates valve).Has anyone had this problem and been able to solve it?Thanks

Dunno, just off the top of my head and trying to help ya think this out.

Could someone have cranked up the latches somewhere along the line to compensate for the weak(er) pump?

Does the 560 even have latch adjusters on the remotes?

Allan

I think what you are saying is that system stays on demand, even though valve levers come back to neutral. This is caused by more oil leaking past the worn lands in your valves than what can get through the orfice in the regulator valve. If indeed the levers will not come back to neutral that would be something I have not seen and would be only caused by binding of the valve spools. Torque on the bolts that hold valve body together is only 20 ft pounds so as valves will not bind. That being said though, I would take the four bolt cover off regulator valves assembly, remove the screwdriver headed orfice screen. It will no doubt be plugged , collapsed etc. If the orfice has a small roll pin holding a check ball in place you may have to buy a new orfice as the orfice hole gets peened shut over time and that seat is hardened so almost impossible to enlarge which is what I am about to tell you to do. I would drill it out to about .040 for starter and see if that takes care of the problem as this will compensate for the wear in valves. Making it too large may cause you to not be able to build pressure and will also lose some of your flow. Most likely it is the hitch valve giving the problem . Note, heavy spring under that cover, I use a couple longer bolts to install cover. Put on new gasket, new o-ring on regulator piston also. It is possible your double to single adjustments on other valves have a broken or bent pin allowing it to turn too far but this will usually show up before warming up also. Good luck.