6310 hyd Proublems

I?ve got a 6310 cab I?m having trouble with Hydrolics pumping full stroke almost all the time (2900 psi) but while using it and pushing the brakes it?ll quit and go down to stand by pressure but the loader wont work like that but everything else does like it should only using only the pressure it needs but won?t raise loader with anything on it. Press the brake pedals and pressure goes up to 2900 psi until you press the brakes a few times then it goes to stand by. I checked rockshaft valve for cracks and priority valve and don?t see anything like that. I know it?s a load sense system but when it?s a standby doesn?t seem that there?s barely anything going to loader valve until you push the brakes and it goes to full stroke then everything works but seems to get a little warm on the back of the Hydrolics. Anyone have any ideas or had this problem? And yes the little dime valves or what ever the right name for them is are in there checked that to be sure. Thanks if anyone can help.

My knowledge of later model JD tractors after '92 is very limited. Maybe someone will reply & give you some help.

Is the loader valve a part of the "stack" with the inlet priority valve, or separate?

Sounds to me like the brake valve has an internal problem, and the loader valve plumbing isn't set up correctly, or something has failed in the loader valve.

It?s a mid mount valve JD and has a power beyond block that goes to the mid mount both new from Deere. I can unhook the lines going to the valve and it?ll do the same thing. It had been like this for awhile but didn?t know what was going on until the loader was installed. Dealer says it?s hooked up right.

Is it a JD power beyond? I fought an aftermarket (and the sales dept) with a poorly made valve....the porting for load sense was not allowing the pump to "see" the demand from the loader valve.
Your dealer should be a lot more knowledgable on a tractor this age I am afraid.

So even before the power beyond block and loader valve were installed the system wouldn't go into standby unless you tapped the brake pedal, correct?

And the second issue is that the loader valve isn't sending a "load sense" signal to the pump controller, right?

If that's correct, I'd start with the high standby pressure issue, maybe even put it back the way it was before the power beyond and loader valve were installed for the time being.

The brake valves are known to leak internally, and cause the problem you are seeing. Some time ago, I dealt with one that acted just like yours. Took the valve apart and found a cut/torn o-ring. Thought that would sold the problem. Nope. Wound up replacing the brake valve.

There's two load sense lines that run from the steering pedestal to the inlet priority valve... one from the steering valve, and one from the brake valve. You could check for pressure/flow in the brake load sense line... should be no pressure and no flow unless the brake pedal is mashed down. If there IS pressure/flow in that line WITHOUT the brake pedal(s) depressed, the brake valve is leaking internally and needs to be adjusted or repaired or replaced.

Another thing to check... what is the pressure in the line to the pump controller when the pump should be out of stroke, but isn't? Does the engine ever crank HARD because the pump is "in stroke" during cranking?

Once you get that part of the system straightened out, then move on to figuring out why the loader valve isn't sending a "stroke' signal to the pump controller.

Yeah both power beyond and mid mont are JD

Yeah Engine does crank hard when it?s cold unless you have it plugged up you can forget it it won?t crank fast enough to fire and doesn?t really have to be that cold just low 40?s at night warmer in the morning won?t do it, even idles slower when it?s like that. Now the two load sense lines you talked about can I plug a gauge in on the quick connects for ether one of those or do I have to T into the line to check those?

There's no test port to easily read the pressure in the load sense line from the brake valve.