Question about how my open center FEL valve with power beyond

   / Question about how my open center FEL valve with power beyond #21  
Where do you typically find that main system relief valve located on tractors? Is it usually adjustable?
On the kubotas I have worked on its under the right foot floorboard by the hydraulic filter and "manifold" block.

Its just a hex-plug....with a spring and ball. And only adjustable by adding a shim under the spring to make the opening of the ball a little stiffer....IE more pressure
 
   / Question about how my open center FEL valve with power beyond #22  
Where do you typically find that main system relief valve located on tractors? Is it usually adjustable?
I do not believe there is a “standard” location or adjustment style for relief valves on tractors. They should be the first valve from the pump but can be in a block located by transmission housing, can be in the FEL valve. Might be screw adjust or might be shim adjust.
 
   / Question about how my open center FEL valve with power beyond #23  
Where do you typically find that main system relief valve located on tractors? Is it usually adjustable?
On my Massy Ferguson GC 1715 it mounted just after pump on the hydrostatic transmission... And yes it unlike Kubota (using shims) it's a threaded screw type adjusting assembly...

Only way to tell what you really have is probably by having shop manual....Or at lease the proper page from shop manual...
 
   / Question about how my open center FEL valve with power beyond #24  
I'm confused. It sounds like you are saying the pressure can be double of what the pump is supplying. That can't be right. If the pump can only supply, for example, 2000 PSI, then it is not possible to get 4000 PSI, right? Am I wrong? I think I am misunderstanding you.
Thanks,
Eric
Yes, it can with a positive displacement pump with no pressure controls built in. More than likely as others have said it will be some other form of mechanical failure before it reaches extreme.
May years ago (35 plus years) in a hydraulic class the teacher said “every hydraulic system has a relief”. Of course he stumped many in the class cuz everyone knows all hyd systems have a relief valve, right?……..but wait, he didn’t say “ valve”.
His point was every hyd system will relieve itself to the weakest part in the system, might be a hose, tubing, cylinder, pump shaft or housing. He said make sure it’s relieving in a valve and not something to blow up in your face.
Hydraulics itself has no power on its own, hydraulics is only a means to transfer energy from one power source to the workload.
 
   / Question about how my open center FEL valve with power beyond #25  
Hydraulics itself has no power on its own, hydraulics is only a means to transfer energy from one power source to the workload.

You guys are really confusing me! Some guys say that a pump does not produce pressure and now you're telling me hydraulics has not power. So where the hell does the power come from?:)
(Preparing for lecture)
 
   / Question about how my open center FEL valve with power beyond #26  
Hydraulics itself has no power on its own, hydraulics is only a means to transfer energy from one power source to the workload.

You guys are really confusing me! Some guys say that a pump does not produce pressure and now you're telling me hydraulics has not power. So where the hell does the power come from?:)
(Preparing for lecture)
The engine😉

The hydraulic fluid just transfers the power of the engine.

And pumps just move fluid. The pressure is made by something resisting that fluid movement.

In a positive displacement pump like 99% of our tractors have.....it don't matter if it's trying to lift 5# or 5000#. The pump is still going to move the same amount of fluid one way or another. But the pressure is created by whatever is resisting that fluids movement
 
 
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