control valve question

[estodd]

Hey everybody,
I am still trying to figure out why my Kabota L245 three point lift is not working.
Does anyone know if the control valve which regulates the lowering speed of the lift arms has any effect on lifting.
My lift was working fine but the speed control was not working. It made no difference where I set it the arms it would fall very fast.
Now my lift does not work and I am just wondering if that valve could have anything to do with it.
I want to fix this thing but I am trying to weed out what to try and what not to try or at least start with the simple things first.
Thanks in advance everyone.
Have a great day!

 

[TedLaRue]

estodd,

You may have two separate problems.

On my John Deere, fluid flows through that rate-of-drop valve in both directions.

When lowering the hitch, fluid escapes from the cylinder through that rate-of-drop valve, then through the control valve and to the sump.

When raising the hitch, fluid flows from the pump through the control valve to that rate-of-drop valve. But there is a check valve incorporated in the valve which lets the pressurized fluid bypass the valve and flow to the cylinder, raising the hitch quickly regardless of the setting of the valve. During the "lower it" operation, the fluid can't get through that check valve and has to go through the rate-of-drop valve, slowing its descent.

If your system is similar, and if that check valve were stuck open, the hitch would drop at full speed no matter what you did with the rate-of-drop valve.

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Does the engine sound like it's under a load when you try to raise the hitch? If not, maybe you have a linkage problem which is preventing the hitch from raising (or should I say rising?).

I don't know if this will help or not, but it might. The lever you use to raise the hitch does not directly operate the control valve. It works another lever (a pivot arm) which operates the control valve. The other end of that second lever is attached through some feedback linkage to the hitch itself.

When you raise your lever, you move one end of that pivot arm and cause the valve to open. But as the hitch raises to the right position, it moves the other end of the pivot arm and causes the valve to close again. In other words, there is feedback from the hitch to the valve causing the valve to close as the hitch reaches the desired position.

If something came loose in that linkage (e.g., the feed back linkage), then the valve might think the hitch is always in the right position and not move.

Good luck!