SCV sticking

must8657 · Apr 27, 2011

I recently installed the 3rd SCV kit on my JD 4310. Some of you know that the tractor already has a 3 spool valve and the kit is basically just a handle and hoses.

After i first got the install complete, i could not move the 3rd SCV handle at all. I partially disassembled the SCV while it was still attached to the tractor. I was able to partially remove the spool for the 3rd SCV (couldn't get it out all the way due to obstructions). The spool did not show any signs of rust or gouges.

After spinning the spool a bunch of times and reassembling everything, i can now move the 3rd SCV with the handle. however, it isn't smooth at all and tends to stick (also doesn't seem to have full range of travel). i have to manually move it back to center and sometimes overshoot center because of it sticking. This isn't much of a problem when using it for the MMM, but i want to add a HTL and i can see this being a problem.

any ideas as to what is going on and can i fix it?

kennyd · Apr 27, 2011

Are you sure the linkage is not causing the problem? Is the spacer/bushing (#21) in place and lubricated?

beenthere · Apr 27, 2011

Sure sounds like the spool is binding up in valve. From what you describe, doesn't sound like the cable from the control lever to the valve is bent or binding.

If mine, I'd work it back and forth a lot of times in hopes that something will loosen up.

On the early 4300's, there was a screen in the system that would/could blow out and mess up some of the hydraulics, but believe that screen was replaced before the 4310's were built.

Last resort would be to remove the valve and see if you can find anything that needs a fix (or removing).

My 3rd SCV handle is a bit sticky, but I don't have any problem finding center when working the HTL.

must8657 · Apr 27, 2011

I am positive it isn't the linkage. i remove the linkage and it took a punch/hammer and some not so gentle persuasion to get the spool out.

I couldn't get the spool all the way out, but it was 3/4 of the way out and past all the grooves. I couldn't figure what would be binding. the spool didn't appear to be bent. Could the inside of the valve be rusted/pitted?

I have been working it back and forth. It is better, but not how it should be compared to the FEL operation.