JD 6300 SCV problem

[Anonymous-0]

I have a JD 6300 with about 4000 hrs. Tried to use one of the SCV"s the other day and the lever would not move forward. Traced cable back to rear of tractor and disconnected cable. Cable works fine. The cable hooks to a piston on the bottom of the valve that the cable pushes up or pulls down based on which way you push the lever. The piston will not pull down. I was able to get it to move a little but it is still pretty much stuck. It pushes up fine. BTW the other SCV is working fine. Any ideas on the problem and is this something I can fix or will I have to take it to the dealer.

 

[Tx Jim]

According to parts schematic the valve is a spool valve with a spring and poppet bolted on the end. Catalog lists 2 different tune up kits for each one.