NAA Hydraulic Check Valve Seat

[CAC63]

I read in the I&T manual for Hydraulic troubleshooting if the loaded lift slowly dropped a foot or so and stopped when the engine was shut off, then there was a leak associated with the control valve. If the lift continued to fall all the way down when the engine was shut off, then the leak was associated with the check valve. My lift falls all the way down in about 10-15 minutes under a heavy load. I replaced the steel ball and saw no improvement. Can anyone recommend how to recondition the seat or is this a waste of time?

Thank you to everyone for your wisdom. Because of you, I have a great operating and reliable tractor.
 

[Dean]

Probably a waste of time, but you may try seating the ball into the seat with a hammer and brass drift IF you are certain that you have replaced the old one with the correct sized ball. I always use a different ball to seat the seat than the one that I plan to install.

Are you CERTAIN that the lift piston is not leaking?

Dean
 

[CAC63]

I am certain the lift piston is not leaking. I replaced all the orings, gaskets, and follower pin last weekend. I took out all the plugs and sprayed all passages and small holes with brake cleaner. I made all adjustments according to the I&T manual. I even had a friend machine a Nuway tool gauge for setting the lift. All works great.
 

[JMOR]