Re: 318 Charge Check Valve?
Pek, The check valve need to do 2 things: NOT leak, and pop up when the engine/hydro runs. With seat pan removed, start tractor, warm for 2-5 minutes, and shut down. Move free wheeling lever to depress valves and then raise up to "storage" position. Start tractor and watch valves, they should pop up...no need to move hydro Frd/Rev lever.
Charge relief valve is actually for your hydraulic control levers for moving attachments. A pressure gauge can be installed in a front hydraulic outlet. Moving your lever should give a reading, ~around(??)~ 900 psi I believe. If you've got that, your fine.
After repairing/replacing site tube asm, drain oil, replace filter, and refill oil. I'd recommend JD Hy-Guard or Lo Vis, depending on temps where you live. You may find that your slowing down when hot went away!
One more! While your replacing fuel line components, pull hoses from fuel tank. You should have a filter or screen on the end of the tubes...clean or replace. Bob