NDDan
Guest
I imagine you are talking ground speed varible. If you have a '79 or prior you need to replace needle and seat kit (poppet kit) for ground speed. Also them prior machines have a brass check valve with rubber seal on it next to solinoid for varible. That check valve would normally cause varible to speed up but I believe it could cause it to slow down if you have not used function that raise system pressure for extended periods of time. Providing there is no external leak the problem has to be in valve. Be sure anti-magnetic washer is in place next to armature also. If you don't find problem hear you must have pin hole within valve casting leaking off the oil. This beings the case you need to visit salvage yard for valve. I have not found this a problem at all and replacing worn poppet kit will fix 99% of the time. If you have a '80 or newer you need to replace both the poppet kits. They have two kits. One used for ground speed increase and one for decrease. Most common would be kit for the decrease side. If you should be talking header varible the apropriate poppet kits are at fault unless you have external leak or pin hole in valve casting. Good luck