Both my hydraulic control valves (for the remotes) were leaking. Took 'em off and apart,carefully,replaced all the o-rings. One stopped leaking and the other didn't. I've had it apart three more times over the past two years and it still leaks from the cap plug (where you make the unlatching adjustment). I have replaced the unlatching piston two times as well as all the other o-rings both times. I have looked for any obvious wear or damage to hard parts but my untrained eye can't see anything out of the ordinary. I've looked carefully at the replaced o-rings and have not nicked or cut them. I'm lost. Anyone have any tips or help? I'd like not to have to buy a complete valve ($$$) but figure to give it one more try before giving up and lightening my already featherweight wallet. I hope some of you (Tractor Vet??) will have some useful advice for my "fifth try is a charm" attempt.