Combines hydraulics for header lift leaking down FAST

Remove header lift hose from valve. Then remove fitting that that hose hooked to. Under that fitting is a check valve. It is held in place by snap ring. Remove snap ring and then screw a 5_16NF bolt loosely into check valve. Now pull check valve. It won't come hard. Check for missing or badly damaged oring that seals OD of valve to housing. Also see that nothing is stuck under ball of check valve. Next I would remove plug that rate of lower screw screws into. There is a spring and poppet behind that plug. Be sure the spring has not broke and pieces locking the poppet open. You are thinking exactly right and problem has to be in lowering side of valve. Hope you find problem in first two areas. Might have to dig into pilot control under solinoid for sticking armature or problem with needle and or seat. If not that maybe an orfice. I'd have to dig out the ol book to get more accurate after you check the first two things. Good luck

Pulled the valve behind the outlet hose and the spring was broke. Pulled the lowering rate poppet and the spring was broke. All have been replaced now, header still leaks down but it tkes about 10-12 sec compared to the 4-5 sec before. Now have to chase down slower leak in valve.... Hmmmm

minniehill, As Dan mentioned,when you have the rate of lower poppet out you need to check the o-ring that is in valve that seals around poppet. This o-ring is now changed to a square o-ring for better sealing. I would assume that this o-ring is your problem. Hyper Harvest II

Did you replace oring around check valveIJ Did check valve ball or seat get marked up from broken springIJ Did poppet or poppet seat get damaged from broken springIJ Most poppet seats are removeable and are sealed up with oring. You might want to bend small hook into hard wire to see if poppet seat will come out. Next is that it isn't to hard to remove solinoid and pilot poppet. Pull pilot poppet seat to replace oring and examine pilot poppet needle to check for worn area on needle. It's got to be something still rather evident to leak down that bad. Good luck