Background if you haven't been following my situation. The auto header control with Dial-a-matic would only operate about 2 - 3 minutes from a cold start. After that it wouldn't lift the JD 220 platform, although the manual cab lever would easily raise the platform. Figured it must be a low pressure thing, but the auto header system could develop enough psi when the hydraulic oil was cold. As the oil warmed it got thinner and leaked past somewhere.
The main hydraulic valve under the steering column (manual header lift, reel lift/feeder house speed) feeds pressure to the secondary valve (swing auger, hydraulic cylinder speed) under the grain tank behind the cab. This secondary valve feeds the auto header control. What I found was a fitting that goes into the secondary valve that feeds the auto header control had an "0" ring that must have worn out. The "backer" was there in the inner groove, but no "O" ring with it. This fitting has an outer and inner "O" ring. When the inner "O" ring gets damaged it just dumps the pressurized oil into the return bore of the valve casting. At the main valve there is a similar double "O" ring situation. This one had NO "O" ring and NO "backer ring". When the oil was cold the clearance where the "O" rings were missing was narrow enough to build some pressure. When the oil would warm and thin the pressure would be to low to lift the header. Since the unload auger doesn't take that much to move especially when empty the lower pressures could still do it. Deere probably could have made the hydraulic system easier and more straight forward rather than connecting all of the components together in someway, but the way it is they can share relief valves. Anyway I think the problem is solved. The last phase if I have time is to convert my JD 220 platform with a toggle switch header control to a DAM header control. Works fine the way it is now with the JD adapter if time runs out. Thanks for every ones help.
The main hydraulic valve under the steering column (manual header lift, reel lift/feeder house speed) feeds pressure to the secondary valve (swing auger, hydraulic cylinder speed) under the grain tank behind the cab. This secondary valve feeds the auto header control. What I found was a fitting that goes into the secondary valve that feeds the auto header control had an "0" ring that must have worn out. The "backer" was there in the inner groove, but no "O" ring with it. This fitting has an outer and inner "O" ring. When the inner "O" ring gets damaged it just dumps the pressurized oil into the return bore of the valve casting. At the main valve there is a similar double "O" ring situation. This one had NO "O" ring and NO "backer ring". When the oil was cold the clearance where the "O" rings were missing was narrow enough to build some pressure. When the oil would warm and thin the pressure would be to low to lift the header. Since the unload auger doesn't take that much to move especially when empty the lower pressures could still do it. Deere probably could have made the hydraulic system easier and more straight forward rather than connecting all of the components together in someway, but the way it is they can share relief valves. Anyway I think the problem is solved. The last phase if I have time is to convert my JD 220 platform with a toggle switch header control to a DAM header control. Works fine the way it is now with the JD adapter if time runs out. Thanks for every ones help.
