QuestionQUESTION: I have good pressure in c1 and c3,c2 is low 180 psi,high 180 psi, reverse is 80 psi, c4 has 50 psi for both reverse and inching pedal, lube test is 55 psi for low, intermediate, and high with reverse being 0 psi. All forward gears work as they should, but i have no reverse, after I purchased tractor reverse has worked sometimes and sometimes not worked. Any advise you could give me would be helpful.
ANSWER: All clutch pressures should be 195 to 210 psi. There should be pressure on C1 and C2 in first, C1 and C3 in second, and C2 and C3 in third. In reverse, only C4 with the pedal down, and C2 and C4 with the pedal up. C2 is modulated by the pedal. If C4 only has 50 psi, it's pretty obvious why it won't back up. There is a pressure leak either in the C4 clutch piston or the jumper tube. I'm sure the C4 clutch plates are worn out also. The tractor will have to be split and repairs made.
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QUESTION: Any chance it could be in the control valve assembly, and would it be wise to rebuild control valve before spliting tractor? Is that a high percentage that the c4 clutch is bad and no need to check control valve?
Answer If you want to check out the control valve, it's entirely up to you. It won't hurt anything. It will just take more time and who knows, you might find something else that needs attention. If the pilot spools stick, the clutches stay on when they aren't supposed to but it doesn't affect the pressure. A gasket can blow between the sections of the valve but it doesn't happen very often. With only 50 psi to C4 and it's been slipping for awhile, the clutch plates will be worn out and will need to be replaced even if you do find a problem in the valve. It's not as common for C4 to fail as it is for C1 or C2, but it does happen.
