My local John Deere dealer sells me parts, but is no help with trouble shooting. Long story short: It quit in the field. Pump locked up and broke shaft in trany. Replaced trans shaft and pump and rebuilt Hyd. pump. Cleaned hyd. system. The problem is that the front bucket and arms have no power. They will move, but do not have enough power to lift the front of the tractor off the ground. I have a gauge on the rear valve bank, witch shows the pressure of the bucket valve bank as well. The pressure will build to about 1100psi then falls to about 900psi. There are three valve banks witch run off the hyd pump: backhoe, extenda-boom, and front bucket. I have removed disassembled, inspected and cleaned all relief valves. At idle if you try to lift the front of the tractor with the front bucket I can hear and feel hammering in the valve bank. Any help would be greatly appreciated. Thanks, Dv8tion
I wanted to suggest a simple relief valve cleaning, but you already mentioned that. Does the replacement pump provide enough power for the backhoe? I am seeking clarification you have lots of pressure on the 'backhoe operations', but it is indeed only the front bucket and arms have no power. Does the "hammering" occur at any other ops - I am figuring it doesnt as that would be mentioned. * Just some questions directed at determining to make sure the only problem is the loader.
You should have a min of 2200 psi. something is still puggged. Also check the accmulator in the box under the left door next to the battries and make sure it isent plugged. Also check the preasure hoses from the pump to the valve bodies and make sure that pieces from the pump dident cut the hose on the inside and cause a flaper in the hose that will stop or slow the flow of hyd oil . I hope that helps.