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655813
Guest
Posting hyd info from recent fix. I am acft mechanic 34 yrs. recently my 1910 3 pt lift ceased to wk. I have a service manual and set out to fix it. 1st I tried the hyd press test as called out in the manual. The manual does not spell out the test very well but after all my work I got it figured out. you will never see press on the test gauge unless the spool screw on the diverter valve is turned counterclockwise to the aux position. even on a sys that is functioning normal. when the screw is turned counterclockwise you are shutting off oil flow to the rear of tractor. you can hear the press relief valve open returning oil to sump and get press reading if the pump is working. My symptoms were the lift arms lifted very slowly with no implement attached. with mower it would not lift it off the ground. Troubleshooting in the manual had several possible causes. I had press and heard the relief valve wking with diverter screw in aux. I put new seals on the lift piston and cleaned the saftey valve which is located in the flow control valve. Still had the same problem. I took the position control valve out which is inside the case in the wet oil cavity. The position control valve is what your hyd select levers are inputting to. I took the position control valve apart. My tractor is a draft with 2 levers so the valve has 3 segments. 1. main spool 2. lowering valve 3. ck valve. the main spool has a plunger inside it that when open diverts oil back to sump. when I took the main spool out I found the plunger jambed in the open position. would not slide back and forth was stuck. A little sliver of metal had broken off the end of the ck valve spring and wked its way into the plunger. I removed the metal and plunger bore and plunger were fine. reassembled and Eureka the hyd lift wks normal again. This was like finding a needle in a haystack. I hope this helps anyone wking on 1910 hyd systems.
