Rear hydraulics on a M reg 7745

[dalvey]

After taking off a rear digger we found that the tractor arms would no longer lift. It appeared that there was plenty of oil pressure as you could hear it pumping in the external circuit when the leavers where operated.

At this point we removed the top cover thinking that a leaver had become disconnected but this was not the case. Next we re-sealed the black box and rebuilt the tractor.

On startup the arms came straight to the top without moving the leavers. The arms will now not go down. There also does not sound as much pressure on the external circuit.

I hope someone has some ideas as it has been several weeks since this happened and the engineers show no sign of arriving to repair it.

 

[treaney]

Could be an airlock. Loosen a banjo bolt on a hydraulic supply feed pipe.

 

[Renze]

On the 5245 we once bent the half moon shaped thingies, on which the feeler rollers roll. Get what i mean ???

Anyways, it was a bent lever on the inside, it was hardly visible but the dealer found out when testing it while the lift cover was on the workbench, and we tested it with air pressure. Just cover your air blasting gun with a rag to seal it a bit and apply pressure to the P port: Then move the lever and check whats happening.

The lever got stuck because it was bent: the bend was probably caused from working with the 3pt hitch scoop, when pushing it back over, it pulls the pushrod out of the piston: when you drive forward and the scoop rolls over its top dead point, it comes down with a smack, which can bend your lift levers because the lift drops down without friction, causing the levers to overspeed: when the roller busts into the cam again at full drop speed, it bends a lever.