Ford 8000 differential lock won't release.

[RCCB]

I have a 1972 Ford 8000 and it acts like the differential won't disengage. The tractor is very hard to steer and it I try to use the brakes to help steer, it kills the tractor. It was low on hyd fluid, but after I refilled it that did not solve the problem. The PTO and 3 pt both work. Any help is appreciated.

 

[rdbigfarmboy]

It runs on the low pressure pump same as pto clutch. Get the hydraulics hot and see what it does.

 

[RCCB]

I let it idle for 1.5 hours and it did not seem to help. Also, mowed for 4 hours with it and that did not help. I have noticed that the diff lock pedal will not stay up. I tried to hold it up with a block wood, but that has no effect. I disconnected the pedal and the rod that goes into the hyd pump just will drop as soon as you pull it up. Anybody have any ideas?