3020 only steering and brakes

[rblinhart]

I have a 3020 that I replaced the main hydraulic pump in. Rebuilt pump worked for 2 weeks and now I only have steering and brakes. No rockshaft or scv operation at all. I only replaced the pump because it was noisy when hot. The tractor has new filter and clean oil in it, and I have disassembled the priority valve and don't see anything wrong with it. The tractor is a diesel and syncro range transmission. Before I rip the pump back out thought I would see what information was out there. Figuring something has stuck in the pump but any info you would have will be greatly appreciated! Thanks Rob

 

[Tx Jim]

Did you change hyd filter & check/clean hyd oil suction screen? You need to check hyd stand-by pressure to be sure it's 2250-2350 psi. You will need to check hyd pressure on RH side of hyd pump. One possibility is pressure control(priority) valve is blocking flow.

 

[rabrac]

De-stroke the main pump and then try it again. The priority valve could be causing the problem and yes you should have steering & brakes that is the safety feature of the priority valve. Make sure the transmission pump is supplying good flow of oil to the front main pump.

 

[Tx Jim]

Hyd pressure needs to be above 1700 psi in order to open pressure control valve so 3pt & scv's can have pressure

 

[JIM MN]

Your priority valve is working. You need more main hydraulic pump pressure? Put a gauge in the rear remote cylinder outlets, see what your pressure is? You need 2100-2200 psi +-.