Deere 6400 Lost all Hydraulics Except PTO

[J_J]

I am not understanding you at all. Every hydraulic pump has a suction tube in the sump or reservoir. If he does not have pressure at the priority valve, then the pump feeding that circuit is not working, whether it is the hydrostatic pump, or a separate gear pump

 

[kenstrac]

He says he has fluid shooting out so the pump is working it is being diverted to sump instead of the PS 3PT brakes and front pump.If he starves the variable displacement pump on the front it will cook.

 

[russhog]

I have a syncro transmission on the 6400. I don't have a test port on the filter. I checked the pressure at the main pump in the rear and didn't have any pressure. There is a charge pump under the tractor but i don't know if there is a way to check it with a test fitting. If i understand it correctly, the fluid goes from the sump to the charge pump, to the filter and then to the main pump. From the main pump to the priority valve. I had no pressure at the priority valve either. Any ideas?