426 cat backhoe

[Johndeere9610]

I have a 426 backhoe that will not move it act likes the pump it in just isnt building pressure?

Any Ideas

 

[cummins_255]

have you hooked a pressure gauge to see what the line pressure is?

 

[Johndeere9610]

No. But I can tell you that there is no pressure on the back pressure port.

 

[4x4dually]

Not knowing much about your particular setup, I'm assuming that it uses a positive displacement pump. If that is the case, could the relief valve be stuck open or damaged relieving all the pressure back to the tank?