John Deere Hydraulics

[rScotty]

What type of drive coupling or connection is between the front and rear pump. Just curious if that could have failed so the rear pump is not turning.

Exactly. What I would do next is simply remove the steering pump completely for further examination. Either the pump is completely toast or something's broken and the pump isn't even turning.

I agree with both of those ideas. Especially since you loosened the fitting on the steering pump ouput and got no flow out at all. Might as well hold off on the gauges until we find out if that steering pump is even turning.
From what we know now, it may not be.

If the coupling is, the pump is turning, and the rotors look OK, then does that put us back to the suction & manifold? Or is there some other thing we are overlooking?

Did you replace that molded rubber piece that sits above the pumps? The one with the dog-leg bend?

 

[Bdawg22]

Thanks for the ideas.
Yes I replaced the manifold that is F shaped on top of the pumps.

 

[rScotty]

Thanks for the ideas.
Yes I replaced the manifold that is F shaped on top of the pumps.

I see. It makes sense now. A peculiar way to make a manifold.......You would think an intake manifold would be bulletproof.

Anyway, it may be weird, but it worked once so can again. There should be a port to check the suction pressure at the intake and also prime the pump if necessary. Priming may be all it needs.

I see online that replacement 4310 pumps have a port on the front side not shown. Perhaps it can be primed through a similar port - or have you already tried that?

 

[Bdawg22]

I have not tried that. I will look into that before I take the pump apart

 

[Bdawg22]

Thanks. I am trying to remove the pump but don't seem to be able to figure out just how to do that. Do you know if there are any videos online that show the process?