John Deere Hydraulics

[Bdawg22]

I have a JD 4310 EHydro with steering, movement and PTO issues. I have replace the fluid and filter and cleaned the screen. Replaced the manifold on the pump. Lifts work but the three things operated by pump LVA11451 are not working. Is there any way to check to see if the pump is working or should it just be replaced. I do not have any gauges to check pressure.

 

[rScotty]

Often when nothing works it is because the pump is not getting pure fluid. It has to suck the fluid from the sump, and if there is the slightest air leak in the hose from sump to filter to pump then the fluid gets frothy and nothing works right..
You might want to renew all those suction hose connections between sump and pump..

It is very rare for a pump not to work, but running a pump with air mixed in with the hydraulc fluid will eventually do it.

I'm curious why replace the manifold on the pump? Did it accomplish anything?

Amazon sells pressure testing kits with gauges.

 

[Bdawg22]

I replaced the manifold because that is where I was told most leaks occur. This is the F manifold that connects to both pumps.
I loosened the connections on the bottom of the pump but it did not leak fluid when I started the tractor I loosened the connection on top where the manifold connects and fluid does come out of the manifold. Still not sure it is getting into the pump though.

 

[rScotty]

I replaced the manifold because that is where I was told most leaks occur. This is the F manifold that connects to both pumps.
I loosened the connections on the bottom of the pump but it did not leak fluid when I started the tractor I loosened the connection on top where the manifold connects and fluid does come out of the manifold. Still not sure it is getting into the pump though. View attachment 3201138

The common manifold problem is probably an air leak. Without gauges to test the output of the pump, we can only work on the suction to the pump.... and without gauges we don't know if we are getting anywhere. About all we can do is loosen a fitting and see if oil comes out.
It will be slow picking at it without a pressure gauge. The pressure gauge kits have the adapters in the kit so all you have to do is taie a fittng off insert the adapter and plug in the gauge. Prices on the kits run 50 to 200 bucks. Less than a mechanic charges.

But we can try to guess. Which lift is working? What 3 things are not? What is the history - how did this all start? Is the HST working?

Do you have a shop manual with a hydraulic flow schematics.
BTW, most hydraulic problems are easy to fix once you find them. I wouldn't start throwing parts at it.
rScotty

 

[Bdawg22]

I will see what I can find as far as gauges are concerned.
The front lift and the back lift be both work. The power steering, PTO and the ehydro pedals won’t move forward or reverse. The only code I get is a long, short, short, long

 

[Harry in Ky]

I'm no authority on that tractor but what you described says only one of the two pumps is working. The lift and hydraulics will be one pump. The other pump will supply steering, transmission (charge) and PTO clutch operating pressure. You need to look and see which pump is which, and determine if the steering pump is working at all. You don't need gauges just figure out that a pump isn't moving any oil. Loosen the line nut on the steering pump, start the tractor, and see if any oil is spilling out of the loose fitting. Simple starting point.

 

[Bdawg22]

Based on the picture in an earlier post the front pump (left end) is the one in question. I loosened the nut on the bottom side still did not get oil coming out. I may try that again just to be sure.

 

[kennyd]

We sell gauges that are built and ready to use.

What did the old oil look like when you removed it?

 

[oldnslo]

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.

 

[Harry in Ky]

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.

 

[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?