JD 4300 stops moving in forward and reverse after a few minutes - engine still runs

[Zebrafive]

What pressures does the TM (Tech Manual) for the forward/reverse ports show if OK?
I am guessing 10,000psi covers a lot of different JD equipment. It seems way too high to get accurate low pressure readings.

I am assuming you have the TM

 

[GreenRust]

What pressures does the TM (Tech Manual) for the forward/reverse ports show if OK?
I am guessing 10,000psi covers a lot of different JD equipment. It seems way too high to get accurate low pressure readings.

I am assuming you have the TM

6000 psi +/- 200 for the pump pressure and 100-150 psi for charge pump pressure. I was looking at a test set like this Hydraulic Pressure Test Coupling Kit it looks like imported junk but I can't see using it more than a few times. If the pump or valves are bad it requires splitting the tractor which would require stands and other tools I don't have. I think I could actually do it but considering expense and time I would take it to a real mechanic at that point.

 

[jthibodeau89]

The coil is the cruise control. An electromagnet holds the forward pedal position when engaged.

In my opinion, if it were a linkage issue, it would not come back when cool. I broke my forward linkage bar, and the pedal went to the floor. Reverse worked fine, but no forward. Had to split the tractord to replace the link bar that broke.

I assume that you changed the hydrostat filter up in the tunnel, correct.

 

[jthibodeau89]

My local JD shop would not quote a time estimate to split my tractor. Only $145/hr.

I built the stands in a couple afternoons. Where are you located?

 

[GreenRust]

I assume that you changed the hydrostat filter up in the tunnel, correct.

I did change the transmission fluid filter and the suction screen, is there something else I should have changed too?

 

[jthibodeau89]

No, just the big filter on the front of the trans. Did you confirm the rubber inlet on the pump? Time to check pressures at trans.

 

[Zebrafive]

6000 psi +/- 200 for the pump pressure and 100-150 psi for charge pump pressure. I was looking at a test set like this Hydraulic Pressure Test Coupling Kit it looks like imported junk but I can't see using it more than a few times. If the pump or valves are bad it requires splitting the tractor which would require stands and other tools I don't have. I think I could actually do it but considering expense and time I would take it to a real mechanic at that point.

Ok, for 6000psi, a 10,000psi gauge would be right.

 

[Zebrafive]

The coil is the cruise control. An electromagnet holds the forward pedal position when engaged.

In my opinion, if it were a linkage issue, it would not come back when cool. I broke my forward linkage bar, and the pedal went to the floor. Reverse worked fine, but no forward. Had to split the tractord to replace the link bar that broke.

I assume that you changed the hydrostat filter up in the tunnel, correct.

Thanks for ID of coil.
You're probably right, if shutdown/cooling, it runs a few more feet, linkages would not fix themselves.

 

[GreenRust]

Did you confirm the rubber inlet on the pump?

It just dawned on me that I should double check that. Rubber hose with clamps seems like a weak point.

Your home made stands look great. If I was anywhere near you I'd be making you an offer to try to rent them or might try to weld something up myself. But, to be completely honest, I can't see trying to split the tractor myself. I'm still learning all of this as I go and I don't want to spend the rest of my life hearing I told you so if I didn't fix or made it worse from my otherwise very supportive wife!

 

[Zebrafive]

6000 psi +/- 200 for the pump pressure and 100-150 psi for charge pump pressure. I was looking at a test set like this Hydraulic Pressure Test Coupling Kit it looks like imported junk but I can't see using it more than a few times. If the pump or valves are bad it requires splitting the tractor which would require stands and other tools I don't have. I think I could actually do it but considering expense and time I would take it to a real mechanic at that point.

I would make SURE the kit has the correct adapters. It has 6.