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

[beenthere]

GreenRust
Thanks, I will check mine. 22 years and as far as I know, still good. But need to check it out to confirm that.

 

[jthibodeau89]

Frothing oil would cause what you described. Hopefully there isn't any damage to the hydrostatic pump and motor. I would not run it again until the inlet is repaired.

 

[TractorGuy]

I'm wondering where the suction screen got off to? You don't reckon it was ingested into the system do you?

 

[Zebrafive]

The (fabric covered) fuel lines on our 6200 looked like WW II surplus and all started leaking in a short time. Just makes me wonder what gives with such a corporate leader/giant.

Same for my JD 6415, fuel lines started leaking at the clamps. I was able to cut 1" off the hose and reconnect the lines, but that was a short term fix. I replaced all the lines with Gates barricade hose.

 

[texasranger556]

There is a poppet valve that controls the charge pressure for the transmission. On my 4400 it was not seating and causing cavitation, could feel the hydro pedal chattering especially at low RPM but would still drive at high RPM. It is located on the transmission near the cartridge filter, just an allen head bolt, spring, and the valve seat.

Mine somehow got wedged sideways, just had to remove and reinstall. Been fine for about 100 hours since.

 

[GreenRust]

I'm wondering where the suction screen got off to? You don't reckon it was ingested into the system do you?

It is a mystery. I don't think it would drive at all if the screen blew out and got gobbled up by the works.

There is a poppet valve that controls the charge pressure for the transmission. On my 4400 it was not seating and causing cavitation, could feel the hydro pedal chattering especially at low RPM but would still drive at high RPM. It is located on the transmission near the cartridge filter, just an allen head bolt, spring, and the valve seat.

Mine somehow got wedged sideways, just had to remove and reinstall. Been fine for about 100 hours since.

Interesting, I do not have any chatter or change in behavior with changes in RPM but I am going to check that.

 

[GreenRust]

I changed out the rubber suction manifold and completed the hydraulic system bleed procedure. Absolutely no difference. I still have the same exact issue. I really think I'm at the point where I have to throw in the shop towel and get a pro working on it. I hate giving up but I can't keep throwing parts and time and this when I clearly do not have a path to victory here. I know the next logical step is to check the pump pressures but I probably won't to that. Here's why, I still do not have test gauges. So let's say I spend more money and buy them. There are really only two outcomes. One, the pressure tests pass and I'm in the same spot with no ideas left on what to fix and have to take the tractor in or two, the pressure tests fail and as I do not have the tools or time to split the tractor I still need to take it in. Two options with the same outcome. My gut tells me that since it drives just fine for a few minutes then quits (engine is still strong) that I am missing something really dumb to someone that actually knows what they're doing. I appreciate the time everyone has taken trying to help, I just don't think there is anything else I can do on my own.

 

[rekees4300]

I just don't think there is anything else I can do on my own.

Yes, often a telephone is the best "tool" to use.

 

[pmsmechanic]

It sounds like something is warming up and expanding and causing the pump to loose prime..... Thinking as I'm typing.... the hydrostatic pump is inside the transmission. It has nothing to do with the external pumps on the side of the engine. Normally there is also a charge pump inside the transmission housing that keeps the hydrostatic pump charged with oil.

Also are the hydrostatic controls mechanical or are they electric over hydraulic like on my 4410? If so it could be something electrical.

 

[GreenRust]

It sounds like something is warming up and expanding and causing the pump to loose prime..... Thinking as I'm typing.... the hydrostatic pump is inside the transmission. It has nothing to do with the external pumps on the side of the engine. Normally there is also a charge pump inside the transmission housing that keeps the hydrostatic pump charged with oil.

Also are the hydrostatic controls mechanical or are they electric over hydraulic like on my 4410? If so it could be something electrical.

The 4300 does have a charge pump too, both are inside. To the best of my limited knowledge the controls are all mechanical.