JD 6430 Draft control over heats tractor

TheEquineFencer · Aug 12, 2013

A lady freind of mine is telling me her '08 JD 6430 will overheat if she engages the draft control and leaves it engaged. She found out the hydraulics for it is not supposed to run all the time after it was out of warranty. Any ideas? She's just stared engaging it when she really needs it for now. It's down right now because it appears the electric fuel pump is running backwards.

Edward. S · Aug 12, 2013

She may have dirty air filters, clogged up radiator.
What do you mean by draft control?
The 3 point hitch? what does she have on the back?
Is hers a premium or a standard 6430?
A Premium 6430 has closed center hydraulics that only run when needed. But a regular has a open center hydraulic pump that's running all the time.
Who installed the fuel pump backwards?

Tx Jim · Aug 13, 2013

Edward. S said:
A Premium 6430 has closed center hydraulics that only run when needed. But a regular has a open center hydraulic pump that's running all the time.

I checked JD parts and both the 6430 & 6430 premium use the same hyd pump. Can you please explain how one model can be open-center and the other closed-center utilizing the same hyd pump?Being a retired JD dealer service manager I'm knowledgeable on both types of systems on JD's older tractors but I can't understand how a pump could be open or closed. Thanks,Jim

TheEquineFencer · Aug 13, 2013

Air filters and radiators are clean. If you have to ask about draft control, you must not know this tractor. It's like my Ford, you can run the 3pt hitch with draft engaged or not. With it engaged, when it over loads, it'll pick up the 3pt hitch and not bog the tractor down. The Fuel pump was NOT installed wrong, the "guts" went bad and it started returning from the engine to the tank. I'm not up on the 6430, so I have no idea what a premium cab is. It has A/C and such enclosed. Hopefully she'll have the fuel system back right and get it back working. She sounded really down when I spoke with her yesterday afternoon. She lost a day of work and rain is moving in today.

Zebrafive · Aug 13, 2013

I think Edward S meant the 6430 Premium Series has a closed center PFC (pressure & flow compensated) hydraulic system. The Standard 6430 has closed center PC (pressure compensated) hydraulic system. Both systems use LS (load sensing). When no load, the PFC system lowers both pressure and flow until it (the pump) gets a LS signal. When no load, the PC system only lowers the pressure until it (the pump) gets a LS signal.

If you look on JDparts you should find the LS line from the valves to the pump.

Tx Jim · Aug 13, 2013

Zebrafive
After I left the JD dealership in '87 I haven't keep abreast of the later JD hyd systems. How does this PFC hyd system compare to Ford's CLLS hyd system?
Thanks,Jim

Edward. S · Aug 13, 2013

TheEquineFencer said:
Air filters and radiators are clean. If you have to ask about draft control, you must not know this tractor. It's like my Ford, you can run the 3pt hitch with draft engaged or not. With it engaged, when it over loads, it'll pick up the 3pt hitch and not bog the tractor down. The Fuel pump was NOT installed wrong, the "guts" went bad and it started returning from the engine to the tank. I'm not up on the 6430, so I have no idea what a premium cab is. It has A/C and such enclosed. Hopefully she'll have the fuel system back right and get it back working. She sounded really down when I spoke with her yesterday afternoon. She lost a day of work and rain is moving in today.

I have a 6430 Premium look at my picture on the left. . . . How do I not know it? I don't use draft control on it though and how would draft control over heat the tractor? Its not even giving it excessive load.

Zebrafive said:
I think Edward S meant the 6430 Premium Series has a closed center PFC (pressure & flow compensated) hydraulic system. The Standard 6430 has closed center PC (pressure compensated) hydraulic system. Both systems use LS (load sensing). When no load, the PFC system lowers both pressure and flow until it (the pump) gets a LS signal. When no load, the PC system only lowers the pressure until it (the pump) gets a LS signal.

If you look on JDparts you should find the LS line from the valves to the pump.

Yes that's what I meant sorry for confusion.

jd110 · Aug 13, 2013

TheEquineFencer said:
Air filters and radiators are clean. If you have to ask about draft control, you must not know this tractor. It's like my Ford, you can run the 3pt hitch with draft engaged or not. With it engaged, when it over loads, it'll pick up the 3pt hitch and not bog the tractor down. The Fuel pump was NOT installed wrong, the "guts" went bad and it started returning from the engine to the tank. I'm not up on the 6430, so I have no idea what a premium cab is. It has A/C and such enclosed. Hopefully she'll have the fuel system back right and get it back working. She sounded really down when I spoke with her yesterday afternoon. She lost a day of work and rain is moving in today.

I assumme you don't have a premium 6430. It would say premium on the hood. It is rare for a premium tractor's pfc hydraulic system to overheat. The "standard" 6430 PC sytem is more sensitive. The draft control being turned on should not overheat the hydraulics if everything else is in order. First, be sure the coolant level in the plastic tank is up to the "maximum" line. I have seen some overheat at minimum. The coolant gets an air bubble in the lines going back to the hydraulic cooler if it is too low. Second, make sure none of the coolantt lines going back to the cooler are pinched or kinked. The cooler is on the front of the transmission, just follow the lines to the engine - they go to the engine charge air cooler and engine oil cooler also. Another thing to look for is a pet peeve of mine on the non premium model. #1 scv has a constant-on detent that does not neutralize on it's own. Make sure that lever is not accidently left engaged and holding the system in High pressure "relief" it is not quite the same as a traditional open center system being held in relief, but it does create alot of extra heat and wear and tear on the pump.

jd110 · Aug 13, 2013

Tx Jim said:
I checked JD parts and both the 6430 & 6430 premium use the same hyd pump. Can you please explain how one model can be open-center and the other closed-center utilizing the same hyd pump?Being a retired JD dealer service manager I'm knowledgeable on both types of systems on JD's older tractors but I can't understand how a pump could be open or closed. Thanks,Jim

TxJim, The standard and premium do not use the same pump. unless it has the upgrade to PFC system. The standard PC system uses a gear pump where the PFC system uses an axial piston pump - very similar to the pump on a hydrostatic transmission.

oldnslo · Aug 13, 2013

Running hot would indicate that when in draft control it is dumping flow some where. Is it possible the draft linkage is not set properly allowing high pressure oil to be dumped to tank via a control orifice or relief valve.

Anyone have a detailed hydraulic schematic of the 3PH controls including the draft control portion.