M7030dt hydraulics not working

[ranger danger]

I have an opportunity to buy a 4x4 M7030 for a real good price. The tractor has no hydraulics installed on the front and the rear 3 point hydraulics are not working. Otherwise, the tractor runs and drives great!! The current owner has replaced the hydraulic pump 2 times with known good ones and both times the pump went out almost immediately. He purchased the tractor with this problem so, we have no idea of the history of the issue. According to a local tractor mechanic, if there is a problem somewhere else in the system that will not allow the pressure to circulate, it will cause the pump to burn out almost immediately. What could be causing this problem other than a bad pump?

 

[100 td]

A dead headed pump, someone may have removed a loader or similar and capped/plugged the lines, and dead headed the pump. There may be a valve which needs turning to remedy this, or a plate required or loop of hose.

 

[ranger danger]

A dead headed pump, someone may have removed a loader or similar and capped/plugged the lines, and dead headed the pump. There may be a valve which needs turning to remedy this, or a plate required or loop of hose.

I do know it never had a loader on it. Please excuse my ignorance. What, where and how much is a "dead head pump"? Thanks

 

[100 td]

Blocking of the pump flow without a relief valve in circuit, the pressure will build up until something bursts or breaks.

 

[ranger danger]

The factory loader for this tractor has its own pump that is chain driven off the front of the engine. I did a little reading about "dead head" Its a condition where a valve to accommodate flow is closed and causes overheating in the pump to catastrophic failure. Correct?

 

[100 td]

Go here and put you model in and look for valves in the hydraulic circuit.
https://apps.kubotausa.com/illustrated-parts/
Take some picture of the pipes leaving your pump and follow the lines. Post them up and folks here will be able to see if something is aghast. Are there any hoses or remote valves on the tractor, take pics as well.

 

[ranger danger]

Go here and put you model in and look for valves in the hydraulic circuit.
https://apps.kubotausa.com/illustrated-parts/
Take some picture of the pipes leaving your pump and follow the lines. Post them up and folks here will be able to see if something is aghast. Are there any hoses or remote valves on the tractor, take pics as well.

Thanks, Ill have to go out to the farm later and look.

 

[100 td]

The pump is a postitive displacement pump, when it spins, the oil has to go somewhere, it usually goes through the pipes and valves uninhibited back to tank. When a valve is selected, the oil flow is directed to whatever is hooked up, when the implement (cylinder say) comes to the end of the stroke, the pressure relief valve opens and allows flow back to tank. For some reason your pressure relief is not working, or not in circuit, and your flow has nowhere to go. Taking pictures of all lines and valves may allow someone here to pick up something unusual. Your problem could be in an internal valve though.

 

[North Idaho Wolfman]

That model has 4 different variations of the hydraulic pumps, valves, and lines.
And no not all models used a drive pump off the front of the crank for the loader power, some used the main system for supply.

It also might not have normal relief valve, it might have an unloader valve, which works differently than a normal relief valve, there are also different unloader valves possible between the variations, and yes diffent relief valve options and locations.

Get the serial # off the tractor, and take pictures of the pump and lines, as they are different between the different model variations.