Old Tractor Hydraulics

[WNYBill]

My old Kubota 7030 remote hydraulics quit working after a couple of hours and it gets warm/hot. I am sure the pump is tired, but I priced them and looked at replacing. I guess not, almost looks like I may have to remove part of the FEL frame. So, we only use this tractor in the summer. Isn't hyd oil #10 weight? Could I improve things if I used 30 weight? Or is there something else I could do?

 

[Jim.ME]

My old Kubota 7030 aux. hydraulics quit working after a couple of hours and it gets warm/hot. I am sure the pump is tired, but I priced them and looked at replacing. I guess not, almost looks like I may have to remove part of the FEL frame. So, we only use this tractor in the summer. Isn't hyd oil #10 weight? Could I improve things if I used 30 weight? Or is there something else I could do?

Hydraulic oil can be different viscosities, not just 10wt. Many tractors of this vintage use a UTHF, not straight hydraulic oil. What does your Operator's manual call for?

 

[WNYBill]

Tractor Supply Hyd oil meet the spec and that is what I use. But after warming up, I lose pressure, and I am trying to correct that problem. Never saw a viscosity on pail, but it is thin.

 

[MJMJ]

You're not going to correct that with different fluid.

 

[Jim.ME]

Tractor Supply Hyd oil meet the spec and that is what I use. But after warming up, I lose pressure, and I am trying to correct that problem. Never saw a viscosity on pail, but it is thin.

Someone might be able to tell you the viscosity, if you tell which TSC hydraulic oil you are using (full name, part number, sku number etc.).

As MJMJ said thicker oil won't correct the problem. Thicker oil may just give you a few more minutes before it is warm enough to act the same way.

 

[WNYBill]

You're not going to correct that with different fluid.

So my loss of hyd pressure is due to the pump leaking? The only fix is a new pump? Can they be rebuilt?

 

[buickanddeere]

Is there an oil cooler ? Is the supply to the pump restricted ? Is a thermal relief valve opening ? Are you going to just guess and throw $$$ parts at it and hope to luck out ?

 

[WNYBill]

That is exactly what I am trying to avoid by asking questions. The FEL works off one rear remote and I have a heavy offset disk on the other. The 3 point always works. When the tractor is cold everything works. Never worked the FEL or the 3 point hard enough to get the oil hot. Can't lift the disk after running for several hours and the oil gets hot, tractor does not overheat. No cooler and no apparent damage to oil lines. Don't know if it has a thermal relief valve.

 

[Jim.ME]

That is exactly what I am trying to avoid by asking questions. The FEL works off one rear remote and I have a heavy offset disk on the other. The 3 point always works. When the tractor is cold everything works. Never worked the FEL or the 3 point hard enough to get the oil hot. Can't lift the disk after running for several hours and the oil gets hot, tractor does not overheat. No cooler and no apparent damage to oil lines. Don't know if it has a thermal relief valve.

A service manual should have some info and may have troubleshooting info to help pinpoint a problem. Do you have a service manual for it so you can at least check pressures when cold and hot?

Is this a new or old problem?

Is it a single acting cylinder loader or how is it plumbed if one remote is running double acting cylinders

 

[MJMJ]

So my loss of hyd pressure is due to the pump leaking? The only fix is a new pump? Can they be rebuilt?

Not necessarily. Could be several things. You'll probably have to go through the manual troubleshooting guide to pinpoint the issue.

 

[DRussell]

My old Kubota 7030 remote hydraulics quit working after a couple of hours and it gets warm/hot. I am sure the pump is tired, but I priced them and looked at replacing. I guess not, almost looks like I may have to remove part of the FEL frame. So, we only use this tractor in the summer. Isn't hyd oil #10 weight? Could I improve things if I used 30 weight? Or is there something else I could do?

Personally, i doubt the problem is the hydraulic pump. Do you have a service manual for it? Get an oil filled 5000 psi gage and plumb it to fit one remote on the tractor. That will tell you the pressure on the system when you operate that remote.

Does the 3 point hitch work when it gets hot? With a load on it?

Does the loader work when it gets hot? Your problem might be as simple as the cylinder on the disk.

 

[rick n ohio]

My old Kubota 7030 remote hydraulics quit working after a couple of hours and it gets warm/hot. I am sure the pump is tired, but I priced them and looked at replacing. I guess not, almost looks like I may have to remove part of the FEL frame. So, we only use this tractor in the summer. Isn't hyd oil #10 weight? Could I improve things if I used 30 weight? Or is there something else I could do?

I would start with new hydraulic filter.

 

[WNYBill]

DRussell, pm sent Thank all you guys, working with junk is fun!

 

[DRussell]

DRussell, pm sent Thank all you guys, working with junk is fun!

Replied to your PM. Let us know how it works out for you.

 

[bc]

I don't think it is a pump problem. Pumps are just some spinning metal parts. They don't work great for a couple hours then slow down when hot and then work great again when cold. It has to be something in the filters or the valves somewhere such as sticking or plugging that makes the fluid get hot.

 

[WNYBill]

I am researching the relief valve. And really have no idea what I am looking at or for. If the detent on the remote wasn't working correctly, could that cause this problem? I do remember after changing the filter last year it acted like the pump had lost its prime, let it run for 5 minutes and it started working.

 

[DRussell]

https://shop.kubotausa.com/oemparts...14f81bfb6a/m7030dt-n-b-hydraulic-system-parts

Here is a link to the online diagrams of the Kubota M7030 hydraulic systems. Your best option is to obtain the service manual and/or contact your closest dealer.

 

[BarnyardEngineering]

I don't think it is a pump problem. Pumps are just some spinning metal parts. They don't work great for a couple hours then slow down when hot and then work great again when cold. It has to be something in the filters or the valves somewhere such as sticking or plugging that makes the fluid get hot.

Spinning metal parts wear, and pumps do exactly that... They lose pressure as the hydraulic oil thins out when clearances get excessive. In this instance "great" is just "barely adequate" because it doesn't take anywhere near full capacity of the pump to make the loader go up and down or the disc to go up and down. The empty 3pt takes almost no pressure whatsoever to go up and down so that really doesn't tell us anything.

I'm not saying that it necessarily is the pump, just that it could be the pump.

 

[BarnyardEngineering]

I am researching the relief valve. And really have no idea what I am looking at or for. If the detent on the remote wasn't working correctly, could that cause this problem? I do remember after changing the filter last year it acted like the pump had lost its prime, let it run for 5 minutes and it started working.

The relief valve only comes into play when the system is "dead-headed" meaning the loader is all the way up and you keep pulling the lever, or if you try to lift something that's too heavy for the loader. Generally speaking when the hydraulic system is "on demand" and there is nowhere for the oil to flow.

You can generally detect when the relief valve is operating by a hiss or screech coming from the tractor.

 

[showcrop]

What DRussel posted about checking pressure with gauge. quick and easy.