Kubota B26 blowing oil from vent

[woody]

On Saturday the 28th I loaded up the B26 and box blade to go straighten up a road that has not been touched in 20 plus years and just a little while into it I noticed oil blowing out the vent tube so I cut the tractor off and when I started again it didn't blow out for a while but eventually did several times I got the road done and went home.

I have tightened the suction line clamp at the pump replaced hydraulic filter thinking it was sucking air but when that didn't fix it I got to thinking maybe it's not air but pressure leaking by the relief valve and pressurizing the tank could this be happening or am I just grasping at straws?

I had this in another thread but thought it would get more attention here.

 

[wagne223]

The first 2 things that come to mind.....
1. Is the hydraulic fluid at the correct level? Not overfull.

2. Is the hydraulic oil cooler, clean? Free of dirt, grass and other debris.

 

[woody]

The first 2 things that come to mind.....
1. Is the hydraulic fluid at the correct level? Not overfull.

2. Is the hydraulic oil cooler, clean? Free of dirt, grass and other debris.

yes the fluid is at the correct level and the cooler is clean but the tractor does not have to run long enough to get hot. the oil level will rise to the fill plug and then go back down after I shut it off.

 

[100 td]

the oil level will rise to the fill plug and then go back down after I shut it off.

Generally, it's either sucking air and foaming up, or is full/contaminated with water and steaming/vaporizing up. Generally oil expansion won't increase the oil level much. If it is constantly relieving, why, check the 3pt is down and the selector valve is set correctly.
After sitting overnight, get a white or clear container and crack your rear axle drain plugs and let the oil drip into a container past the threads and see what comes out. Check the suction elbow on the pump for cracks/splits/leaks and clamp tightness.

 

[woody]

Thanks 100td, I don't think the tractor is running long enough to steam any water that might have gotten in it and I did drain oil from the drain plug after sitting overnight with no sign of water. I tightened the clamp on the elbow and tried to check it for cracks but I did not see any. I don't understand about the selector valve, check it how and where?

 

[wagne223]

yes the fluid is at the correct level and the cooler is clean but the tractor does not have to run long enough to get hot. the oil level will rise to the fill plug and then go back down after I shut it off.

Then I agree with 100d ......it has to be getting air into the suction side of the pump.

Even with the relief in full bypass, the fluid level in the tank should not change much.

Pressure is created by restricting flow. The bypass and fluid return lines are open unrestricted lines. Plus with a vented tank, it cannot build pressure. So I don't believe that is your issue.

 

[100 td]

I don't understand about the selector valve, check it how and where?

I don't know if the 26 has one or if the hoe is inline with the 3pt, the 21 has a 3pt or hoe select valve/lever. So yours may not have one, I'll have to check parts lists & manuals.(EDIT. Doesn't have a selector valve)
Also the oring on the suction line at the filter is a possibility. Make sure your 3pt is down.

 

[woody]

Thanks for the replies looks like it may be a few days before I can get back to it.

 

[sixdogs]

I have seen this on larger Kubotas and in both cases it was overfull oil. I would take the oil down some just to eliminate that possibility before other issues that are likely a lower probability. Always start with the easiest answer and work up from there. Next I would look for a plugged vent on the filler cap, assuming you have one. Just my free advice.

 

[woody]

I have seen this on larger Kubotas and in both cases it was overfull oil. I would take the oil down some just to eliminate that possibility before other issues that are likely a lower probability. Always start with the easiest answer and work up from there. Next I would look for a plugged vent on the filler cap, assuming you have one. Just my free advice.

Thanks, it is lowering it's on fluid plus I changed the suction filter and had to add oil back to it making sure I stayed just below the mark. The filler cap is not vented but the vent is right next to it and that is where the hydraulic oil is blowing out, now when I say blowing I mean pressure will continue to come out the vent tube after the oil stops.