Oil & Fuel B7001 Blowing oil from crankcase vent

[Garden State Mike]

Greetings- I am the owner of a B7001 Kubota tractor. I am not a mechanic but am trying to learn how to properly maintain this very handy machine.

Had recently developed a problem that I cannot properly diagnose. Shortly after the engine is running a stream of oil starts to blow out of the plastic hose connected to the valve cover vent. A mechanic where I work suggested it may be the ports that are cast into the engine may be clogged and not allowing the oil to drain down from the top of the engine.

Was wondering if anyone has any experience with this issue that can advise me before I start taking things apart.

Thank you.

 

[fj40dave]

I've been wrestling with a L295DT for a while....had the motor apart twice...and lot's of headaches along the way.....but, the orrig prob for me was the crankcase filling up with oil and coming out the dipstick hole under pressure.

Turned out to be a bad seal in the hydraulic pump shaft that was allowing 80w hyd oil to get into the crank case and overfill it.

As for the oil coming out the vent tube for the valve cover....sounds like you have a crank case pressurization problem.

Is the oil a constant flow or stream?
Is is just spitting out like it's under air pressure?
Is the crank case dip stick "pressurized" .... ie; when running, pull it, and does oil come flowing or blowing out?

I would think it very unlikely that the drains down through the head would be all plugged......there are several avenues for the oil to return to the pan.



Pull the valve cover & look...easy to do.
Try the oil dip stick check with it running.


Let us know!

 

[Garden State Mike]

Will check and reply by Thursday. Thank you.

 

[Garden State Mike]

Have checked the engine as you had suggested. After starting the engine, I pulled out the oil dip stick and oil was blowing out of the port that holds the dip stick. In addition, when the oil blows out of the valve cover vent it both streams out and blows under pressure. Did not remove the valve cover as I thought I would troubleshoot one item a time.

I am suspecting that oil under that much pressure is caused by hydraulic oil being pressured into the engine by the hydraulic pump which would indicate a bad oil seal where the hydraulic pump bolts onto the engine.

I have no experience with this issue but thought I might replace the seal to see if that will correct the problem. Do you agree?

I have an I&T shop manual and it shows exploded view diagrams of the hydraulic pump assemply but the drawing is not clear on which direction the oil seal should be inserted. Does it make a difference?

I have been trying to resolved this issue since last fall when the leak first started. Anticipating it being a hydraulic related issue I ordered replacement seals through an on-line parts supplier (Messick's). However, the seals they sent me were too large. Do the seals come in different sizes and is there a better way to order parts that will avoid time costly mistakes?

Sorry for asking so many questions. I took the next two weeks off from work to do the project that I bought the tractor in the first place. Looks like I will be spending that time repairing the tractor.

Appreciate your advice.

 

[ibnxe]

Your problem is not going to be the seal at the hydraulic pump, unless you are finding that the engine sump is constantly over full.
How long has it been since the last oil change? It is possible that you are having a simple blowby issue due to fuel contaminated oil. If it has been a while since last change, fresh oil and filter is in order. If the problem continues, have the engine checked for excessive blowby. Broken or worn rings will cause excess pressure in the crankcase.

 

[Garden State Mike]

I have drained and replaced both the oil and filter. The blow-by problem has corrected itself. Thank you very much for you appreciated advice. You have saved me a small pile of money and wasted time. :thumbsup: