Kubota hydraulic issues
- Thread starter Beaverplt
- Start date
- Views: 20325
kthompson
Elite Member
- Joined
- Sep 12, 2008
- Messages
- 3,509
- Location
- South Carolina
- Tractor
- Kubotas B2710, M6800, L6060 cab, Volvo EC excavator, 2 ZTRs and various implements.
No expert here but did this happen all at once? Was it working fine and you went to crank it up and this time it just did not work, or did it slowly get to this point over time?
Dave M7040
Elite Member
- Joined
- Dec 10, 2012
- Messages
- 2,757
- Location
- Williamstown Ontario Canada
- Tractor
- Kubota M7040 Nuffield 465
In looking at the free WSM available on line (and not too clear), there was a comment pertaining to your series of tractors and it has to do with bleeding out trapped air to get the pump to work.
I have attached the material from the WSM.
This is a first for me in terms of tractor hydraulic pump systems needing to be bled but perhaps it has to do with the L series.
I would start at the pump and loosen the smaller line which would be the high pressure line. Turn the tractor over but do not start it. Goal is to see if oil is being discharged.
If it is that is a good sign. Tighten the line and start the tractor.
Dave M7040
Attachments
I finally had an afternoon off to look at this issue. I loosened the high pressure line, cranked over the engine and got nothing out of the line. No air escaping. No oil spurting. Nothing. I'm guessing I've probably got a problem with the pump. I've looked for a rebuilding kit, but so far haven't seen one. If anyone else has, please let me know. Thanks
Dave M7040
Elite Member
- Joined
- Dec 10, 2012
- Messages
- 2,757
- Location
- Williamstown Ontario Canada
- Tractor
- Kubota M7040 Nuffield 465
Remove the discharge line completely and then pour some oil into the pump.
Crank the engine with the line off.
Goal is to see if there is any movement in the pump which would expel the oil you just dumped in.
Perhaps the pump's drive has failed..... i.e. new pump time.
If the oil you poured in is spit out then find a way to connect a supply of oil on the suction side of the pump.
An air leak on the suction side of the pump will stop any pumping but will not necessarily show as a leak....... deteriorated rubber hose.
See page from WSM stating pump is not re build-able.
Dave M7040
Crank the engine with the line off.
Goal is to see if there is any movement in the pump which would expel the oil you just dumped in.
Perhaps the pump's drive has failed..... i.e. new pump time.
If the oil you poured in is spit out then find a way to connect a supply of oil on the suction side of the pump.
An air leak on the suction side of the pump will stop any pumping but will not necessarily show as a leak....... deteriorated rubber hose.
See page from WSM stating pump is not re build-able.
Dave M7040
Attachments
rScotty
Super Member
- Joined
- Apr 21, 2001
- Messages
- 9,567
- Location
- Rural mountains - Colorado
- Tractor
- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
Before I pulled the pump off, I'd double check to see if the suction line is maybe not delivering any fluid to the pump. You could make up gallon jug of transmission fluid, hang it higher than the pump, and run a hose from the jug to the pump.It's suction, so the fitting doesn't matter so much as long as the hose to the jug is below the surface.
It should pull from the jug and shoot out the discharge, but before I believed that the pump just wasn't working I'd prime the suction line to get all the air out. Then if it still doesn't shoot oil out the discharge you know that the pump is not turning at all. Then it would be time to pull the pump and look at the pump drive shaft would be my thought.
On the other hand, it it did shoot oil out the pump discharge I'd celebrate and then go looking at the suction line on the tractor real carefully, because I'd figure that the suction line on the tractor either had an air bubble trapped in it or was plugged or was sucking air somehow.
It's odd for hydraulic pump on a tractor to just up and quit like that.
rScotty
It should pull from the jug and shoot out the discharge, but before I believed that the pump just wasn't working I'd prime the suction line to get all the air out. Then if it still doesn't shoot oil out the discharge you know that the pump is not turning at all. Then it would be time to pull the pump and look at the pump drive shaft would be my thought.
On the other hand, it it did shoot oil out the pump discharge I'd celebrate and then go looking at the suction line on the tractor real carefully, because I'd figure that the suction line on the tractor either had an air bubble trapped in it or was plugged or was sucking air somehow.
It's odd for hydraulic pump on a tractor to just up and quit like that.
rScotty
I would definitely remove the suction from the pump. You should be getting oil from the resistor at that point. If not you have found your issue.
Usually pumps dont go bad just from sitting. Another thing to check is the drive on the pump. If the pump isnt turning the pump wont pump. Not sure how that's done on this tractor.
Usually pumps dont go bad just from sitting. Another thing to check is the drive on the pump. If the pump isnt turning the pump wont pump. Not sure how that's done on this tractor.