Egon
Epic Contributor
Change the fluids and filters; then asses the situation.
Kubota b7200 Black hydraulic fluid/ bubbling out of dipstick
- Thread starter Beastman14
- Start date
- Views: 14148
Jim Nelson
Platinum Member
I used to have a B7200 HST that I bought worn out and it started dumping trans./hyd. oil into the engine so I pulled the pump and changed the seal. This didn't help so I ended up changing the whole pump which did solve the problem. I've seen a couple of other threads in the past where this happened but it was always a HST rather than gear tractor so it's quite possible that it's a different system.I hope you get it figured out and get it fixed reasonably easy.
OP
Beastman14
New member
Hello all. Thanks for the replies. First things first I am fairly mechanical but very unfamiliar with these little Kubota s.
So I changed all fluids in machine and this is what I have found..... Hydraulic fluid was way over filled due to a cracked boot on shifter allowing tons of water in. So I changed fluid and things look better and at correct level and trans fluid is no longer overflowing out of the dipstick. I also cleaned the filter screen.
Now....The tractor loader is still very slow and has very little lifting power (same as before changing fluid and cleaning filter). The hydraulic oil also is full of bubbles and is foaming a lot. I know this could be a suction leak, but due to lack of loader strength I am thinking I have a bad pump. 3pt hitch seems to be working but spongy so I know there is air in the system. Could a bad pump be pulling air in and resulting in weak hydraulics? What else should I do to further diagnose?
So I changed all fluids in machine and this is what I have found..... Hydraulic fluid was way over filled due to a cracked boot on shifter allowing tons of water in. So I changed fluid and things look better and at correct level and trans fluid is no longer overflowing out of the dipstick. I also cleaned the filter screen.
Now....The tractor loader is still very slow and has very little lifting power (same as before changing fluid and cleaning filter). The hydraulic oil also is full of bubbles and is foaming a lot. I know this could be a suction leak, but due to lack of loader strength I am thinking I have a bad pump. 3pt hitch seems to be working but spongy so I know there is air in the system. Could a bad pump be pulling air in and resulting in weak hydraulics? What else should I do to further diagnose?
OP
Beastman14
New member
Oh and the 3 pt hitch also seems to be working and strong as it lifts my 3pt hitch snowblower up no problem but is spongy when arms are up so I know there is air in the system.
Dave M7040
Elite Member
- Joined
- Dec 10, 2012
- Messages
- 2,757
- Location
- Williamstown Ontario Canada
- Tractor
- Kubota M7040 Nuffield 465
I am suspecting something is wrongly connected in the loader hoses and valve. Double check this.
To verify the pump condition, a pressure gauge for about $30 from any hydraulic shop will provide a lot of info.
If you have a quick coupler anywhere disconnect it and connect the gauge. Run at full rpm and then send pressure to gauge for a second or two and read the pressure.
Dave
pmsmechanic
Elite Member
- Joined
- Dec 6, 2013
- Messages
- 4,224
- Location
- Southern Alberta, Canada
- Tractor
- 4410 and F-935 John Deere, MF 245
Dave is the op going to get a accurate pressure reading if the pump is sucking air?
rScotty
Super Member
- Joined
- Apr 21, 2001
- Messages
- 9,575
- Location
- Rural mountains - Colorado
- Tractor
- Kubota M59, JD530, JD310SG. Restoring Yanmar YM165D
Not Dave, but the answer is yes. Pressure is pressure whether it is air or water or a mixture of both. Hydraulic fluid with air in it can still do a respectable amount of work. But since air is compressible where fluid is not, the bubbles in the oil will act like tiny springs and make whatever the hydraulic cylinder is doing feel "spongy" instead of solid.
rScotty
LouNY
Super Star Member
- Joined
- Jul 4, 2015
- Messages
- 12,380
- Location
- Greenwich, NY
- Tractor
- Branson 8050, IH 574, Oliver 1550 Diesel Utility (traded in on Branson) NH 8160. Kioti CK2620SECH
If someone is going to the trouble of connecting a gauge to the quick connect go a bit further add a needle valve and a return line so you can check pressure at flow.
If your tractor is rated for 2500# at 10 gpm, with a half wore out pump you can still achieve pressure with low or no flow, pressure is only half the solution.
Back to the original post if your fluid is getting highly aerated there is a problem;
could be the type of fluid, low fluid, to high a fill, a suction leak leading to the pump.
If it is an engine mounted pump there are several places it could have a suction leak, the filter, the filter mount, the line leaving the filter, the line attachment to the pump or even the line its self.
If your tractor is rated for 2500# at 10 gpm, with a half wore out pump you can still achieve pressure with low or no flow, pressure is only half the solution.
Back to the original post if your fluid is getting highly aerated there is a problem;
could be the type of fluid, low fluid, to high a fill, a suction leak leading to the pump.
If it is an engine mounted pump there are several places it could have a suction leak, the filter, the filter mount, the line leaving the filter, the line attachment to the pump or even the line its self.
Dave M7040
Elite Member
- Joined
- Dec 10, 2012
- Messages
- 2,757
- Location
- Williamstown Ontario Canada
- Tractor
- Kubota M7040 Nuffield 465
Since the owner reports that the 3 pt lifts a heavy implement without a problem I am inclined to think the "sucking air" scenario is wrong.
the 3 pt hitch also seems to be working and strong as it lifts my 3pt hitch snowblower up no problem
How many times have we had new forum members post about erratic FEL and swear nothing was changed and then, with submitted photos, it becomes clear that a hose is in the wrong place or a power beyond feature is not connected properly.
Dave M7040
