Dug out and relocated a boulder last year and the Hydraulic system started to malfunction. The 3 way front loader would lock in the uncommanded full open . It could be counter commanded but with controls in neutral the issue would repeat. I elected to service the hyd fluid hoping that would remedy the symptoms but now my hydraulics are bleeding out. Examples: the 3 way front loader bucket will not stay open. (bleeds down to closed position), the back hoe will drift out if not locked in the stow hook. Do I have air trapped in the system or do I have a auxiliary hyd component failure or ......?
JD 110 TLB Hyd Pressure bleed off
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J_J
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- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
With an open center hyd system, all valves are in series, and with all levers in neutral, hyd cyl should be locked in the last position you used.
If anything leaks down, there is a leak somewhere.
It could be leaking seals on one cyl or both.
It could be the valve spools are worn.
If you have air in the system, it will feel spongy, and if it is a little air, it will purge itself with use.
If you have a suction leak, you will continue to add air into the hyd system.
Look in your tank for bubbles. Lots of entrained air will raise the level of the hyd fluid. Check when the fluid is hot or after use.
If anything leaks down, there is a leak somewhere.
It could be leaking seals on one cyl or both.
It could be the valve spools are worn.
If you have air in the system, it will feel spongy, and if it is a little air, it will purge itself with use.
If you have a suction leak, you will continue to add air into the hyd system.
Look in your tank for bubbles. Lots of entrained air will raise the level of the hyd fluid. Check when the fluid is hot or after use.
Zebrafive
Super Member
By 3 way front end loader do you mean the two couplers mounted on the loader for a third function? Is that what is malfunctioning?
It almost sounds like a spring for centering in the valve is broken letting it shift to full open.
I am betting the new problem after the oil change is air in the system as J.J. aluded to.
It almost sounds like a spring for centering in the valve is broken letting it shift to full open.
I am betting the new problem after the oil change is air in the system as J.J. aluded to.
J_J
Super Star Member
- Joined
- Sep 6, 2003
- Messages
- 18,952
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- JACKSONVILLE, FL
- Tractor
- Power-Trac 1445, KUBOTA B-9200HST
The BH may have it's own problems, or air in the system may be affecting both the FEL and BH.
If you add a needle valve in the BH cyl that is drifting out, just pull the BH up tight and turn the needle valve to off. If it leaks down, then you probably need cyl seals.
This needle valve will provide flow control in both directions from 0 GPM to full pump GPM.
Surplus Center - 3/8 NPT 8 GPM PRINCE WNV-600 NEEDLE VALVE
If the BH stays in the stowed position, with needle valve closed, then the cyl is probably good, and the valve spools may be worn.
If you add a needle valve in the BH cyl that is drifting out, just pull the BH up tight and turn the needle valve to off. If it leaks down, then you probably need cyl seals.
This needle valve will provide flow control in both directions from 0 GPM to full pump GPM.
Surplus Center - 3/8 NPT 8 GPM PRINCE WNV-600 NEEDLE VALVE
If the BH stays in the stowed position, with needle valve closed, then the cyl is probably good, and the valve spools may be worn.