Youare
Platinum Member
My old Ford 8N would leak down when the tractor was not running or if the 3PH was not engauged. The problem was with the 3PH lift cylinder, an internal part. The situation could be cured by replacing the "rings" on the piston if the cylinder was not scored.
My Kubota at 25 hours of use developed a condition where the 3PH would drop and raise, drop and raise a couple of dozen times in a half of minute or so. The problem thee was a metal chip in one of the relief valves, probably from manufacturing.
You could have a piece of forgein matter in a valve or a leaky cylinder. The drop rate control knob controls the rate of flow when you bleed fluid from the lift cylinder. With this valve in the closed position the 3PH my not drop at all.
One word of caution.... I replaced the hydraulic pump in I think a 750 John Deere tractor where this valve was closed and the 3PH was lowered and then the operator tried to raise the grooming mower on the 3PH. The pump was "dead headed" and it chewed itself up trying to push oil against itself.
So just becareful if you leave this drop control valve closed, I don't know if there is a relief valve in the circuit to prevent this from happening, I would hope so.
Randy
My Kubota at 25 hours of use developed a condition where the 3PH would drop and raise, drop and raise a couple of dozen times in a half of minute or so. The problem thee was a metal chip in one of the relief valves, probably from manufacturing.
You could have a piece of forgein matter in a valve or a leaky cylinder. The drop rate control knob controls the rate of flow when you bleed fluid from the lift cylinder. With this valve in the closed position the 3PH my not drop at all.
One word of caution.... I replaced the hydraulic pump in I think a 750 John Deere tractor where this valve was closed and the 3PH was lowered and then the operator tried to raise the grooming mower on the 3PH. The pump was "dead headed" and it chewed itself up trying to push oil against itself.
So just becareful if you leave this drop control valve closed, I don't know if there is a relief valve in the circuit to prevent this from happening, I would hope so.
Randy
