I've got a L3901 and BH77 with 121 hours, mostly on the backhoe. In the last 10 hours I've started getting a sound like metal on metal that ONLY happens when I extend or contract the arm. I think it's the dipperstick cylinder. All the zerks are greased and hydraulic fluid is good. Any ideas or recommendations?
Hydraulic cylinder squealing
- Thread starter dltucker
- Start date
Put a little oil on the rod and run it back and forth. I have seen seals seal too good a couple of times.
Suggest you remove one end of the cylinder and extend and retract it in order to establish that the sound is coming from the cylinder and not a tight bushing somewhere.
Dave
baronetm
Member
Equipment
L3901HST w/FEL, 3rd fnct. BH77 BH, 5' Bushhog, 6' BBL, 42" Forks, WoodMaxx WM-8H
My BH77 did squeal while retracting the bucket curl cylinder. With the tractor shut down the bucket would droop from full retract to the floor in a matter of minutes, I also could not pick up a stone with the bucket and thumb without dropping it in seconds. The cylinder would not hold pressure while loading the curl cylinder, oil was leaking by the cylinder piston packings. It turned out to be a manufactures defect in the cylinder, (about 3 hours on the hoe) scored bore that damaged the cylinder piston packings, hence high pressure oil going thru a small cut in the packing at a high velocity. This squeal could happen to any cylinder under load.
I still get a squeal from boom or curl cylinder function after the repair if exerting excessive force on the cylinders during a retract function, this is most likely oil going over a pressure relief valve, it appears to be coming from the control valve area as everything works and acts normal.
If all mechanical pivot points are fully lubed and no gravel in them grating another idea but a real long shot, you could have a kinked hydraulic line or blocked port/fitting. In industrial applications I have often heard hydraulics squeal where high pressure oil is going through a severe restriction, damaged hose, fitting, flow control. In some instances there was no noticeable difference in actuator speed or function. In the case of a damaged hose if not repaired it would not be long before a hose failure would occur.
I hope my experience is of some help, Good Luck, please let us know what you find.
I still get a squeal from boom or curl cylinder function after the repair if exerting excessive force on the cylinders during a retract function, this is most likely oil going over a pressure relief valve, it appears to be coming from the control valve area as everything works and acts normal.
If all mechanical pivot points are fully lubed and no gravel in them grating another idea but a real long shot, you could have a kinked hydraulic line or blocked port/fitting. In industrial applications I have often heard hydraulics squeal where high pressure oil is going through a severe restriction, damaged hose, fitting, flow control. In some instances there was no noticeable difference in actuator speed or function. In the case of a damaged hose if not repaired it would not be long before a hose failure would occur.
I hope my experience is of some help, Good Luck, please let us know what you find.
Bent ram is not uncommon, and can make noise.
Straightedge won't always find it. I like to remove the ram rod pin from the hoe frame, extend the cylinder most of the way out, turn engine off, get off tractor, then turn the ram rod by hand (spin it). If it's bent it'll be obvious when you spin it.
Straightedge won't always find it. I like to remove the ram rod pin from the hoe frame, extend the cylinder most of the way out, turn engine off, get off tractor, then turn the ram rod by hand (spin it). If it's bent it'll be obvious when you spin it.