Hello i have a question about how to check you lift arm cylinders to see if they are bad by capping the plugs off on cylinders. can somone give me some help on how to do this. not sure if it is bad lift arm cylinders or the control valve . can someone let me know the steps on how to do the checks on this to determine what is bad thanks
you could run over relief for a few then feel the cyl & see if you get any hot spots. that is a quick way to check the piston to see if it is bypassing.
im not understanding huckleberry what you are saying. please help
Raise the lift arms until they stop and keep them there. That's "over the relief", the pump is pumping oil and it's either going through the relief valve or by one of the pistons in the hydraulic cylinder, either place it's making heat. Shut it off and jump out and feel the cylinders where the piston is, if one is warm and the other is cold, then the warm one is leaking. If you pick up the front of the machine does it settle back down as fast as it would settle if you had a load in the air? Settle in both directions, in other words. For your first question. Rest the bucket on jack stands, cap the lift port on one of the cylinders (also cap the line so it doesn't leak), jack the bucket up, remove the stands and see if it holds. If either side will hold up without settling, then that cylinder is fine. Don't start/run it like that unless you know what you're doing, I can sort of explain the dangers, but I can't tell you how to do it safely.
sorry I didn't get back sooner. just got out of work. Delmer explained a lot better than I probably could have. hope you get it fixed
Thanks Delmer it only leaks in one direction it does not leak off when i lift the bobcat up. only when i have a load in bucket it leaks off or when it is just sitting there running with just the weight of the buck up in the air.
thanks for all your guys input i need all the help i can get on this one.
The easiest thing to check is holding the valve over the relief by lifting the arms all the way up and holding them there for 10 seconds. If one cylinder feels warm where the piston is, then that one is leaking. If neither feel warm, then you can cap the lines and test. There's lots of different ways to test it, you just have to be aware of pressure intensification, and how a double acting cylinder will act like a single displacement cylinder when the piston seal is gone. And the big thing is how to do it safely? Any chance you can swap the up and down at some point in the plumbing? that would be one of the safest simple ways to diagnose it further, without holding a loaded bucket in the air, climbing in and out of the machine, opening the lines and other crazy stuff.