We have been experiencing a steady decline in hydraulic power in several of our skid steers. They are 246A and 272A models, all with 4-6k hours on them. Engine runs fine, and there is no mobility problem. But the boom and tilt functions are sluggish and lacking in power; even with the throttle maxed the machines have difficulty lifting any kind of load. We do clearing jobs, so our primary implement is 20" shears, and the machines that are having this problem take 5 times as long to cut a tree as a machine that is running properly(if such a thing exists). Cutting large trees is impossible. We've been running these units 7-8 hours a day for years, and since we're always cutting, the auxiliary hydraulics are in constant use, all day, every day. We're figuring it is probably a problem with relief valves. But, before we start taking units out of the field and raising cabs and yanking valves, I thought I'd post here and see if anyone had any other suggestions, advice, or prior experience with this type of problem. Thanks!
I would not think the relief valves are going to be your problem with several machines of the same vintage having similar problems. I'm not sure what cat offers in the way of on board diagnostics on the mentioned machines if any. 4-6K hrs is getting up there for a skid steer, I would be doing what it takes to verify pump performance before yanking valves.
Ok...but I'm pretty sure the relief valves are engaging at the point of failure. I can hear it. I meant to say that in the initial post, sorry. But...those valves are supposed to be calibrated to open at a high pressure, right? So if the valves are working correctly, the pump should be ok as it is generating a pressure high enough to trip the valve. That was my logic, anyway...I could totally be wrong.
Well I'm not going to say you logic is incorrect but just because a pump puts out the pressure does not necessarily mean the volume(speed) is there. Put a gauge on aux. circuit, should be easy enough. Then put it on lift or curl circuit and compare to spec.
Ahh I see. Ok, will do that. Thanks!