Hey guys I am working on this machine Case 580SM series 2 pilot controls ser.#N4C306330 The backhoe functions get slower as the machine heats up. Notice it mostly in the boom lift. when you activate any other function just a little the boom stops totaly. otherwise it is just very slow even at 2000rpms. Also the stabilizers do not lift the weight of the machine unless you rev it up good. i checked the pressure at port 1 on the pump, and the loader main relief is good at 3100psi, and the second stage is good at 4000psi. I also checked the load sense relief on the backhoe valve and it is at 2600 psi, tried to increase it by turning the adjustment but it does not raise the psi. I checked the pilot pressure and it seems alright at 500psi. I dont have a flow gauge to check the flow of the pump. Could it be the pump just not capable of creating enough flow even if the psi shows right?
Possibly a restriction somewhere. I'd be looking for debris in the lines, maybe sacrifice a filter and have a look inside too.
would that get worse as it heats up? When it is cold it isjust so noticibly slow. stabilizers are weak at idle and boom up is slow compared to my other 580sm
As fluid warms up, viscosity decreases, making leaks and bypasses easier. That may point to the pump, but you should always begin at the beginning. Check flow rate by pulling a line and filling a bucket while timing, if necessary. You don't really need anything but time to do that. It definitely sounds like there is a problem. My Ford 555D can pretty much do all its work at nearly full strength at an idle if I want to, just much slower that way.