Bobcat 520 Relief value/Filter

[STEVE_NE]

By the subject line you know that I have a bobcat 520. The problem is that when it heats up. The controls for motion go dead. I can lift the bucket but can not move. I turn it off and hear gurgling noise and let set for a while and the controls start to work and move better then they've ever worked before. I have replaced the hydraulic fluid even used bobcat oil. Sucked out every drop that I could. I'm thinking that it could be the relief value sticking or some type of filter plugged.. This only happens when it gets heated up. Thanks

 

[Tazza]

It won't be your relief valve if your hydraulics still work 100%. It sounds like a blocked filter in your hydrostatic system. I'm not too sure about this machine, but i suspect it is clost to my 731, there is a hidden brinze filter in the charge line going to the hydrostatic pump. Lift the cab off, there should be like a square block sitting on the hydsraulic pump with like 5 hoses atached. On the left side there should be 3 hoses, remove the moddle one, it has a larger nut on the fitting, there should be a filter behind this, give it a GOOD clean or replace it.
Like i said, this is where it is on my 731, i am un-sure about your 520. If you have a parts manual, have a look at that section and see if there is a part hidden in that block.
If the machine squeels like a stuck pig when warm, it sounds like thats your problem (mine did the exact same thing when it got warm).