Waldon 5000 loader with backhoe

Hi have a Waldon 5000 and having a problem, runs great works good but when it idles for any time will start to stall out unless you start to use the machine, ie move bucket lift curl what ever then runs fine again till it idles then starts stalling again. I have done all new fluid and correct filter some new hoses. Just can't figure why it does this. Will work fine as long as you are doing some thing. Seems like the pump is building pressure at idle. Help. its a great little machine.

Waldon 5000 loader with backhoe