i recently bought a 1980 40FND JLG lift from a guy needing a soleniod replaced..not a big deal.so he comes out this weekend to put the selonoid on and while testing raises the main boom as high as it would go and it would not come down.on the side of the machine are 3 manual release valves in case of pump failure.needless to say he cracked them to get the boom back down.while these manual valves were open he then raises the boom again and now i have nothing at all.no drive,tilt,telescope,steer... nothin!! my guess was he air locked the system.weird thing is the machine is equipped with an auxiliary pump wich overrides the engine pump and i still have no controls. we tested all the controls with test lights and meters and there working as they should but no responce from the hydraulic side of things.we then tried several bleeding methods and still nothing.any suggestions would be much appreciated.thanks
jay42782 what model jlg is it and what is the serial number ?That would make it easier for us to diagnose the problem.
hey tool_king! sorry for the delayed responce. Model- JLG 40FND Serial# 769310 another plate stamped below model and serial-V-947 Manufacture Date 6-1980 man i am stumped here.talked with a local service guy on the phone today and he said to start with checking dump valves.i moved a good way from close friends and family so its just me and the internet trying to resolve this issue.thanks for your time!!