Hi, I have a JCB 803 mini digger (2002), there seems to be a problem with the hydraulics in that the movements of boom and dipper become very jerky unless you are very very gentle with the joysticks, to the point that unless you release the joysticks the machine rocks on it's tracks. Any help appreciated.
I would start by checking hydraulic pressures first and the servo pressure as well as this may be set to high if you back the throttle off does it improve the jerky hyds.
Hi, thanks for reply. I'm away from the digger at the moment so can't do any checks, but effects are reduced with less throttle. I can also hear a clattering kind of noise from beneath the cab floor, is there a pressure control valve or something in there that might be faulty or sticking ?
Is the clattering noise from the hyd pump area?
No, the pump is alongside the engine in an open space and was a new pump fitted when I bought it as the old one came in a box. The noise seems to be from under the cab floor and is there when engine running and no hyd load. When I get back home I will investigate more thoroughly. Thanks.
That noise is possibly hoses rubbing on the cab floor plates and even the floor plates loose i would say or something possibly under the seat vibrating. The harsh hydraulics would point to the servo pressure perhaps to high .
Hi again, been a while since I posted this but I have made some progress since then. I found the clattering noise under the floor, it was a hydraulic pipe vibrating against the framework of the floor area. Next problem, the jerky hydraulics. I have ordered a hydraulic test kit which is coming next week, any advice on where to test for pressures and where is the servo located for adjusting ?