I have a 2018 JCB 8029 mini excavator that has a thumb that works fine with the auxiliary circuit light on and using the foot switch on the floor. With the circuit off the the same foot switch swings the stick right or left instead of rotating the whole house. My problem is that the stick swings fine to the right but very very slow to the left. What could possibly be causing this. It's using the same foot switch for the thumb which works fine in either direction. I have never needed the stick swing function but now I need it. Help please.
Hey Halsjcb, Perhaps we could help you out with a service manual for your mini excavator. We’re a new website only in operation the past 2 months. We are a world leader in JCB service info. We’d happily provide you with a free manual if you’d just leave your honest opinion here on the site after using it. The website is , Jcbfiles.com
Seems like directional valve or cylinder issue specific to that circuit, not the switch itself. Because switch is just sending pilot signal - different downstream valves activate depending on mode. Maybe your left side of spool is scored or has internal leakage - common on seldom-used functions. Or Left side (cap or rod) bypassing internally-pressure builds but flow leaks past piston Or Pilot line to "swing left" has restriction (kinked, debris in orifice) - weak signal = partial spool stroke Or Relief valve for swing left: Some systems have directional reliefs; left side could be stuck partially open or set too low Measure pilot pressure at stick swing valve for both directions-should be equal (~400-600 psi). If "left" is low, pilot line/orifice issue. Pressure test at swing cylinder during left command—low pressure = valve problem; good pressure but slow = cylinder seal leak. Hello @eamonn1110 welcome to HEF. Useful site & could be useful for my information blog.