Hi Gareth,

As I recall I don't think the pump itself has a relief valve, and is totally depended on the relief valve on the hydraulic hoist control valve assembly being set correctly. I haven't any tech info now on this truck so I would screw a test gauge into hoist control valve and check the pressure setting. It needs checking anyway just to see that it has not been screwed down tight. I would set it to 1800 lbs.

Regards Nero