Fixed problem. /forums/images/graemlins/grin.gif Removed valve pictured in the attachment, pulled up on lift arms to apply pressure to system. Squirted out some oil and the bullet shaped seat, cleaned seat and replaced. Works like a charm. Now I can lift the lift arms by hand, which I could not do before, this allows system to float as I think it should. Really simple fix. Thanks for everyone's help! Much appreciated. /forums/images/graemlins/grin.gif /forums/images/graemlins/grin.gif