ok last night i used machine to lift a wall on my new shop. when i tilt the pedal back for the lift arms it will fall when the pedal is tilted back untill i nget the pedal tilted completely back. as soon as i let off the arms fall. the tilt and aux work fine. really hoping that its something simple and not the control valve. looking at the diagrams that control valve looks like a real pain. is it possible to switch the lines on the control valve between the lift and aux circuit? any advice would be great.