[Jack Houpe]

Please correct me if I'm wrong but isn't there only 1 ram on the rear slide? If the top comes out that means the locking pins have retracted so I would take a lucky guess and say its one of the valves on the HWH system for the rear slide. I think there are magnetic reed switches on the locking pins that if both have not retracted the pump shouldn't even come on for the main ram, if its coming on then once again I think its a stuck valve up front.

My GUESS