"Trevor Jones" WROTE: None of those single acting cylinders will likely
ever see a load in the "pulling" direction, such as when the load is moved
past the pivot point of the trailer.
^^^^^^^^^^^^^^^^^
If I understand you, you are picturing a load on the aft end of the trailer,
trying to push the bed down, and "stretching" the cylinder. Good point I
hadn't thought of. It could suck in fluid from the supply, past the check
valves. But, couldn't you stop it by just closing the control/bypass valve
between the pump and the cylinder?

Does the kit that Bruce Bergman recommends use a single or double acting
cylinder?