[RickandJanice]

I think Ron's response is correct. With two way Hydraulic systems there is usually a pressure and a return line. Depending which order valves are opened in the solenoid as to which line is which. As fluid flows in one line to move the ram, the fluid on the other side of the ram needs to flow out, or the ram will not move. If you tie the wrong lines together or reverse them on one circuit, the fluid on both side of the valves equalize and the valves cannot open. This is basically what happened when you tied the two lines together on the the bed lift, so is probably affecting the whole system.

If it was just air, the slides would work but would jerk as the air bubble move through the lines. If that is the case, air can be worked out of the system by running the slides in and out in the correct sequence until the air is pushed back to the reservoir. You may still have to do this after plugging the lines to the lift individually. Run out bedroom first, then kitchen then living room. Run in in reverse order bringing the bedroom in last.