Ok, DW and I took the drive back up to the 5th wheel, and bought a new battery just in case. First thing I did was try the pump switch, and it was humming (but no movement on the slides). Pulled the caps off the old battery, and I couldn't check the acid due to the water level being 1/4" below the plate tops, so I hooked up the new one. Still no movement. Went in and pulled up the bed boards and watched as my wife pushed the button. The small amount of play between the piston nuts that hold the cylinder rod to the structure showed it was moving in and out, but wouldn't move the slide. I then had her try it while watching the unattached cylinder rod on the dinette slide, and it moved in and out as she tried it. (We didn't hold the button for more than a few seconds either direction for fear of messing it up worse). So, the pump motor functions, the pump functions enough to see movement at the BR and LR pistons, but no movement whatsoever on the refer/ent. ctr slide.
I tried backing the pump "knurly knob" off 2 turns, per directions on the pump, and manually hand jacking the pump, but no luck there. I then took my silicone spray and hit all slide tracks, wire pulleys and all exterior seals, to no avail. I then rocked the bedroom slide up and down to see if it was stuck to the seals or something was jammed, had Verla hit the button while I did that, but no movement. We scratched our heads, put my tools back into the truck and headed home. I did call up the local rv repairman the park suggested, but didn't talk to him till this morning. And here's what he said-
He had been over there to do something for the lady that we bought it from earlier this summer, so he's familiar with the trailer. He also told me that he had come over and helped get the slides back in to move it out of the spot it was in to move over to the grassy area it's currently in (not an equipped parking spot, just off to the side of the circle). I told him that I was told that only one slide wouldn't close when I bought it, but none of the 3 would close for me. He said that he could confirm that 2 slides do work, but he and the park maintenance man had to give the BR a push to get it started due to it being out all summer, but the dinette slide wouldn't retract. I asked if he knew the piston on that one was disconnected (outer nut was off and the piston was about 6" from it's connection point). He said no, he wasn't aware of that, but it sounded to him like something Jess, the maintenance man, might do. But he hadn't looked at it.
Long story short, he believes the hydraulic pump is bad, even though I verified seeing the movement at the BR and loose LR cylinders. I asked if the pump has some sort of overload bypass valve, and he said he's never torn into one, since he usually just replaces them to get people on their way. I told him I've rebuilt a pump from a '65 Ford Galaxie convertible top, and thought I might be able to get a rebuild kit for this pump once we get it to the farm. He said that might be an option, because the rv pumps are about $1,100 new. But he told me if I would meet him up there on Saturday morning, he could get the slides back in so we could at least get it home and go from there.
So, this is where we stand. Right now I'm doing a search on the web trying to locate kits, videos and knowledge on the innards of rv pumps. Unfortunately, I didn't write down or take a pic of the brand pump, so I'm finding lots of pumps that don't look like mine. Oh, well, at least I know for sure that it's only one slide, and possibly not even that if I get the cylinder nutted back up. But it looks like either a new or rebuilt hydro pump. And definitely new slide seals, judging by the way a couple of them looked.
