Last fall I had the under belly open on mine while putting on discs and I fixed every inferior thing I saw. I think it's the frame mfgr that does all the tank install and plumbing below the floor and it also seems to be common practice for them to use plastic barbed fittings and hoses that aren't full sized. My tank vent, drain and suction were all 1/2NPT threadolet connectors, plastic welded to the tank but then they were choked down with plastic barb adaptors and the 90s were the square throat type. I redid it all with 1/2 NPT plastic fittings and used 1/2" cpvc pipe for the vent so it will never have water traps in it again. The most interesting thing I found was a tiny in-tank strainer at the suction connector. It wouldn't take much of anything to plug it and shut down the suction and I didn't want to tear into the bottom again, so I used a drill bit to hook on to that strainer and I pulled it out of the tank. Then I added a suction strainer on the pump where I can service it. Check out all that stuff, if they have the belly open long enough. Craig
