We have just returned from a trip, and I went to re-winterize the trailer and it would not suck up the antifreeze like it has done before. I added water to the freshwater tank and set the levers correctly and it wouldn't pressure up to any faucet. I could hear it running, but very quiet compared to normal. I have assumed the pump is out, most likely the diaphragm. Anyway, I located the specs and a replacement pump but I can't seem to find anything that tells me where it is located and how I get to it. Any help would be appreciated before I start guessing.