I don't know if this problem exists in other places besides the Safari-based Montereys, but I recently had a problem that was fixable but a real PITA. Beaver used some massively heavy and stiff white plastic hose (its available at home depot - some kid of pool hose) to connect the sink drain to the grey tank. it slinkys under the slide-out. it is hose clamped to two large barbed fittings.
On a recent trip we started seeing water come out from under the slide on the OUTSIDE of the coach - the hose had split at the sink fitting because it wasn't long enough so it was constantly stressed and unless the coach is way off level it will drain to the outside. After pulling out all the drawers and slides it was obvious what the problem was. There was a lot of nastiness from food particles in the sink water that had to be cleaned up.
Easy to see didn't make it easy to fix however. This was one of those things that was put together before the rest of the cabinetry was added. Had to work laying on the floor on my back reaching over my head and relying on feel, and for the most part using only one arm with the bottom of the cabinet digging into my shoulder while other parts abused my forearm. There is no way to replace the white hose with identical material. It requires an enormous amount of force to drive onto the barb and there's no way to get that force in the positions you are in. if you put it on the barb first, you'll never get the threads lined up to get the fitting in, and even if you did, the hose won't allow it to rotate to screw the fitting in and you still have to deal with the other end somehow.
Solution came via a pool supply store. They have fittings to allow the use of that grey corrugated pool vac hose. It's extremely flexible and took about a tenth of the time to install than it took to remove the white hose.
