Exterior Sink Plumbing

[kwiebe]

Found a leak in exterior kitchen sink drain (2022 Fleetwood Flair).

Picture below of plumbing weirdness. Any idea why there is not a more direct route to the pump, from the P-trap?

The PVC seems to extend into that rectangle for no apparent reason. About 18 inches on each side. The part within the dotted line is underneath the microwave and not easily accessible.

The leak is where the flex hose connects to the pump (with hose clamps). I tightened the clamps but due to the hose type I don't think it will ever seal.

Seems like a questionable design, on many fronts. I'm thinking of cutting everything out between the trap and the pump and starting over: No hose, no grand tour underneath the microwave.

But why all that wasted pipe? There are no other connections to that pipe.

[Gary RVRoamer]

I'll hazard a guess that the extra pipe acts as a reservoir for the pump, so that it does not cycle immediately or suck air & glug as much as if it were directly below the P-trap. The pump has to be able to move the max flow from the sink taps, but most of the time it gets much less volume, so the length of pipe fills up a bit before the pump activate and sucks it away. They could have put a little tank in, but a length of PVC is cheap, easier to route, and isn't a unique part.

[kwiebe]

Originally Posted by Gary RVRoamer

I'll hazard a guess that the extra pipe acts as a reservoir for the pump, so that it does not cycle immediately or suck air & glug as much as if it were directly below the P-trap. The pump has to be able to move the max flow from the sink taps, but most of the time it gets much less volume, so the length of pipe fills up a bit before the pump activate and sucks it away. They could have put a little tank in, but a length of PVC is cheap, easier to route, and isn't a unique part.

Makes sense, thanks. They really screwed up on the hose part though.