Originally Posted by perrybpilot
New shower faucet assembly fixed the problem. It was cracked in the crossover line.
I de-winterized my 2014 38FL this weekend and discovered what sounds to be the exact same problem - even though I had thoroughly winterized the rig. I discovered I had water leaking from under the shower floor while running fresh water through the lines, clearing the pink stuff. I then saw the water appeared to be running down the wall on the back side of the shower wall after looking through the access cupboard at the back of the heater. I ended up having to remove the mixer faucets from the shower and found the leak coming from an almost invisible crack in a black, T shaped valve that mixes both hot and cold water before forcing it up the flexible pipe to the shower head. Fortunately, we always start the season by camping at a golf/rv resort in the same town as the dealership, so I called in there, armed with the full faucet assembly, looking to purchase a new set. What I discovered, thanks to the service manager (off duty but buying gear for his own trailer) was the small black mixer valve could be purchased and switched out rather than having to spend nearly $50 on a new faucet set. In actual fact, he switched it out there and then for me and then didn't charge me the $4 for the valve. He said he could loose that cost quite easily. I took the original faucet with the new mixer valve back to the trailer and installed it back in to the shower without too much trouble - just a little tight working space with just enough room for fingers and a wrench to tighten the pipes back on the faucet assembly. Sealed it with some clear marine grade silicon sealant and tested her out. No leaks, drips or floods so now we're all good.
I did thoroughly winterize with RV antifreeze but this year we had prolonged periods down to -40oC (-40oF). The hard, plastic mixer pipe/valve still split, even with this fluid having been run through.
Here is a link to the faucet set I have. The cracked plastic mixer tube/valve is behind the nickel coloured cover but attached to the small, black threaded piece in the centre. This piece is what attaches to the flexible shower hose.