Foretravel Owners' Forum

I thought my fix to a leak in our pex line running to the bath vanity sink could be of use to others.

On our last trip we had a leak that showed up as water on the floor in the bathroom coming out from under the vanity. Fortunately the rear was a little low and water flowed in that direction and allowed us to find it pretty quickly.

Turning off all water valves at the manifold I isolated it to the cold water line at the vanity sink. Unfortunately the bath vanity sink and the toilet closet sink are both controlled by a single set of manifold valves.

I took back the carpet on the bottom shelf of the vanity center and unscrewed the plywood shelf and similar in the small right side vanity cabinet. Unfortunately there was no leak under the vanity, the leak was somewhere in the floor/wall between the vanity and the utility compartment.

Water lines come from the manifold on the passenger side, over the top of the waste tanks, to the utility compartment on the drivers side. The tank fill, shower, bath vanity, and tank flush lines all take this route. At the utility compartment all these lines go up through the basement ceiling into the living space of the coach. The vanity sink (hot & cold), tank fill (single cold), and tank flush (2 lines) all travel from this point under the shower along the base about 5 feet back until they are accessible under the bath vanity.

I ended up having to cut a 3" x 6" access hole in the ceiling of the utility compartment near the outer wall. The pex lines all had 2 elbows just above the entry in the ceiling. Up, 90deg west, 3 inches, 90 deg south, 5 feet back to bathroom vanity. I had to get past the elbows to have a straight line back to the bath. Be really careful when cutting such an access hold. I used an oscillating tool and I ended up cutting 3 pex lines (sink hot cold and tank fill). As it turns out it was ok as I would have to had cut them anyway to get access the the nested elbow fittings. I used a endoscope camera to look down the lines and outside them to see if there was clearance to fish new lines. It was really tight with the water lines, drain line from bath sink and a big bundle of 120v wires all in the same run. There was no way to remove the old lines or fish in additional new ones.

I ended up running 1/4in Pex inside the existing 1/2in lines. I spliced them in at my access hole in the ceiling of the utility compartment and under the bath vanity sink. And after cleaning out my faucet screen of hard water deposits, I have better water flow than we had before. I haven't tried the tank fill as I have already added a direct to tank fill point.

I believe the leak was caused by an errant wood screw being left in the run with the water lines and electrical. Over time it wedged itself under the cold water line and eventually cut through enough for a sizable leak. I was able to see evidence of rust in one area  when I sent the camera down the line. It was near the end of the lines with the elbows. When I cut my access hole and cut out the elbows, I found a rusted screw.

A head scratcher for a while but ended up with a good outcome.

Fixes:

• Split the toilet closet sink water feed from the open bath vanity and tied into the unused clothes washer port on the manifold. Now each bath sink can be shut off independently.
• Used 1/4in pex inside the existing 1/2in pex with 1/2 to 1/4 in sharkbite couplings. This is the only way I could get through the 5 feet where the existing pex was buried under the shower floor.
• Added a recirculation valve that will direct the shower hot water feed back to the tank fill line. This was installed sitting on top of the waste tanks behind the access panels. This will be tied to a switch activated timer that we can press to pre-heat the shower water rather than filling the gray tank waiting for warm water. I still have to install the switch.

New tools:

• Pex crimp tool - get the kind that will crimp the rings. If you get the crimp hose clamp kind the clamps have very sharp edges and will not work well with lines touching each other. Sharkbites are great but take up a lot of space and are expensive. IWISS pex crimper (https://www.amazon.com/IWISS-Crimping-Cutter-Standards-Copper/dp/B01GPA36FO/ref=sr_1_2?dchild=1&keywords=IWISS+PEX-1210C&qid=1603917717&sr=8-2)
• Pex ring remover/cutter - This was not absolutely necessary but was so much faster than using a dremel to cut rings. IWISS pex ring remover (https://www.amazon.com/IWISS-PEX-1210C-Removal-2-Inch-4-Inch/dp/B00MHCDRHC/ref=sr_1_2?dchild=1&keywords=IWISS+PEX-1210C&qid=1603917919&sr=8-2)
• Endoscope camera - I don't know how I ever lived without this. I was able to feed it down the 1/2 pex and see where it was leaking. I was able to see that the pex lines were tie wrapped in and were not going to be able to be pulled out, etc. DEPSTECH Inspection Camera (https://www.amazon.com/DEPSTECH-Inspection-Industrial-Waterproof-Distance-16-4ft/dp/B086BGJ8HK)

Bruce,

Thanks for the great write-up.  Admirable problem solving.  The only thing that could have been better would have been a few pictures. 

Richard

Agree with Jan & Richard.............a few pix with that new borescope would have been great.

Here are some pictures:

001 - This is inside the 1/2in pex. It's a bit blurry but you can see how it loosk like a lot of rust.
003 - I fed the camera from the bathroom side. I wanted to make sure I was at the last elbow. You can see tie wrap end that inserted.
004 - I fed this down the passage. You can see a bundle of pex is tie wrapped to the PVC drain pipe. It was not going to come out. I saw ties every couple feet.

6274 - under the vanity sink. You can see 1/4 pex coming out of 1/2in. Used sharkbite couplers.
6305 - shows how I plumbed in recirculation solenoid valve. The extra set of sharkbite couplers is because the valve threads were leaking the first time I put it in. I cut it out used thread sealant and just used couplers to put back in rather than redo all of the fittings.
6306 - shows roof of utility compartment where I had to cut access hole. I have some 90 deg 1/4 shark bites that I may put in instead of the sweep. It may be fine as is. I will use some plastic wrap and spray in some foam to insulate and put an access cover over it.
6309 - shows small right side cabinet of bath vanity. You can see the run at the bottom with pipes and wiring. Very limited access here.