Installing a residential kitchen faucet into an older coach

January 14, 2012, 10:18:23 am

Greetings once again,

Been very busy on the coach of late, despite the temperatures. The latest "this should be straightforward" project was installing a new Delta faucet in the kitchen. The 20 year old original Moen was beyond salvage and had to go.

There is nothing simple or straightforward working on a motorcoach. Every little thing has surprises for you to discover and resolve along the way. Every day working on a coach is a character building day.

First off is the polybutylene tubing. Was nice to find Sharkbite makes adapters to connect poly to pex.

Looked at RV faucets for a long time, but it was clear nothing was around (that I liked) to connect directly to the existing water lines without modification. So I turned back to residential faucets and finally ended up with a great deal on the same Delta Linden faucet as in my stick and brick, except in stainless. The two things I like the most about this faucet is the pull out locks in solid when put back, and it stays on the spray setting regardless how low the flow is. Much more efficient than the old one.

All their faucets come with preterminated lines at the faucet end (actually, most all faucets come that way now). For an RV installation, the lines are way too long, but can be cut and a new connector put on (if you order the kit to use the compression fittings). The instructions indicate that the lines are compatible with 3/8 pex connectors, so that was the route I chose to go.

The next surprise came when I pulled the old faucet and went to install the new one. The holes in the Corian counter were 7/8 diameter - and I needed 1 3/8 diameter holes. How to enlarge existing holes? Simple - get a hole plug the same diameter as the existing hole - I used those pop-in metal caps for plugging unneeded holes in electrical panels (Home Depot electrical section). Drilled a hole in the center of the cap, popped in the cap, then used a regular bi-metal hole saw to cut a new hole. Faucet went in just fine.

When I pulled the water heater, I redid the hot and cold lines running up the side of the cabinet, with pex conversion fittings, and ran pex tubing from there. Bought 1/2 to 3/8 sharkbite reducers and figured that was it. Then I cut the supply lines to the faucet and went to fit the reducer. No go. The line was too small.

After some carefully chosen profanities were uttered, I measure the supply lines and found their outside diameter was 3/8. However, 3/8 pex line measures 1/2 inch outside diameter, with a 3/8 inside diameter. We have a problem here.

As I have installed a reverse osmosis system, I am very familiar with and a big fan of John Guest fittings and lines --> John Guest - The World Leader in Push-fit Fittings, Pipe and Plastic Plumbing . They have the same pressure and temp specs as pex, brass and copper, however are not metallic and won't corrode. They also assemble with a push fit and are reusable (cheaper than sharkbite as well). Most online water filter outlet stores carry these.

I grabbed a couple of 3/8 JG connectors, and lo and behold - that fit the faucet supply lines. Now I needed to connect the JG connector to the pex tubing. The solution came in the form of a female 1/2 inch sharkbite female NPT elbow, and a 3/8 JG adapter with a 1/2 NPT end. Also adding JG shutoff valves to both hot and cold lines, and a tee in the cold water line for the water filter. JG adapters with 3/8 NPT ends work here as well.

In the end, I had to go from poly to pex to john guest to make this work, but the end result was worth it. Still need to make a 3 inch hole in the under sink shelf for the pull-out line to go through, but almost done.

Steve

Re: Installing a residential kitchen faucet into an older coach

Reply #1 – January 14, 2012, 11:19:54 am

Plus one on the character building aspects of working on a coach! Nice job, thanks for sharing.... That is another of the projects on my list.
Don

Quote from: Merle Hench – January 14, 2012, 10:18:23 am

There is nothing simple or straightforward working on a motorcoach. Every little thing has surprises for you to discover and resolve along the way. Every day working on a coach is a character building day.

Re: Installing a residential kitchen faucet into an older coach

Reply #2 – January 14, 2012, 01:03:40 pm

Boy, you just don't mess around when it comes to working on your RV. Awesome. Thanks for the write-up and the pics.

Craig

Re: Installing a residential kitchen faucet into an older coach

Reply #3 – January 16, 2012, 05:36:47 pm

Thought I'd close up here with some pics of the completed plumbing.

Drilled a 3 inch hole in the upper shelf below the sink, and ran the pull out hose with weight through there. Works just fine, unless it you pull it out all the way, where it ends up halfway to the floor - in which case, you need to work the weight back through the hole. I bridged the poly to pex above the water heater, while the heater was out, then used that elbow with adapter from there. I had shut off valves on hand so added those in.

Instead of looping all the tubing attached to the faucet, I cut it to length then used a John Guest elbow on the hot water line to run across to the pex adapter. On the cold water line, I used a tee, tapping off from there to the water filter inlet. I used jg fittings there as well, running a 1/4 inch line to the filtered water faucet above.

Still working on completing the water heater installation...

Steve

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