Plumbing in a mobile home is somewhat more susceptible to breaking and leaking than the plumbing in a "site-built" house. Expense and flexibility dictate the use of plastic pipe material rather than the copper tubing often installed in a stationary structure. Newer mobile homes have cross-linked polyethylene or PEX pipe. Replacement piping, quick-connect (also called push-to-connect) couplings and specialized tools are available at any home improvement store. The water pressure itself holds the quick-connect couplings together, making a secure connection.
Removing the Broken Pipe Section
Place the U-shaped fitting of the water supply shut-off wrench over the flange on the shut-off valve of the water supply meter. Twist the wrench until the water stops flowing.
Locate the source of the leak. If it is under the home, the pipe may be covered by the under-floor insulation. Slice the insulation open with a knife or other sharp tool. Try not to slash the insulation more than necessary. You'll need as much of it intact as possible to replace after the job.
Pull the pipe away from the insulation. Cut the section with the leak (or leaks) out of the broken pipe with the pipe cutter. Be sure the cut is clean and smooth.
Go to a home improvement or hardware store and purchase pipe and couplings. Most mobile home potable (drinkable) water piping is 1/2 inch, but to be sure, take the pipe section to the store and shop for the correct-sized replacement pipe and couplings.
Installing the New Pipe Section
Trim the ends of both the old and new pipes with the pipe cutter so that all the pipe ends are smooth and straight. Be sure you leave enough length that the pipes can be fitted together easily without bending too much or crimping. Include the length of the coupling in your estimation.
Measure the length from the end of the fitting to the measurement line and mark that length on the pipe with a pencil.
Insert the PEX pipe insert into one end of the new pipe. Firmly push the pipe into the coupling up to the pencil marking. Repeat this for each end of the new pipe section.
Insert PEX pipe inserts on each end of the old pipe. Firmly push the coupling on the replacement pipe into one end of the old pipe until it creates a snug connection.
Push the remaining replacement pipe coupling onto the coupling on the old pipe. Check to be sure that all connections are snug and that the repaired section has no crimps.
Turn the water on slowly at the water supply valve. Check for any leaks or areas of strain. Ease the repaired section back up under the insulation.
Wait several hours for the insulation to dry then seal the opening in the insulation with duct tape.