Ever since I winterized my Roadtrek in Antwerp prior to putting it on the boat back to America, I have had an annoying slow leak at the city water connection, the fitting where you attach the hose when you're hooked up to city water. Part of the winterizing procedure is to pop the check valve and let some water drain out of this connection, which is when this leak started. I had my Chevy for years and never had a problem with this valve, but the thing is, I NEVER hook up to city water in my new Sprinter Roadtrek, always using the gravity fill, so this valve has had months to sit in one position and corrode. Which it did. Once the seat is corroded, the check valve leaks, there's a steady drip outside, and the water pump comes on every 15 to 30 seconds. Most annoying. Time for a new valve.
Rather than make an appointment at an RV repair facility and wait, I ordered the part – $16 on Amazon. Now all I needed were the special crimpers PEX plumbing uses to attach PEX line to the fittings. I found a crimper for $30 on Amazon, and was glad to get it – you never know when you may have to do some emergency plumbing repair, and now that I had this crimper and some stainless steel clamps, I could replace every connection in my Roadtrek. That's peace of mind on the road.
PEX stands for cross-linked polyethylene – it's a flexible tubing that is commonly used in RVs instead of the slightly cheaper PVC or CPVC used in sticks and bricks houses. Flexibility means it's more resistant to impace and vibration, which stationary applications don't have to worry about, but RVs do. Metal like copper tubing is great, but way too heavy for RV usage unless you have a 26,000 pound bus chassis and don't care how much you weigh. If you want light and flexible, PEX is the tubing of choice. Connections with PEX are made with this special crimper and stainless steel clamps. There's also a Sharkbite connection system with copper doughnuts, but it's twice as expensive as the stainless steel clamps, which are crimped to a specific tightness by the special tool which I now have.
Brandishing my new crimper, I set out to work on the leaking valve. First order of business was to drill out the pop rivets holding the flange of the valve to the sheet metal bracket it's attached to. (A pop rivet gun is another indispensible tool when you're working on Roadtreks, about $20 at Home Depot or Lowe's.) I used a screwdriver to pry off the old PEX clamp – they come off easily if you know where to pry. There's a little tab sticking out on the side of the clamp that tell you where to pry up and pop the clamp open.
Taking the old valve out and comparing it to the new one, I discovered that I had a slight problem – I had inside half inch pipe threads on the old valve and outside threads on the new valve where it attached to the barb, the part that slips inside the PEX tubing to be clamped. Not a big problem, though. Twenty minutes and 76 cents later, I was back from Home Depot with an adapter with inside threads on each end, which connected the new valve and the barb easily. A little teflon tape and some careful tightening, and I had the new assembly ready to install.
I trimmed the PEX tubing so I'd have fresh pipe to crimp, slid the clamp over the tubing, and the barb into the tubing. Shade treeing means my Roadtrek was flat on the ground with limited space, but the flexibility of the tubing allowed me to move it so that I could find an angle where I could open the jaws of the crimper wide enough to start the crimp and still grab the clamp. You can't do that with PVC or metal. It's an idiot proof system – there's a racheting mechanism in the crimper so that it won't release the clamp until you crimp it completely.
Almost done – I screwed the barb and attached connector into the back of the valve, again using Teflon tape on the pipe threads, and pop riveted the assembly into place. I turn on the water pump, and – nothing. No drips, no leaks. I am happy. I hated having to turn the pump off and on every time I needed water, that's more work than I'm used to doing. I think I'll take the rest of the day off.