I made a simple newbie mistake a while ago. It's one that frustrates me because it's very easy to do and looking around the web it seems to be common, but the RV manufacturers don't seem to have a good solution. I'm hoping that with this post I can educate others to avoid the mistake, or to recover if necessary.
The mistake in question: the city water hookup has a little check valve. If you press in the valve while there is pressure in the system, you can damage the valve.
As part of winterizing, if you're not using compressed air, you should (after you drain the rest of the system
) press the check valve in. Otherwise surface tension can hold a bit of water in your city water line. But don't do it when the system is pressurized!
Specifically, there is a little rubber O-ring on the check valve. If you press the valve in while there is pressure in the system, this O-ring can become unseated and won't seal properly. From that point, when your system is pressurized, the city water hookup will leak.
I asked Reace about repairing this, and his response was that these are sealed units and aren't repairable. I wasn't happy about that answer, but it freed me up to experiment. It seems at this point that I did successfully repair the problem.
OK, here's the city water hookup:
with cap removed:
and with the detritus screen removed:
That white plastic thing inside is the check valve. There's a white plastic valve stem, with an O-ring held against the inside of the valve by the spring you can sort-of see in that photo. The spring is held on with the white plastic cap press-fitted onto the valve stem.
My mistake was to press in the valve stem while the system was pressurized. Don't do that
. That's the first thing you should take from this post. Completely drain your system before you touch that valve stem.
But if you do, you may find afterwards that your city water hook leaks when you have your pump turned on and your system pressurized. The problem is that the O-ring I talked about has become unseated.
I use a pair of needle-nosed pliers and judicious (careful!) force to remove the white plastic cap. Here's the cap:
And here's the valve with the cap removed. If you look carefully, you can see the problem:
Here's the problem: I've pulled the spring out. That O-ring isn't supposed to be there:
OK, so what next? I tried re-inserting the O-ring at this point, but had no luck. I managed to get it pushed back into the valve, but it wasn't seated properly and the best I could manage was a slow leak.
To effect a true repair, I needed to take the valve apart. The forum limits me to 8 pictures in a post, so the repair follows in the next post.