Mysterious leak-It leaked,now it doesn't?

[shinybean]

The last time I went camping, I had a fairly strong water leak in the line that leads from the fresh water tank to the pump. (enough to make water run out onto the ground at the belly pan) It was coming from a hose/pipe clamp patch in the line. Here's the thing: I was connected to the city water, had no water in the fresh water tank, and the pump was not turned on at any time during the trip. This line seems to be isolated from the rest of the system by the pump, but the leak stopped when I turned off the water supply. I thought it was strange that that was the only place it was leaking, but I just turned off the water for the remainder of the trip. When I got home and re-connected the water to see what pipes needed to be repaired, there was no leak. Does anyone know what could have caused this leak? I do have the original bell shaped pressure regulator installed as well. Thanks!

[azflycaster]

If the line to the tank was leaking, was the tank filling with water as well?

What it sounds like is:
The water pump has a check valve that prevents water from flowing backwards through it when connected to city water. If the check valve might have not sealed correctly because of dirt or some other reason. When you removed pressure and then tried it again, the valve sealed correctly.

This is just a SWAG, it could be anything.

If it is correct, you should have some water in the tank and the line still has a leak, but you may not see it because when you use the pump you have no pressure in that line.

[shinybean]

Thanks Richard! That sounds like what it could have been. I am in the process of replacing the line with PEX anyway. I didn't want to risk the leak reappearing when we set up camp - it seems that's when problems like to happen... We'll see what happens when I get everything re-connected.

Are those check valves easy to find replacements for? I also have some other sort of valve in that same line that drains out of the trailer. It has 60 PSI stamped on the top. Is that some sort of pressure relief valve? I'll try and post some pics tomorrow.