Water Bay woes

A few months ago while traveling I found that the hose reel ...the normal shore water connection ...would not pass water. Several years ago a check valve buried somewhere unknown failed and I added another where it was easily accessible. I assumed perhaps the old check valve had come apart and the valve pieces were plugging the line. We have a normal shore water port, so I hooked a hose to it and it worked fine for the duration of the trip. Fast forward to a few days ago when I finally got around to looking for the problem. I had taken the lower part of the water bay apart before to repair dump valves, but never messed with the upper part due to all the bare accessible water connections behind it. Now it was time.  The picture below shows the bay with both panels removed ...what fun!

Long story short, the old check valve was not the problem. I eventually found it was the two-way valve to select shore water vs tank fill. That valve (2nd connection from the right) blew it's guts out a couple of years ago and I put it back together with a new cap borrowed from another valve. The guts had come apart and fortunately plugged the valve such that the system was pressurized where I could use the pump ...had it plugged in the other position the system would not have been able to pressurize. And having the standard shore water port in addition to the hose reel was a lifesaver. The only way to put water directly into the water tank is to remove a large cap on top of the water tank in the upper part of the battery bay on the other side of the coach.

That valve is compression fit so would be a real bear to remove/replace. I gently removed the guts from a new valve I had on hand from the previous experience, gently inserted the guts into the old valve body, and reassembled. After removing the replacing the upper panel and all connections a second time to fix some leaks on the first assembly, all is working as it should.

For future reference, can someone tell me how to remove valves with compression fittings w/o destroying the existing tubing? 

I think the only way with a compression fitting is cut the tubing back and start over.

I just learned myself the hose reel had a check valve, which was bad (open).  My hose reel has a cap and I thought that was it to prevent tank water from pumping on the ground.  low and behold I found a gray PVC double male fitting marked "check valve".

You could try heating the end of the pipe with a hair dryer or heat gun. Loosen the nut, slide it back and apply heat directly to the pipe. If you cannot heat 360 concentrate on the area closest to the connection. Try to twist the pipe to break it free from the fitting and then remove.