I tried to see if this has been covered, perhaps missed it, and it hopefully is very rare...but the temporary fix worked and you may want to know about it. Might apply to many areas, but for me the inlet water line to the water manifold is "plastic" hard pipe, like a pvc or such, and it developed crack (thus leak). You can temporarily stop that type of leak by cutting off an inch or so piece of garden hose and then cut that piece along the length direction. Wrap it around the cracked "pvc" and then secure it tightly with a hose clamp (one of those metal clamps with slits cut along the metal). I went that way for several weeks, not a drop of water, til I could spend more time working on it. So I carry a few of these clamps along now. A friend showed me that trick, thanks Don Cox. Mike
Check out Sea Tech fittings for repairs to pex tubing.
Thanks......Here is the web site you referenced for pex, SeaTech Fittings - Quick Connect and Thru Hull Fittings - FreshWaterSystems.com (http://www.freshwatersystems.com/c-282-seatech-fittings.aspx?gclid=CPPcoIeD560CFahgTAodFGL-Ww)
I think the repair I had may have been, or not, pex. But in my breakdown in losing our water supply I did not have the pex materials so the hose patch was great. That leads me to thinking, I might get some pex fittings to carry along with me that I or someone in an RV park could use if they need. Mike