Posting pictures on the MOC isn't too difficult once you know the process. Lots of members do just that. Be sure to take the photo in Landscape mode.
Go to
https://www.montanaowners.com/forums...ad.php?t=70323 and read posts #8 and #25.
If you upload the pictures to the MOC, subsequent viewers can blow them up to a larger, more viewable size. And you will avoid the problem where the picture hosting site decides to no longer allow web forum access (Tinypic, Photo Bucket, etc.)
Pictures of your problem would help greatly to get solid answers.
You have 1/2" Pex lines in the RV. They come with clamps that hold the pipe on the fitting. You can buy a tool and clamps to install new fittings but there might be an easier way.
Shark-Bite fittings simply slip onto a Pex line with no crimping required. Pretty easy for one time jobs.
Home Depot, Lowes, Amazon, and other box stores carry Shark-Bite fittings including shutoff valves. They also have Pex lines in case you need it.