I needed to replace leaking water drain line caps on my 2014 Keystone Bullet. The drain lines are Red and Blue. That means they are Pex. Only Pex parts will work. After some research I located 1/2...
I was looking for a solution to this also. I have a keystone TT and have the same caps you speak of. I like the watts solution shown above. I always seem to drop or misplace the caps.