Lugboot, thanks for sharing. I think I'm going to steal this idea. I have a question though, how did you seal the hose valve connection and the presta valve in the caps? Thanks!
I used silicon sealant around the threads for the hose valve. That, combined with the washer/nut on the back side holds everything tight and sealed.
For the Presta valve stem, I cut the valve stem out of an old bike tube, leaving a section of rubber around the base. I used some spray rubber adhesive but after I did it, i needed to go back and use some silicon sealant too.
If I had it to do over again with the Presta valve, I would leave about 1/2" of rubber around the base of the stem, and then just use silicon sealant and the valve stem nut to hold everything in place and seal it.
Good luck!