I'll be revising my filling methods with the new tire pressure caps, but as I mentioned the ones I have now do not have to be removed to fill or check pressures. The center of the cap is spring loaded and you just fill or check as though there wasn't even a cap.

Before that i used hex type caps and I used a deep socket and extension to reach in to the inside dual stem to remove the cap. You really need to check those inside tires. If you have a blowout because of low pressure you will tear up a lot of your coach, and possibly lose brake lines.