We demonstrate a clever and easy way to add air to high pressure tires on a diesel pusher motorhome using the on-board air system. With lots of modern equipment, full-wall slide-out mechanisms, tile floors, etc, newer diesel pusher RVs are heavier than ever. The front axle in particular, supported by only two wheels, places heavier demands on tires, and often requires very high air pressures as a result. Checking tire manufacturers tire pressure charts shows that the greater the weight placed on a tire, the higher the air pressure needs to be. Since the maximum air pressure available from a diesel air system is about 120 PSI, that can make putting air into your tires a challenge, mainly because the system does not STAY at 120 PSI. Truck and RV air systems are designed to routinely cycle up and down between about 90 PSI and about 120 PSI. If your tires and weight require 110 PSI, and your air compressor is currently at 105 and not running (air pressure cycle is on the way down), there is no way to get 110 PSI into your tire from a 105 PSI source. It will let air OUT of your tire instead! We demonstrate how to assemble a simple, elegant and inexpensive solution to this problem from parts available at a typical home improvement store. Be sure to confirm that all methods and materials used are compatible with your particular RV. RV Geeks offers basic DIY (do it yourself) RV service, repair and maintenance tips from full-time RVers who have been handling most of their own <b>…<b>