Air pressure is gone, stuck in a Monaco Dynasty

We are trying to get some air pressure in the Monaco and hooked up the compressor to the outside air chuck and took that external compressor up to 100 psi, but no air is getting into the coach system I suspect the governor or something is preventing that or maybe a one-way valve. any idea how they tow an RV fif the brakes are locked up or how they can get air into the system to get it rolling. thanks in advance