This is a headache system, and I owned one but never had any trouble thankfully.
GM Workhorse Chassis Park Brake
Check that thread and there's a guy that is an expert on the Autopark, his email is listed.
Also use the search engine here and use "Autopark", you'll find tons of stuff.
You can disable the brake to get it somewhere to have it fixed, however you should wheel chock EVERY TIRE on the coach before you disable it. You wouldn't want it rolling over you or crashing into anything.