Allright guys, it's been a long time and I'm sorry for the delay. I lost my original account in the gmail purge, so I also must apologize for any missing information.
Ultimately the bus had a lot of things that needed attention. The brakes had a couple things going on: the sensor in the back was leaking (an easy fix) and the stoplight switch under the brake pedal had somehow snapped in half. Fixing those issues led to the warning light and buzzer ("Park E Brake" light) no longer being stuck constantly on, same story with the brake lights. We also had to replace the bus batteries and all four rear tires, all of which make me feel a lot more confident in our machine.
The brake issue has progressed though. The bus is on a Lucas-Girling system and our backup electrical brake booster is not engaging. Instead, in situations where it should (e.g., key in, engine off, brakes applied) the "Park E Brake" light comes on and there is no sound, much less the backup engaging. I'll be checking the power supply this weekend and running down the troubleshooting list in my shop manual, but I wanted to see if anyone here had experience with or any insight in regards to the problems we've run into.
Also, since this thread has a distinct lack of pics, here is our Barge:
by The Janky Barge
, on Flickr