Need Suggestions..Bus will not start/stay running

[gumpy]

That's probably more likely, unless your bus holds air in the aux system better than most. If I understood you, it was 3 weeks since you first had the problem. If it were the safety system, and there was no air, it would have reacted the same way it did before, by starting and then slowly dieing as the air built up. If the air was down today, and it still wouldn't start, it's probably lost it's prime.

craig