I remember back when I was in High School I went on a trip to FL with a group of kids in Campus Life and the bus company we charted with had old GM's (I couldn't even try to remember or guess which models know) and the one I actually rode had a bad starter and us kids had to get out and push start it every time the driver shut it off! (which was every time he stopped because he would put it in gear to park it!)
I didn't know any better back then but now days I'd insist that bus be placed out of service! Because if the parking brakes wouldn't hold it, and it didn't need air pressure to release the brakes so about 8-10 teenagers could push start it that bus had some serious issues!
I do remember that we had about a 2 hr delay leaving s my father and several other fathers refused to let the buses leave until on of the steer tires got replaced because they "thought they could see the air inside of it!"
So just take more of yer kids friends to help push and you won't need a truck!
This is one time have that air compressor in the bay paid off, aired up and released the brakes.
I thought I had a bad starter but found out later it was a battery that only showed bad under load.
The guy in the Ford was awfully proud that he pulled off my GMC......that was until I put on the brake....