Tractor parking brake.

All of the above.

Anything deficent between the brake chamber and the brake drum [check sometimes they are missing too] can prevent the springs [though powerful little guys they are] from applying sufficient pressure to hold.

How well do the service brakes work?

 

Shop repaired,,don't know how.

 

And it was ????

 

Don't see how misadjusted brakes would account for the intermittent delay in the park brake applying though. The pushrods will still come out at the same speed, only takes a fraction of a second to cover the extra inch of travel if the brakes were stroked right out.

 

I’m OCD about that brake. Even when I 100% know I pulled the knob, I still check it again. Lol I don’t know why but I have this thing in my head about going into a truckstop to grab something to eat or a cuppa coffee and coming back out and finding my truck smashed into the side of another truck across the parking lot. Lol probably because I’ve seen it happen.

 

why they only use one axle to hold the whole thing still