JB6 brakes, what activates rear brake adjuster??

[masher41]

Got a 93 GMC Sierra with JB6 brakes. I've heard that different things (like driving in reverse and applying brakes, applying emergency brake, etc) trigger the self adjustment of drum brakes depending on style of brakes. Q
My question is what initiates the self adjuster on this style of rear drum brake?? Thanks for the info!! (And yes I replaced that adjuster in the pic!)

 

[Schurkey]

Duo-Servo brakes like JB6/JN6/JD6 adjust when you stop firmly in reverse, and then let off the brake pedal.

The horse-shiity 254mm (10") Leading/Trailing shoe drums adjust after using the park brake.

 

[GoToGuy]

This is also noted in the " Owners Handbook" , the glovebox edition that most owners don't have time to read.

 

[masher41]

Duo-Servo brakes like JB6/JN6/JD6 adjust when you stop firmly in reverse, and then let off the brake pedal.

The horse-shiity 254mm (10") Leading/Trailing shoe drums adjust after using the park brake.

Thanks for the info!