AIR BRAKE ADJUSTMENT QUESTION/ISSUE

Sounds like the adjuster is getting turned the wrong direction. When adjusting you want the rods in the chambers to come out not go in. If rods go in the shoes will stay released and not move toward drums

 

Can you take a pic of the slack you have and put a pointer on the screw you are turning? Some have 2 and one is not an adjuster. Something should move even if the slack is bad they usually will move the shoe they just won’t apply good pressure or stay in adjustment.

 

Also. If you can unbolt the tin backing plates off. Do that. Then you have an unobstructed view of brakes for future inspections. They are not really nessesary and no dot reg requires them. I know that what I just said may start an argument amongst others but even my last new truck in ‘03 did not have them.

 

Yep. You doing it right.
Is it rotating the s-camshaft when screw is turned? Look at the splined shaft the slack is on on its side and make sure it moves. If it doesn’t than the ratchet in the slack is bad. If it turns but does not turn shoes than it is something on that end. With the backing plates off you can see the s-cam end at the shoes better.

 

Were new shoes just installed? If so the s-cam my have rotated and cammed over. This will not allow the shoes to move.
Pretty common thing.

 

It is also very possible that the shoes are done and are thin enough to cause a cam over or no more adjustment. But theoritcally the way the slacks work they can still be adjusted even if metal shoe is grinding iron drum but a camover can happen because it requires a much longer stroke on the cam.