When checking S-cam brake slack adjusters during a walk-around inspection (vehicle parked on level ground, wheels chocked, parking brakes released), you pull hard on each reachable slack adjuster. What movement at the point where the pushrod attaches indicates the slack adjuster likely needs adjustment?

AAMVA CDL Manual, Section 5, subsections 5.3.1-5.3.2, p. 5-6; 49 CFR 383.111(b)(6)

Excess slack adjuster travel means the brake shoes aren't contacting the drum fast or firmly enough when you hit the brakes, increasing your stopping distance. Catching this during a walk-around, before you're loaded and on the road, is one of the most common real-world ways a developing brake problem is caught before it becomes a crash.