A brake that locks up is often a sign of low air pressure, an out-of-adjusted slack adjuster, or a failing s-cam bushing; thus, examine all three components, as well as the brake chamber setters and diaphragms, for the source of the problem. To put it another way, inspect the whole braking system to determine the source of the wheel locking up problem.
As a result, what should you do if your brakes become inoperable?
Keep your foot firmly planted on the brake pedal in case your vehicle’s anti-lock braking system (ABS) chooses to activate itself. Increase the pressure on the pedal by pumping it. Applying the parking brake will cause your car to slow down even more (if below 40 mph).
Additionally, what causes air brake failure is unknown. Brake imbalance may also occur as a result of mismatched brake pads.