Why does the air pressure drop after a few brake applications?

[Ramirez]

First, check if the brake is stuck. Observe whether the air pressure gauge shows a drop. If it does, the rubber cup might be damaged and needs replacement, or the entire wheel cylinder assembly may require changing. If there's no pressure drop, adjust the brake as excessive wheel cylinder clearance can also cause rapid air release. If air leakage is suspected, it's recommended to visit a repair shop for inspection. Brake Air Pressure: Insufficient compressed air storage in the reservoir, inadequate air supply from the brake valve, air leaks in the brake valve pipelines, or blocked air passages can all lead to insufficient compressed air pressure in the braking system during operation. When the driver presses the brake pedal in an air brake system, the brake control valve opens, connecting the passage from the reservoir to the brake chamber. Compressed air from the reservoir flows through the brake control valve into the brake chamber. Sufficient air pressure pushes the brake chamber push rod outward, rotating the brake adjuster arm to turn the cam. The cam's rotation forces the brake shoes to expand and press against the brake drum, thereby braking the wheel. Any of the above issues can reduce the pressure delivered to the brake chamber. Insufficient pressure fails to push the chamber push rod outward, preventing the brake shoes from expanding and pressing against the brake drum to brake the wheel. Air Brake: This is a braking method. In automobiles, a series of specialized devices that apply external force to certain parts of the vehicle to enforce braking to some extent are collectively referred to as the braking system.