Explanation:

Spring brakes generally begin to apply when air pressure drops below 60 psi. This is a critical safety feature to stop the vehicle if the air supply is lost.

Explanation:

Caging a spring brake means disabling the internal spring so the vehicle can be moved in emergencies or for repair. It must be reactivated before safe operation.

Explanation:

Air brakes offer high braking force, use readily available air, and have fail-safe features like spring brakes. Unlike hydraulic systems, they continue working if minor leaks occur.

Explanation:

The application pressure gauge shows how much air is sent to the service brakes when the pedal is pressed. This allows drivers to monitor how much braking force they are using.

Explanation:

The air dryer removes moisture and contaminants from compressed air before it reaches the tanks. This helps prevent corrosion, freezing, and sticking valves, especially in cold weather.

Explanation:

Relay valves allow air to reach the brake chambers more quickly by positioning them closer to the wheels. If they fail, brakes may respond slowly or not at all.

Explanation:

Brake chambers must be securely mounted with no signs of cracks, dents, or air leaks. Damage or looseness can result in reduced braking power or brake failure.

Explanation:

If left caged, the spring brake cannot apply during emergencies or when parked. This disables a key safety feature and is highly dangerous on slopes or during air loss.

Explanation:

When spring brakes are caged, they cannot apply during a failure or parking situation. This disables a key safety system, making the vehicle unsafe to operate.

Explanation:

A wrench or socket is used to turn the adjusting bolt on manual slack adjusters. The adjuster should be tightened until the brake linings contact the drum, then backed off slightly as per instructions.

Explanation:

Relay valves allow air to reach the brake chambers faster by using a local air supply. This ensures quick and even brake application, especially in long vehicles like tractor-trailers.

Explanation:

The foot valve regulates the amount of air sent to the service brakes. Pressing harder increases air pressure in the brake chambers, resulting in stronger braking.

Explanation:

Staggering brake application helps control vehicle stability by allowing different axles to apply slightly later or earlier, depending on load. This prevents skidding or jackknifing.

Explanation:

Any air leak, especially a major one, can quickly reduce system pressure and lead to brake failure. Stopping the vehicle promptly ensures your safety and prevents brake system damage.

Explanation:

Heat reduces the ability of brake linings to generate friction. This is called brake fade, and it results in longer stopping distances and the need for harder braking effort.

Explanation:

If spring brakes are caged (disabled) or damaged and not repaired, they will not apply when needed in emergencies or when parking, posing a major safety risk.

Explanation:

Automatic slack adjusters adjust pushrod stroke within set limits as the brake linings wear, ensuring consistent brake performance and reducing inspection frequency.

Explanation:

Brakes that remain partially applied cause heat, reduce fuel efficiency, and wear out components prematurely. This often indicates improper adjustment or return spring failure.

Explanation:

A leak or malfunction in the primary system would result in pressure loss in that tank, while the secondary tank may still maintain pressure due to system separation.

Explanation:

The foot valve (or treadle valve) releases compressed air from the tanks to the brake chambers. The more the driver presses it, the greater the air pressure sent to apply the brakes.

Explanation:

Using a lower gear and auxiliary brakes (like engine retarders) helps control speed and reduces service brake use. This prevents heat buildup and brake fade.

Explanation:

Using the wrong slack adjuster type can lead to improper brake function. The replacement must match the original specifications to maintain stroke accuracy and brake force.

Explanation:

The governor monitors air tank pressure. When it falls below the cut-in pressure (usually around 100 psi), it signals the compressor to start filling the tanks again.

Explanation:

Spongy brakes may indicate air leaks, low pressure, or water/oil in the system. The cause must be diagnosed and corrected before the vehicle is operated further.

Explanation:

Spring brakes automatically apply when air pressure falls below a safe level or when the parking brake control is activated. They ensure the vehicle cannot move without air.

Explanation:

To test spring brakes, release them, then pump the service brakes repeatedly with the engine off. The pressure will drop, and the spring brakes should apply automatically below 60 psi.

Explanation:

A properly adjusted slack adjuster will show pushrod movement within acceptable limits (usually less than 1.75 inches, depending on chamber type). Anything beyond that requires adjustment.

Explanation:

Mismatched components can cause some brakes to apply harder or sooner than others, leading to skidding, wheel lockup, or loss of control. Brake systems must be balanced for safe performance.

Explanation:

Fanning the brakes repeatedly causes heat buildup and rapid air loss. Instead, use a steady brake application with engine braking to maintain control and system pressure.

Explanation:

If brakes are adjusted too tight, they might not fully release. This causes drag, overheating, increased wear, and potentially brake failure during long use or descents.