Michigan CDL DMV Air Brakes 1

If a vehicle is equipped, an application pressure gauge shows how much air pressure is being applied to the brakes. This gauge can help a driver identify if their brakes are beginning to fade.

In a vehicle with air brakes, the brake lights are activated when the brake pedal is pushed and air pressure moves an electric switch. With the application of air pressure, the switch will then turn on the brake lights.

The low air pressure warning signal must activate before the air supply pressure drops below 55 psi in the air tank. If the warning signal does not turn on when being tested during an inspection, the vehicle is not safe to drive.

If you need to make an emergency stop, you can use either the controlled braking method or the stab braking method. It's important to brake in a way that keeps your vehicle in a straight line but will still allow you to turn if necessary.

Most newer heavy-duty vehicles use dual air brake systems. A dual air brake system has two separate air brake systems which use a single set of brake controls.

Friction inside a brake drum is caused when the brake shoes and linings push against the inside of the drum. The friction in the drums will slow and stop the vehicle.

When pressing the brake pedal in a vehicle with S-cam brakes, air will enter the brake chambers. The added air pressure will push out the rods and move slack adjusters, twisting the brake camshafts.

Brakes are particularly prone to getting out of adjustment if they are hot. Be sure to routinely check the adjustment of your brakes. For a vehicle to be safely controlled, all brakes must be properly functioning and adjusted.

When performing a static leakage test on a triple combination vehicle with air brakes, the leakage rate should be no more than 5 psi in one minute. If the air leaks from the air brake system at a quicker rate, the vehicle should not be driven because something likely needs to be repaired.

The air compressor of an air brake system is connected to the engine through gears or a v-belt. The compressor may be air-cooled or cooled by the engine cooling system.

Before driving a vehicle with a dual air brake system, allow time for the air compressor to build up a minimum of 100 psi pressure in both the primary and secondary systems. Watch the air pressure gauges to monitor the pressure levels.

An air compressor governor will stop the compressor from pumping air once the air tanks are at an air pressure level around 125 psi. This air pressure level is referred to as the "cut-out" level.

Check each slack adjuster after parking on level ground, setting wheel chocks, and disengaging the parking brake. Pull the slack adjusters to make sure they do not move more than about one inch from where the push rod is attached. If they move more than one inch, they may be out of adjustment and will need to be fixed.

Many large CMVs are equipped with air brakes. An air braking system uses compressed air to operate.

The air storage tanks in an air brake system store compressed air to be used for braking. They hold enough air for the brakes to still be used several times if the compressor stops working.

Brakes out of adjustment will fade before those that are properly adjusted. Brake adjustment must be checked frequently to help prevent brake issues.

Both systems in a dual air brake systems share a single air compressor. If the air compressor is damaged, neither system will be able to operate properly.

Compressed air in an air brake system usually contains a certain amount of water and compressor oil. The water and oil can damage the brakes if left to accumulate in the system. Tanks must be drained regularly to remove this build-up.

In a dual air brake system, either the front or rear brakes will not be fully operable if one of the air systems gets too low on pressure. If the air pressure in either tank gets too low while you are driving, you should exit the road and park as soon as possible.

When parking on a level surface, you should use wheel chocks. If the vehicle is not equipped with spring brakes, this is essential to prevent the trailer from moving.

While driving downhill, you should hold down the brake pedal until your vehicle reaches a speed 5 mph below your safe speed, then release the brake pedal. Repeat this process.

Compressed air in an air brake system usually has a certain amount of water and oil in it. This can harm the system if allowed to accumulate. Air tanks have drain valves to aid in removing water and oil from the compressed air.

On vehicles with Anti-Lock Braking Systems (ABS), yellow malfunction lamps alert the driver to ABS malfunction.

A dual air brake system is made up of two separate air brake systems. The systems share a single set of brake controls, but each has its own air tanks, hoses, and lines. One system typically operates the regular brakes on the rear axle or axles while the other system operates the regular brakes on the front axle.

Drum brakes are attached to the wheels and located on the axles of a vehicle. The braking mechanisms that cause the vehicle to stop can be found inside of a drum brake.