The buses are heavyweight and require more braking force to stop them at different destinations. The air brake system is efficient because it has more stability and efficiency at various speeds.
Do Buses Have Air Brakes? Buses have air brakes to withstand heavy loads, improve the safety of large vehicles, smooth and gradual braking, continuous airflow, and no leakage-related failure.
Air brakes are beneficial because they are more durable, with minimum internal cracks and damages. They are large vehicle specific and facilitate maximum performance at high speed.
Why do buses have air brakes?
These are effective brakes that use compressed air for their optimized functionality. All small to large school buses comprise them, due to the reasons below.
Withstand the heavy loads
School buses are heavy vehicles with an average weight of about 28000 to 35000 pounds (14 to 17.5 US tons). Therefore, they have air brakes that use compressed air to withstand heavy loads and gross vehicle weight rating.
They can withstand these weights without internal or surface damage. Also, they have compression of air, which can stop large and heavy vehicles without internal damages and restrictions.
The load has minimum effect on their performance, and they remain stable for thousands of miles without significant damage.
They are safe and reliable according to their layout and overall efficiency. The manufacturing companies install them in heavy buses to withstand the passenger load and gross vehicle weight rating (GVWR).
Improved safety of large vehicles
Bus manufacturing companies install air brakes in them to improve vehicle safety. Moreover, they increase the safety level of all travelers.
Buses do not lack the power and braking force during different driving conditions. Also, they are specific brakes that can produce more pressure and enough force it stops a heavy vehicle without vibrations and sudden shaking.
They provide maximum safety to children by increasing their protection during stop conditions. The braking force is stable and prevents the sudden rolling of the bus and passengers forward.
These large vehicles remain stable despite the heavy loads of cargo and passengers. You can safely stop your bus at different stops.
They have complicated layouts according to the stock standards.
Smooth and gradual braking
Heavyweight and large-sized vehicles require smooth braking. Air brakes provide smooth and gradual stopping.
However, they utilize compressed air, which can push the piston. Then, they produce a specific pressure on the connected brake pads.
In such circumstances, the brake shoe produces a specific force and pressure to slow down the bus. In addition, it can stop the vehicle at variable stops safely.
The piston pressure and air brakes can slow down the tires gradually and repel vibrations. You can push the pedal and stabilize the bus with gradual braking.
Also, this system has three distinct parts. One is service braking which applies a specific level of pressure.
You can use it by pushing the pedal and opening the connected valve. In such circumstances, the tank pushes the air and flows through the flow passages to the chamber of the braking system.
Reduced air pressure inside the chamber can trigger the emergency brake and reduces the chances of accidents. Pressure lower than 60 PSI (pounds per square inch) is dangerous and activates this emergency braking mechanism.
The parking brakes push the compressed air into the chamber. Then, it applies pressure on the spring, which expands.
It puts additional force on the pushrod and moves it outward. It can activate the camshaft and force the airflow lines to apply brakes.
These properties make the braking beneficial for the buses.
The air brake system uses compressed and pressurized air for its optimized efficiency. Furthermore, the air never removes from it.
Therefore, the compressed air flow remains constant and improves its efficiency. Compressed air cannot cause corrosion and repel the damage to the metallic parts.
The air passages can disengage and engage according to the standard compression ratio. The air does not enter the circuit, which comprises the emergency brake.
However, the failure of the service brakes activates the emergency stop mechanism. Continuous airflow improves the efficiency of the braking system in buses.
No leakage-related failure
Air brakes do not fail because of their performance and layout. They do not have brake fluid which reduces the probability of leakage.
Compressed air cannot leak, which keeps it stable for several years. It has no leakage problems because the air does not leak.
However, low air pressure can affect their performance. The front or rear braking mechanism malfunctions, and you cannot stop the bus.
Reduced failures indicate their stabilized efficiency and optimized performance.
How do air brakes work on buses?
The air brakes work on school buses by using compressed air. They do not require hydraulic fluid for their proper performance.
In addition, they are discs and drums, and you can identify both in one system. The engine compressor develops the pressurized air and pushes it into the storage container.
Then, the stored and pressurized air delivers pressure for the service braking system and removes the force from the parking stop system.
Several circuits work, and the parking braking mechanism pushes the spring and delivers the pressure to the chamber.
In such circumstances, you can use the parking and emergency braking system. The stable air flow can stabilize the braking system, and you can stop the bus at different accelerations.
The compressed air can apply the specie force for pedals and other connected parts.
What is the air brake pressure on buses?
The buses have air-regulated braking mechanisms. However, it has a standard internal pressure for optimized efficiency.
The average pressure of this system is about 80 to 120 pounds per square inch (PSI). The pressure level reduces from the standard range.
Moreover, it reaches 60 PSI (pounds per square inch). It is the lowest pressure which affects the performance of the stop system.
You can check their pressure by using a gauge. The maximum stable pressure varies from 110 to 130 PSI (pounds per square inch).
The compressed air system is stable and efficient. Therefore, the buses with this system can develop a pressure of 85 to 100 PSI (pounds per square inch) without 30 to 40 seconds.
Sometimes, the system takes less time to develop this stable pressure and optimized functionality.
How long do air brakes last on buses?
These vehicles have stable and efficient air brake systems. However, this braking system in buses has a longer lifespan than the hydraulic system.
It does not undergo damage because the system lacks hydraulic fluid. The internal force or compressed air never removes from the system, which increases its lifespan.
However, their average lifespan is about 35000 to 75000 miles without damage to flow lines. It can increase or reduce according to its surface condition, mechanism, internal force, and efficiency.
Their rotors have an extended life expectancy of about 1020000 miles. The range varies according to their use and efficiency.
Maintenance and cleaning can increase their lifespans from the standard level. Their chambers can last for around 130000 miles, which reach 150000 miles according to cleaning, service, proper use, and maintenance.
Also, their filled chambers can repel damage and last several years without significant damage.
Is it dangerous to drive buses with failed air brakes?
Driving a bus with malfunctioning air brakes is dangerous because it leads to sudden rolling and crashes. They malfunction and lose their standard alignment.
Furthermore, they lose from their connecting points, and you cannot install them properly. Reduced maintenance and excessive load can cause their failure.
They malfunction when external pressure can damage them. Internal blockage can decrease the airflow and leads to their malfunctioning.
They undergo locking, and you cannot drive the buses. The compressor malfunctions and affects its performance.
Also, air flow lines damage and lead to leaking. The pressure reduces, and the container cannot compress the air, which leads to reduced control and crashes.