WABCO 9730090010 relay valve for SINOTRUK heavy truck

Description

Description of the Heavy Truck Relay Valve WABCO 9730090010： 

The Trailer Control Valve Relay Valve WABCO 9730090010 is a crucial component in the pneumatic braking system of heavy-duty trucks. It is mainly used to accelerate the response speed of the braking system and amplify the braking air pressure, ensuring that the braking effect of vehicles (especially those with long wheelbases or multiple axles) is more rapid and reliable.

When the brake pedal is depressed, the output air pressure of the brake valve acts as the input air pressure for the relay valve. Under the influence of the control pressure, the intake valve is pushed open, so the compressed air directly enters the brake chamber through the intake port instead of passing through the brake valve. This significantly shortens the inflation pipeline of the brake chamber and accelerates the inflation process of the chamber. When the brake pedal is released, the relay valve can quickly discharge the air pressure in the brake chamber, allowing the braking system to quickly return to its initial state and achieve rapid release of braking.

The function of the Relay Valve WABCO 9730090010：

1. Accelerate braking response: Due to the large size and heavy weight of heavy-duty trucks, and the long air path, if the braking air chamber is directly controlled by the foot valve (brake main valve), the braking delay will be very obvious. The Relay Valve WABCO 9730090010 is installed near the braking air chamber, which significantly shortens the inflation pipeline of the braking air chamber and accelerates the inflation process of the air chamber, allowing the braking system to respond to the driver’s operation instructions more quickly and effectively reducing the braking response time.
2. Prevent overload of the braking system: By using the relay valve, it can prevent the driving and parking systems from operating simultaneously, avoiding the force overlap in the combined spring brake cylinder and spring brake chamber, thereby preventing the mechanical transmission components from operating under excessive load.
3. Improve the reliability and stability of braking: At the end of the long pipeline, such as in the braking system of trailers or semi-trailers, the relay valve enables the spring brake cylinder to quickly charge and exhaust, ensuring that the braking system responds promptly and works effectively, thereby enhancing the reliability and stability of braking.

The structure of the Relay Valve WABCO 9730090010:

• Control port (12 ports): Receives the control air pressure signal from the brake main valve.
• Inlet port (1 port): Connects to the air reservoir to provide a high-pressure air source.
• Outlet port (2 ports): Connects to the brake chamber to output the braking air pressure.
• Exhaust port (3 ports): When braking is released, quickly expels the gas from the brake chamber.
• Diaphragm, piston, spring: Used to sense the control air pressure and regulate the output air pressure.

Relay Valve WABCO 9730090010 Common Faults and Solutions:

1. Exhaust Port Leakage: This may be due to the improper closure of the bypass valve or the exhaust valve, which is often caused by damaged sealing elements or the presence of impurities or foreign substances. You can test by applying soap water at the exhaust port of the relay valve and checking for bubbles. If bubbles appear, disassemble the exhaust pipe of the relay valve and observe if there is any gas coming out from the exhaust port. If there is gas, then the relay valve needs to be replaced.
2. Slow Release of Braking: Remove the air pipe at the exhaust port of the relay valve, connect the pressure gauge to the exhaust port of the relay valve, press the brake pedal to the floor and quickly release it. Observe the reading on the pressure gauge. If the reading does not drop to zero quickly, then the relay valve needs to be replaced.
3. Frozen Relay Valve: This is mainly caused by the short spiral heat dissipation tube, reduced filtering performance of the drying tube, or failure to drain water from the air reservoir regularly, resulting in water accumulation and ice formation inside the valve. To prevent and solve this issue, you can replace the appropriate length of the spiral heat dissipation tube, replace the drying tube, or regularly drain water from the air reservoir.

Relay Valve VS four circuit protection valve Comparison:

Relay Valve WABCO 9730090010 is a key component for enhancing the braking response speed of heavy-duty trucks, especially for vehicles with long wheelbases and multiple axles. Its main function is to reduce braking delay and can amplify the braking force as needed. It is essential to regularly check the sealing performance of the relay valve and ensure smooth exhaust. This can prevent braking failure or drag-braking problems. During maintenance, it is necessary to distinguish the functions of the relay valve and the four-loop protection valve to avoid confusion. If you need more specific models or maintenance instructions of WABCO 9730090010, please contact ZK truck spare parts. We will provide free installation services.