In the operation of modern commercial vehicles, the normal operation of the brake air dryer is crucial. Once the dryer fails, the moisture in the compressed air will not be effectively removed, which directly threatens the reliability of the brake valve body. In an environment with a humidity of more than 70%, after the water-containing air enters the brake valve, the corrosion rate of the metal parts will be significantly accelerated, usually reaching 3 to 5 times the corrosion rate. Taking the failure case of a well-known brand of dryer as an example, the inside of the valve body showed obvious corrosion in just six months, causing the valve core to jam and eventually cause brake failure. This rust will not only affect the response speed of the brake system, but may also cause the valve body to completely fail in emergency braking, causing the vehicle to lose its braking ability and bring serious safety hazards.
In addition, the corrosion of the brake pipe system is also a major hidden danger caused by the failure of the dryer. The acidic substances formed by the condensation of water on the inner wall of the pipe will continue to corrode the metal pipe wall, especially in the coastal salt spray environment. The corrosion rate of the pipe caused by the failed dryer can be as much as 4 times faster than the normal working condition. Due to the failure of the dryer, a logistics fleet had perforations in the brake pipe within 18 months, causing brake fluid leakage, which directly caused the vehicle to lose control. This corrosion not only shortens the service life of the pipeline, but also significantly increases the risk of sudden failure, bringing great challenges to corporate operations.
Failure of the dryer may also cause failure of the air system, and this failure is often hidden. When the regeneration system fails, the adsorption capacity of the desiccant decreases, and the moisture in the air will enter the brake air chamber with the compressed air. In a low temperature environment, the moisture condenses into ice, which may cause the air chamber diaphragm to rupture. Due to the failure of the dryer, a transportation company in the northern region frequently suffered air chamber freezing and cracking accidents in winter, and the cost of each repair was as high as 3,000 yuan. This failure not only caused direct economic losses, but also increased vehicle downtime, seriously affecting transportation efficiency.
Failure of the dryer directly led to the deterioration of braking performance. When the air humidity exceeds 50%, the response time of the braking system will be extended by 20% to 30%. In a test on a certain highway, the failed dryer increased the braking distance. When the vehicle was at a speed of 100 kilometers per hour, the braking distance was extended by 6 meters. This performance degradation can be fatal in emergency situations, especially on slippery roads or long downhill sections. A failed dryer may directly lead to serious accidents such as rear-end collisions or rollovers.
Overall, dryer failure poses a systemic challenge to the vehicle maintenance system. Failures caused by failed dryers are characterized by multiple occurrences. Statistics from a heavy truck manufacturer show that after the dryer fails, the maintenance costs related to the brake system increase by 40%. This cost increase includes not only the replacement of parts, but also the loss of vehicle downtime caused by the failure. What's more serious is that a failed dryer may cause a chain failure. For example, after the brake valve fails, the dryer, pipeline and air chamber need to be replaced at the same time, and the maintenance cost increases exponentially.
