What should I do if the relay valve is frozen? Winter braking system pay attention to these

In the cold winter season, some cardholders' trailers will have some problems due to the decrease in temperature, such as the relay valve being frozen, resulting in brake locking, and the potential safety hazards are great.

Today, I will share with you how to deal with the problem of the relay valve being frozen and how to maintain the trailer brake system in winter.

▎The working principle of the relay valve

The relay valve is an integral part of the braking system, and at the same time plays a role in the braking system to shorten the reaction time and pressure establishment time, the truck relay valve inlet is connected to the air reservoir, and the air outlet is connected to the brake chamber.

When the truck is driving, the brake pedal is pressed, and the output air pressure of the relay valve is used as the control pressure input, and under the action of this pressure, the intake valve is pushed open, and the compressed air enters the brake chamber directly from the air reservoir without passing through the relay valve. The inflation line of the brake chamber is shortened and the inflation process of the chamber is accelerated.

▎Why is the relay valve frozen?

Under normal circumstances, there are three reasons why relay valves are frozen:

1. The spiral heat pipe is too short, and the water will be excluded when the air is compressed at high temperature and cold, and water will accumulate in the valve body, and it will freeze when the water is lower than 0 degrees, and the valve chamber may be stuck.

2. The filtration performance of the drying pipe is reduced, and the water vapor in the air is not filtered cleanly, resulting in water accumulation in the pipeline and valve body, which affects the normal use of the brake.

3. The air reservoir does not release water regularly, resulting in water accumulation inside the air reservoir entering the valve body, and when the temperature is too low, it will lead to freezing and other conditions.

▎What should I do if the relay valve is frozen?

When the relay valve is frozen, many cardholders may use fire roasting, pouring boiling water, adding alcohol to the gas reservoir, etc., but these methods can only save the emergency and are not suitable for long-term use. If you want to solve the problem fundamentally, you can try the following methods:

1. Before cooling, the maintenance of the valve body should be done, and a small amount of petroleum jelly should be applied inside the valve body to help the lubrication of the piston in the valve body.

2. Regularly check whether there is stagnant water in the gas reservoir, so that it is discharged regularly, and if there is too much stagnant water, the replacement of the drying tank should be considered.

3. Check whether the compressed air in the air reservoir can be well dissipated, if the compressed air is too hot, the length of the spiral tube should be extended to solve it.

Especially in the north of the driving card friends in the encounter with maintenance because of the weather will be very uncomfortable, relay valve as an important part of vehicle braking, usually must do a good job of inspection, to avoid driving failure.

In addition, it is very important to maintain the trailer brake system, and in winter driving, the following aspects should be prepared:

1. Check the gas joints (including the connection between the main vehicle and the trailer)

With the advent of winter, the lower the temperature, the harder the sealing ring or mat, after the wind and rain in summer, the sealing of the rubber ring is getting worse and worse, especially the pipeline joint above the axle, the low temperature in winter will cause the sealing pipe joint to shrink, and the sealing performance is poor and leaking, so we must check the sealing of each joint of the gas circuit before leaving the car in the morning. (It is best to be able to shake it with your own hands and touch it) if there is an air leak, tighten it in time or reinstall it.

2. Check the main car drying tank

Check the dryer tank of the main car to ensure that the air source of the main car is dry and free of moisture. Since the drying tank is an air filter, it loses its filtering effect on the residual water vapor of the compressed air with the length of use. The compressed air does not achieve the purpose of drying, resulting in water accumulation and freezing in the pipeline and valve body, which affects the normal use of the brake.

3. The main car and trailer are regularly drained of stagnant water

In winter, the temperature in the north is mostly below zero, at this time, the compressed gas is easy to produce water droplets or moist gas, the main car and trailer gas reservoir regularly release water, and the regular release of water in winter is shorter than the summer interval, requiring frequent water release to ensure that the dry gas used by the brake. If the water is not discharged in time, the pressure of damp gas inside the air reservoir will enter the valve body, and when the temperature is lower than zero, the inside of the valve body will be frozen. As a result, the piston in the valve body is stuck, and the brake failure occurs.

4.ABS system maintenance

ABS is connected to a plurality of sensor connectors, which is used to sense signals for the braking system, so that ABS will give certain instructions at a specific speed of the vehicle to exert the best braking force and frequency. Therefore, whether the sensor joints are loose or not, to ensure that they are fixed, needs to be checked and maintained.

At the same time, the ABS gear ring in the brake drum should be removed and cleaned regularly to ensure that the sensing signal between the gear ring and the probe is good, and the joint is free of putty.

When the temperature drops, the car and people will have some discomfort, so we should pay more attention to the inspection of the inspection, the maintenance of the maintenance, do not relax.