If you find a problem with the brake system when the tractor is connected to the semi-trailer, you can follow the steps below to troubleshoot and solve it:
1. Check the air connection
- Check whether the air connection is firm: Make sure that the air connection between the tractor and the semi-trailer is correct and there is no air leakage. After the air connection, you need to unscrew the semi-trailer air connection separation switch on the tractor to put it in a ventilated state.
- Check whether the air pressure is normal: Start the engine, increase the pressure in the tractor and semi-trailer air tanks to the specified pressure (generally 650-750kPa), and check whether there is any air leakage in the air circuit.
- Check the leakage point: If it is found that the air pressure is lower than 0.7MPa for a long time or the trailer brakes during driving, you can check the leakage source by applying soapy water to eliminate the following possible fault points:
- Leakage at the handshake connection
- Leakage at the pipe joint
- Air cross-talk in the brake air chamber
- Leakage in the emergency relay valve
- Leakage in the trailer ABS valve
2. Check the brake system components
- Check the brake air chamber: If the air leakage still exists, check whether the valve body has water ingress or obvious rust. If there is a problem with the valve body, the valve body may need to be replaced.
- Check the emergency relay valve: The emergency relay valve is an important component of the trailer's brake system. If it fails, it may cause insensitive braking or dragging.
- Check the ABS system: If you suspect that there is a problem with the ABS system, you can unplug the ABS spiral wire to see if it can start normally to eliminate circuit problems.
3. Check the parking brake
- Check whether the parking brake is released: If the trailer cannot be started after parking, it may be that the parking brake is not released. Check whether the parking brake is in the released state.
- Check the manual valve air pressure: Put the tractor in the inflated state, unplug the air pipe of the manual valve, and check whether the air pressure at the outlet is normal (the air pressure should be very high in the inflated state).
4. Check mechanical failure
- Check axles and brakes: If there is no problem with the air circuit inspection, the mechanical failure of the axles and brakes should be checked eventually.
5. Other precautions
- Avoid self-modification: More and more customers modify the trailer air circuit by themselves. Due to improper modification, the original brake system may be damaged, resulting in safety and quality accidents. It is recommended to complete the vehicle modification in a regular modification unit or the original factory.
- Regular maintenance: Regularly check and maintain the brake system to ensure that all components are in good condition and avoid safety accidents caused by brake system failures.
Through the above steps, you can effectively troubleshoot and solve the problems of the brake system when the tractor is connected to the semi-trailer to ensure driving safety.