The trailer control valve in the towing vehicle causes the brake system of a trailer to be supplied with compressed air. It also controls the trailer brake system via the service brake system of the towing vehicle and via the parking and auxiliary brake valve.
In the driving position, compressed air flows from the towing vehicle to the trailer and supplies the trailer control valve with supply air. At the same time, there is pressure from the parking brake, which releases the trailer brake.
During emergency braking, the maximum brake pressure enters the trailer brake valve. When the foot brake is released, the brake circuits of the towing vehicle are vented. Subsequently, venting takes place via the trailer control valve of the trailer.
When the parking brake is applied, the trailer control valve bleeds the parking connection. This creates pressure in the brake line to the trailer, causing it to move into brake position.
Note: Accessories are listed on the respective article detail page in the Partner Portal.
Hints & tips:
When replacing the trailer control valve, make sure that the brake system is not under pressure. It is also important that the valve is installed with the vent facing downwards. It is then advisable to check the system for function and tightness.
