Answer :
Final answer:
Do not move the tractor after pushing in the trailer supply valve until the air system has reached the correct pressure, as indicated by the pressure gauge, to ensure the air brakes work properly.
Explanation:
When you have pushed in the trailer supply valve on a tractor-trailer vehicle, it is important not to move the tractor until the whole air system is at the correct pressure. Air brakes require sufficient pressure in order to function properly.
You should wait for the air pressure to build up to the manufacturer's specified level, which is usually indicated by a pressure gauge on the dashboard. Driving with an air system that isn't fully pressurized can lead to brake failure and is extremely dangerous.
Before moving the tractor, it is important to ensure that the entire air system is pressurized. This means that the air tanks in both the tractor and the trailer should be fully filled with compressed air. Moving the tractor without a properly pressurized air system can compromise the effectiveness of the brakes on the trailer.
Therefore, it is crucial to wait until the air pressure gauge in the tractor shows that the air system is fully pressurized before moving the vehicle.
