What will occur if the service line ruptures?
If the service line is ruptured or disconnected, no action will take place until a brake application is made. Rupture of the service line will result in the escape of air pressure, if the brake application is held long enough to cause enough loss of pressure in the tractor system.
What is the service line on a truck?
The service line (also called the “control line” or “signal line”) carries air controlled by the foot brake or the trailer hand brake. Depending on how hard you press the foot brake or hand valve, the pressure in the service line will similarly change. The service line is connected to relay valves.
How does a spring brake valve work?
A spring brake control valve is normally a push/pull type valve fitted with a yellow, four-sided knob located near the driver (See diagram 4-3). Most spring brake control valves are pushed to supply air and release the spring brakes, then pulled to exhaust air and apply the spring brakes.
What color is the service line on a tractor trailer?
blue
In most cases, the trailer couplers are colour-coded during manufacturing – red for the supply line and blue for the service line (See Diagram 5-2). By matching these colours, the lines are properly connected.
What is the final factor that will determine if the vehicle will stop?
traction
The final factor that stops a vehicle is not the brakes, but the traction between tires and road surface.
Is red or blue supply?
The red is trailer air supply. This releases the trailer’s parking brake. The blue line is the service brake line. This allows the trailer brakes to be applied when driving.
What is the service line for?
: a line marked on a court in various games (such as handball or tennis) parallel to the front wall or to the net to mark a boundary of the service area or service court.