When towing a trailer the service and supply air line shut off valves should be in what position?
open position
The shut off valves, when in the open position, allows air to flow out to another trailer. If you’re only pulling one trailer, the shut off valves should always be closed or else the air will simply escape out the back of the trailer.
When uncoupling a trailer after you have shut off the trailer air supply and locked the trailer brakes you should?
STEP 2: Ease Pressure on Locking Jaws
- Shut off trailer air supply to lock trailer brakes.
- Ease pressure on fifth wheel locking jaws by backing up gently. (This will help you release the fifth wheel locking lever.)
- Put on parking brakes while tractor is pushing against the kingpin.
What is the red air line on a trailer?
emergency brake
Air and Electrical Lines The red line is the air line for the trailer’s emergency brake. The green line is the electrical line. The blue line is the air line for the trailer’s service brake. Connect these lines to the corresponding couplers and socket on the trailer before moving the trailer.
Where should the tractor be when you inspect the landing gear after uncoupling the trailer?
Where should the tractor be when you inspect the landing gear after uncoupling the trailer? After you’ve unlocked the fifth wheel, pull the tractor forward until the fifth wheel is out from under the trailer but the tractor frame is still under the trailer.
How do you secure a trailer hitch?
Secure the coupler clamp with the hitch pin that came with the hitch. Use safety chains to link the trailer to the tow vehicle; you should cross the chains. You cross the chains to act as a fail-safe to catch the trailer should it somehow become detached. Connect any electrical components if your trailer has them.
What is the Red Line on a trailer?
The red line is the air line for the trailer’s emergency brake. The green line is the electrical line. The blue line is the air line for the trailer’s service brake.
What is the Green Line on a trailer?
The green line is the electrical line. The blue line is the air line for the trailer’s service brake. Connect these lines to the corresponding couplers and socket on the trailer before moving the trailer.
What are the Air Lines for a trailer?
The red line is the air line for the trailer’s emergency brake. The green line is the electrical line. The blue line is the air line for the trailer’s service brake. Connect these lines to the corresponding couplers and socket on the trailer before moving the trailer.
What causes compounding in a trailer service line?
The compounding occurs when service air pressure is trapped in the trailer service line by the tractor protection valve when the supply line is released to atmosphere. Compounding is prevented by connecting the trailer service line to the appropriate port of the trailer spring brake control valve through a tee.