What does the trailer supply valve do?
The PP-7™ trailer supply valve provides in cab control for the tractor protection system and functions in conjunction with the park control valve. It is responsible for synchronizing the tractor and trailer parking and emergency brakes.
What color is the trailer parking brake?
The green wire is the right turn/brake, the yellow wire is the left turn/brake, the white wire is the ground, and the brown wire is the electric wire. It is best to wire by function as wire colors can vary.
How can a driver control the trailer brakes independently?
How can a driver control the trailer brakes independently? The purpose of the trailer brake hand valve (30) is to allow the driver to control independently the amount of application air pressure to be directed to the trailer brakes.
What makes a tractor trailer Come unhooked from the 5th Wheel?
Finally, by checking the 5th wheel connection visually in combination with a tug test, you can be sure that the only way the trailer will inadvertently come unhooked is through mechanical failure
How long does it take to hook up a trailer to a tractor?
Hooking a trailer to a tractor is simple after some repetition, and if done in the above order with the proper checks. If the order is changed or the checks are not conducted, a trailer will likely end up on the ground at some point during your career. In the “real world of trucking” this procedure should take less than 5 minutes.
How do you hook up a tractor to a dolly?
Place the dolly so its fifth wheel touches the front of Trailer 2 and its fifth wheel jaws are in line with Trailer 2’s king pin. Back the tractor-semitrailer combination into position in front of the dolly.
How do you hook up a 5th wheel to a trailer?
a. Handle is in (position when 5th wheel jaws are in the locked position) b. There is no “day” light or space between the 5th wheel and the trailer c. The 5th wheel jaws are locked behind the trailer king pin (use a flashlight) 5. Wind up the trailer landing gear an inch 6. Conduct a tug test to confirm that the 5th wheel is locked to the king pin