When you are uncoupling a loaded trailer you should lower the landing gear until?
STEP 4: Lower the Landing Gear If the trailer is empty, lower the landing gear until it makes firm contact with the ground; if the trailer is loaded, turn the crank in low gear a few more turns after the landing gear makes firm contact with the ground.
Where should the tractor be when inspecting the landing gear?
To inspect the landing gear, close the tractor protection valve. Position the tractor: With the tractor frame under the trailer.
When uncoupling the rear semi trailer you should lower the landing gear of the second rear semitrailer?
Lower the landing gear of the second semitrailer enough to take some of the trailer’s weight off the converter dolly, and lower the landing gear of the first semitrailer enough to take some of the trailer’s weight off the converter dolly.
When checking that the trailer is securely coupled to the tractor the landing gear should be?
The landing gear should be slightly raised while you check if the rear trailer is securely coupled to the front tractor. After you’ve backed under the trailer and locked the kingpin into the fifth wheel, raise the landing gear slightly.
When should you lower the landing gear on a loaded trailer?
Use two hands and square feet up to operate the landing gear, and make sure it’s in the proper gear when lowering and raising it. When the trailer is loaded, the landing gear should be in low gear.
How many seconds does it take for a normal tractor trailer to clear a double track?
Do not shift gears while crossing railroad tracks; it takes at least 14 seconds for a typical tractor-trailer unit to clear a single track and more than 15 seconds to clear a double track.
What part of the kingpin should the locking jaws?
When backing under the semi trailer, where should you line up? Directly in front of the trailer. How should you test the tractor semi trailer connection for security?
What will happen if the service air line between the tractor and the trailer comes apart?
If your emergency air line breaks or separates while you’re driving, the emergency trailer brakes will activate, and you’ll need to supply air to the trailer system before pulling the air supply knob.
Why should you lock the tractor glad hands to each other when you are not towing a trailer?
When you’re not towing a trailer, why should you lock the tractor glad hands (or dummy couplers) to each other? A The connected brake circuit acts as a backup air tank. B If you didn’t, you’d never be able to build system pressure.
What 3 methods can you use to secure a second trailer before coupling?
1) Connect the emergency line, charge the trailer air tank, and disconnect the emergency line. 2) Spring brakes. 3) Wheel chocks are the three options for securing a second trailer before coupling.
When you get ready to back under the semi trailer you should line up?
4. When you’re ready to back under the semi trailer, line up as follows: A About 12 degrees off the trailer’s line.
What should the trailer height be before you connect a converter dolly to a second or third trailer?
The trailer height should be slightly lower than the center of the fifth wheel when connecting a converter dolly to a second or third trailer.
What might happen if the trailer is too high?
In addition to improper coupling, backing into a trailer that is too high off the ground can cause damage because the rear of your truck cab may collide with the front of the trailer, and the trailer king pin may become stuck in front of the fifth wheel plate, which can be a costly and time-consuming mistake.
What will happen if the lines are crossed when you hook up to an old trailer?
When hooking up to an old trailer, the driver crosses the air lines. A If the trailer does not have spring brakes, you can drive away, but you will not have trailer brakes. B The brake pedal will operate the trailer spring brakes rather than the air brakes.
Where should the tractor be when inspecting the landing gear after uncoupling the trailer?
After you’ve uncoupled the trailer and 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 to inspect the landing gear.