Double

This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test The test consists of 15 multiple choice.. Read More

This endorsement is required if the driver will pull two or three trailers. To receive this endorsement, applicants must pass a test The test consists of 15 multiple choice questions. Each question has three answer choices. To pass, the applicant must answer at least 12 questions correctly. Test questions come from the California Commercial Driver Handbook. Questions come from chapters covering: Driving Safely, Air Brakes (if applicable), Combination Vehicles and Doubles and Triples. The Double/Triple endorsement can be used with the Class A CDL.

Number of Question
Passing Score

1. In a dual air brake system, air pressure should build from 85 to 100 psi within ____ seconds.

Explanation
When inspecting a vehicle with a dual air brake system, you should wait for air pressure to build from 85 to 100 psi in both the primary and secondary systems. This should take about 45 seconds.

2. What happens when a vehicle hydroplanes?

Explanation
On a wet road, it is possible for a vehicle's tires to lose traction with the road surface and begin to glide along on the layer of water. This is referred to as hydroplaning. Hydroplaning can occur at speeds as low as 30 mph.

3. A driver who stops at a green light could be:

Explanation
It is important to observe other drivers' actions and identify clues that a person could be driving impaired. Drivers who have had too much to drink, are sleepy, are on drugs, or are ill can present hazards to other drivers. One sign that a driver may be impaired is that they stop in inappropriate places, such as at green traffic lights.

4. How can you check for a leak in hydraulic brakes?

Explanation
Check hydraulic brakes by pumping the brake pedal three times before applying firm pressure to the pedal for five seconds. The pedal should not move. If it does, there may be a leak or some other problem in the braking system.

5. As part of a pre-trip inspection, you should look for all of the following, except:

Explanation
When inspecting your tires, verify that there is tread depth of at least 4/32 of an inch in every major groove on the front tires and tread depth of at least 2/32 of an inch in grooves on the other tires. Be sure that your tires are not too worn, are not cracked, have proper air pressure, and are all equally sized.
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