The DMV doubles triples practice test will examine your knowledge of pulling double/triple trailers, coupling and uncoupling, inspecting doubles and triples, and checking air brakes. In order to receive your Doubles and Triples endorsement, it is required that you pass the state’s official CDL written Knowledge exam.

Doubles & Triples Endorsement Test 02

1 / 30

When checking the fifth wheel, you should make sure that it has enough...?

2 / 30

In the coupling system, the locking jaws should be fixed around...?

3 / 30

To check that the trailer emergency brakes are working properly, you should pull out the trailer air supply control and...?

4 / 30

When checking your air lines, they must be secure and...?

5 / 30

Light cords should be attached to...?

6 / 30

If your tractor protection valve doesn't work properly, then if an air hose starts to leak what could happen?

7 / 30

If the fifth wheel on a coupling is too far forward, the tractor frame may hit...?

8 / 30

In normal operation, trailer service brakes should be operated by...?

9 / 30

If the converter dolly is close to your semitrailer, you should wheel it into position...?

10 / 30

How many different ways of coupling and uncoupling trailer combinations are there?

11 / 30

For all brakes to work on a triple combination, you must have air supply...?

12 / 30

Once you have coupled your rear trailer, you should test the coupling by...?

13 / 30

When uncoupling a rear trailer, you should remove some weight from the dolly by...?

14 / 30

A dolly should be pulled out from a rear trailer using...?

15 / 30

In this order, the shutoff valves at the rear of front trailers, the rear of the last trailer and the converter dolly air tank drain valve should be...?

16 / 30

On double and triple combinations, you must make sure that which of these is secure?

17 / 30

The coupling between a rear trailer and a dolly should have a space between the upper and lower fifth wheels of...?

18 / 30

You can test that air is flowing to all trailers by opening...?

19 / 30

When connecting a converter dolly to a rear trailer, the trailer height must be adjusted so that it is...?

20 / 30

If your converter dolly has to be moved over a distance to bring it to your semitrailer, you should...?

21 / 30

The final procedure when connecting a rear trailer is to...?

22 / 30

A bent or damaged kingpin on a coupling should be...?

23 / 30

To check air flows to all trailers, you should let air pressure reach normal then...?

24 / 30

Converter dollies are connected to front trailers with a...?

25 / 30

When testing trailer service brakes, you should use...?

26 / 30

On a triple combination, the shutoff valves on the rear of the last trailer should be...?

27 / 30

When uncoupling a rear trailer, your rig should be parked in a straight line on...?

28 / 30

Your tractor protection valve control should pop out, or go from normal to emergency position, when air pressure falls into what range?

29 / 30

On a triple combination, the shutoff valves at the rear off the middle trailer should be...?

30 / 30

Before coupling a trailer, you should make sure it is at the right height using...?

Your score is


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