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

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

2 / 30

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

3 / 30

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

4 / 30

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

5 / 30

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

6 / 30

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

7 / 30

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

8 / 30

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

9 / 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...?

10 / 30

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

11 / 30

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

12 / 30

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

13 / 30

Light cords should be attached to...?

14 / 30

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

15 / 30

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

16 / 30

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

17 / 30

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

18 / 30

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

19 / 30

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

20 / 30

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

21 / 30

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

22 / 30

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

23 / 30

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

24 / 30

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

25 / 30

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

26 / 30

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

27 / 30

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

28 / 30

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

29 / 30

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

30 / 30

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

Your score is


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