Washington CDL Combination Practice Test (WA) 2

4.9 out of 5 (40 votes)
80% Passing score
20 Questions
4 Mistakes allowed
Preparing for your Commercial Driver's License (CDL) in Washington state? Our Washington combination CDL test offers a thorough and effective way to solidify your understanding of key concepts. Tailored specifically to the unique driving conditions found across the Evergreen State, this WA combination vehicle test challenges you with 20 multiple-choice questions covering essential topics such as inspection procedures, safe driving practices, and air brake systems. With a passing score of 16 out of 20, you'll feel more confident tackling the official state driving test practice. Washington state's diverse terrain-from the misty mountain passes of the Cascades to the rainy streets of Seattle and the open roads of Eastern Washington-demands a high level of skill and knowledge for safe driving. This WA DOL practice test delves into critical areas, like the risks associated with jackknifing. Given Washington state's varied weather conditions, understanding how to handle a trailer in potentially slippery situations is crucial. The CDL combination test emphasizes smooth braking and careful handling, helping you master the art of maintaining alignment between the tractor and trailer, even when roads are wet or icy. While this Washington practice written driving test does not replace a state-certified driver's education or Entry-Level Driver Training (ELDT) course, it serves as an excellent complement. Many of our users find that integrating this knowledge test practice with their formal training boosts their overall understanding and preparedness. Our questions are meticulously crafted and reviewed by professional driving instructors who bring decades of experience in helping drivers earn their licenses. In addition to focusing on national driving standards, our WA combination CDL test is specifically designed with Washington state regulations in mind. This means you're not just learning general concepts; you're studying the rules, regulations, and road signs that apply directly to Washington's roads. Whether you're navigating the busy urban streets of the Puget Sound region or the rural highways in the eastern part of the state, this state driving test practice equips you with the knowledge you need to pass your WA permit practice test with flying colors.
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Sample Washington Combination Test Questions

Question 1

Which procedure correctly tests the trailer emergency brakes?

  1. A Open both air-line shutoff valves at the rear of the last trailer
  2. B Pull out the trailer air supply control, then gently pull against the trailer with the tractor
  3. C Turn off the engine and repeatedly press the brake pedal
  4. D Release every parking brake and move the combination forward

Correct answer: B – Pull out the trailer air supply control, then gently pull against the trailer with the tractor

First charge the trailer air brake system and verify that the trailer rolls freely. Stop, pull out the trailer air supply control or place it in the emergency position, and then pull gently against the trailer with the tractor. Resistance confirms that the trailer emergency brakes have applied.

Source: Washington State Commercial Driver Guide — § 6.5.2, “Combination Vehicle Brake Check”—“Test Trailer Emergency Brakes”

Question 2

What does off-tracking describe in a combination vehicle?

  1. A The driver’s wheels leaving the paved roadway during a turn
  2. B The trailer reversing direction while rounding a curve
  3. C The rear wheels following a different path from the front wheels during a turn
  4. D The vehicle traveling on an unpaved road

Correct answer: C – The rear wheels following a different path from the front wheels during a turn

Off-tracking occurs because the rear wheels follow a different, more inward path than the front wheels while the vehicle turns. The trailer’s rear wheels off-track more than the tractor’s rear wheels, and longer combinations experience a greater effect. The driver must account for this path when turning around curbs, pedestrians, and other obstacles.

Source: Washington State Commercial Driver Guide — § 6.1.6, “Turn Wide”

Question 3

What should a driver know about air-braked trailers and converter dollies built before 1975?

  1. A They may not have spring brakes
  2. B Their greater weight makes them safer to operate
  3. C They normally require a glad-hand converter
  4. D They must have an antilock braking system

Correct answer: A – They may not have spring brakes

Converter dollies and trailers built before 1975 may not have spring brakes. On units without spring brakes, the emergency brakes operate using air stored in the trailer tank and will hold only while adequate pressure remains. These trailers have no parking brake, making wheel chocks essential when they are parked.

Source: Washington State Commercial Driver Guide — § 6.2.8, “Trailer Service, Parking and Emergency Brakes”

Question 4

Which feature indicates that a trailer is equipped with ABS?

  1. A Every trailer automatically has ABS
  2. B The brakes pulse during a high-speed emergency stop
  3. C A yellow ABS malfunction lamp is located on the trailer’s left side, at a front or rear corner
  4. D The trailer uses spring brakes

Correct answer: C – A yellow ABS malfunction lamp is located on the trailer’s left side, at a front or rear corner

A trailer equipped with ABS has a yellow malfunction lamp on its left side, either at the front or rear corner. Washington’s guide notes that identifying ABS on some older trailers may be more difficult. In that situation, the driver can look underneath for an electronic control unit and wheel-speed-sensor wires leading from the brakes.

Source: Washington State Commercial Driver Guide — § 6.3.1, “Trailers Required to Have ABS”

Question 5

During a fifth-wheel inspection, the locking jaws must be closed around which part of the kingpin?

  1. A The head
  2. B The polished upper section
  3. C The shank
  4. D The mounting base

Correct answer: C – The shank

Correct fifth-wheel coupling requires the locking jaws to close around the kingpin’s shank. The driver should inspect the connection from behind the fifth wheel and also verify that there is no gap between the upper and lower fifth wheel. The coupled unit must not be driven if the jaws are incorrectly positioned.

Source: Washington State Commercial Driver Guide — § 6.4.1, “Coupling Tractor-Semitrailers”—Step 13, “Inspect Coupling”

Question 6

Why should unused air lines be placed on dummy couplers or, when compatible, have their glad hands locked together?

  1. A To circulate and clean the air repeatedly
  2. B To convert the disconnected lines into an extra air tank
  3. C To keep water and dirt out of the couplers and air lines
  4. D To increase the tractor’s available braking pressure

Correct answer: C – To keep water and dirt out of the couplers and air lines

Dummy couplers should be used when the air lines are not connected to a trailer. They prevent water and dirt from entering the couplers and lines. If dummy couplers are unavailable, some compatible glad hands can be locked together to protect the openings and help keep the air supply clean.

Source: Washington State Commercial Driver Guide — § 6.2.5, “Hose Couplers (Glad Hands)”

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