CDL Air Brakes study plan

Label each major air brake component (compressor, governor, reservoir, drain valve, safety valve, foot valve, brake chamber, slack adjuster, S-cam, wedge, drum, rotor) on a blank diagram you draw from memory

Describe in writing the path of air from compressor to brake chamber during a brake application and during release

State the governor cut-in and cut-out pressure ranges and explain what each signals

Explain the function of the alcohol evaporator or air dryer and the supply/reservoir pressure relationship

Define the roles of the one-way check valve, the low-pressure warning device, and the stoplight switch in your own words

Compare a dual (split) air brake system to a single-circuit system by listing at least four differences

Trace both halves of a dual system and identify which components are protected by each reservoir

Explain the purpose of the safety valve, the spring brake, and the parking/emergency circuit in a dual system

Describe what happens to braking ability when one circuit of a dual system fails

Recite from memory the required warning devices and their pressure thresholds

Order the steps of the pre-trip air brake inspection into a correct numbered sequence without notes

List the specific things checked at each wheel position and at each reservoir drain

Explain the static leak test and the applied (service) leak test, including acceptable pressure-loss limits

Describe the tractor protection valve and trailer air supply checks for a combination vehicle

Identify the three types of slack adjusters and explain how to check pushrod travel

Perform and narrate a full pre-trip air brake inspection in the correct order in under 15 minutes

Diagnose three given inspection scenarios (e.g., slow build-up, excessive pushrod travel, air leak) and state the correct response

Explain when an in-service check is warranted and what to look for while driving

Re-verify dual-system warning device behavior and low-pressure warning activation points

Correct any inspection steps you missed in weeks 1-3 by rewriting those sections of your checklist

Explain the correct technique for normal braking, including how much pressure to apply and when to release

Describe proper downshifting and brake use on long downgrades, including the role of engine braking

Distinguish controlled braking from stab braking and state when each is appropriate

Explain how brake fade occurs and how to prevent it during normal driving

Describe proper braking technique on slippery surfaces, including light pedal pressure and release before lockup

List every low-air-pressure warning signal and state the pressure at which each should activate

Describe the correct response to a low-air warning while driving and the safe stopping procedure

Explain what to do if the spring brakes apply suddenly or if a brake chamber fails

Describe emergency stopping using the parking brake and how to avoid skids and jackknifing

Explain who to notify and what to record after any brake failure event

Explain how and when to use the parking brake, including the proper test that it holds the vehicle

Describe the correct procedure for parking on a grade, including wheel chocking and turning the wheels

Explain how to safely cross water and what to do if brakes get wet

Describe how to dry out wet brakes after crossing water

Explain adjustments to braking and following distance in rain, snow, ice, and fog

Take two full-length practice tests and score both at 90% or above

Review every missed question and re-teach the underlying rule for each

Recite the pre-trip inspection sequence, pressure thresholds, and braking technique from memory

Re-verify all six domains against your notes and close any remaining gaps

Simulate exam-day pacing with one timed practice test and no notes