ND CDL Air Brakes study plan

Label the major components of a truck air brake system (compressor, governor, reservoirs, foot valve, relay valve, slack adjusters, chambers, spring brakes) on a blank diagram from memory

Trace the path of compressed air from the compressor to a front wheel chamber and narrate each component's role aloud in under two minutes

Explain the governor's cut-in and cut-out pressures and why the compressor must unload rather than keep pumping

Distinguish service brakes, parking brakes, and emergency braking functions and name which components serve each

Describe how a dual-circuit system splits front and rear service circuits and what a failure in one circuit leaves the driver

Explain the role of relay valves, quick-release valves, and spring brake chambers in release timing and hold strength

Calculate the spring brake pushrod stroke effect of a misadjusted slack adjuster well enough to explain why adjustment matters to stopping distance

Define key pressures: governor cut-in/cut-out, low pressure warning threshold, and typical reservoir operating range

Perform and document the static leak test sequence: build pressure, shut off engine, watch gauge drop limits for a single vehicle and for a combination

Conduct the applied-leak test by holding the brake pedal and confirming pressure loss stays within limits

Test the low pressure warning device by bleeding pressure down and confirming the warning activates before the minimum threshold

Check the spring brake (parking brake) by confirming it holds the vehicle on a grade and releases fully when pressure builds

Run the full pre-trip air brake inspection in correct order without referencing notes

Identify three common inspection failures (slow build, excessive leak, delayed warning) and state the correct response to each

Explain how to check slack adjuster pushrod travel and what a reading outside the limit means for roadworthiness

Describe the safe procedure for draining reservoirs and why moisture and oil contamination matter

Explain proper brake application technique including controlled, progressive pressure rather than fanning or pumping

Describe how to use engine braking and gearing to control speed on long downgrades without overheating brakes

State the safe following distance and stopping-distance logic for a loaded air-braked vehicle at highway speed

Identify when to test brakes after driving through water and how to dry them out

Explain what causes brake fade and how to recognize the first signs before stopping power is lost

Describe the correct response to a low air pressure warning while driving, including gear selection and safe stopping

Explain what happens when a service circuit fails and how to bring the vehicle to a controlled stop

State the procedure when spring brakes apply automatically due to pressure loss

Describe the response to a brake chamber or line failure including loss of air and use of the remaining circuit

Explain how to use the parking brake and engine braking to stop if service brakes are lost entirely

State the steps for an emergency stop on a downgrade and how to choose an escape route

List post-incident actions after any brake malfunction, including inspection and reporting

Complete a full-length practice test across all four domains and score 90 percent or better

Re-teach the two weakest domains from memory in a five-minute spoken summary each

Re-run the pre-trip inspection and all leak and warning tests cold, with no notes

Review every missed practice question and write the correct reasoning for each