NC CDL Air Brakes study plan
NC CDL Air Brakes · Give each week a clear focus.
8 weeks · About 6 hours per week
Air Brake System Components and Warning Devices & Air Brake Inspection and Pre-Trip Checks
Diagram the air brake system from memory: compressor, governor, reservoirs, safety valve, foot valve, brake chambers, slack adjusters, and the lines that connect them
State the cut-out and cut-in pressures of a typical governor and explain what happens to compressor output at each threshold
Identify every dash warning device on an air brake vehicle and the exact condition that triggers each one (low air pressure buzzer/light, ABS lamp)
Recite the pressure-loss limits used in the static leak test and explain why each threshold exists
Your checkpoint
A hand-drawn system diagram with every component labeled, plus a one-page table mapping each warning device to its trigger condition and required driver response
Air Brake Inspection and Pre-Trip Checks & Air Brake System Components and Warning Devices
Perform the full pre-trip air brake sequence in correct order: drain tanks, build pressure, static leak test, applied leak test, low-pressure warning test, and compressor recovery check
Explain the purpose of draining air tanks and describe what comes out of each tank and why
Calculate acceptable pressure loss for a given tank size and time interval instead of memorizing one number
Describe the slack adjuster and pushrod stroke check and identify when a stroke is out of adjustment
Your checkpoint
A written pre-trip checklist in your own words, in correct sequence, with the pass/fail criterion for each step and a worked pressure-loss calculation
Air Brake Operation and Braking Technique & Air Brake Inspection and Pre-Trip Checks
Explain the correct braking technique for a downgrade, including gear selection before the descent and the reason for braking below the safe speed
Describe how to use the trailer hand valve correctly and state the one situation where it must never be used
Explain the interaction between engine retarder, service brakes, and hot brake fade on a long grade
Demonstrate the correct sequence for a brake test at the start of a trip and state how long a full pressure build should take
Your checkpoint
A written downgrade plan for a hypothetical 6 percent grade of known length: gear at the top, target speed, brake application strategy, and the action taken if speed climbs anyway
Air Brake Malfunctions and Emergency Procedures & Air Brake System Components and Warning Devices
List the causes of slow pressure buildup and explain how to distinguish a compressor problem from a leak
Describe the spring brake parking system, including how air releases the spring and what happens when pressure is lost
Explain the correct procedure for freeing a vehicle with frozen or stuck spring brakes without damaging the system
State the action sequence when the low-pressure warning activates while driving
Your checkpoint
A troubleshooting table with at least six symptoms (slow buildup, pressure drop while driving, one brake dragging, spring brakes will not release, warning buzzer stays on, rapid loss after shutdown), each with likely causes and the safe driver action
Milestones
Week 4: Score at least 85 percent on a 25-question self-made quiz covering Domains 1 and 2, and perform the pre-trip air brake sequence out loud from memory with no missed step