California CDL Air Brakes Test study guide
California CDL Air Brakes Test · Work through your exam, one topic at a time.
The California CDL Air Brakes Test is a knowledge exam that commercial drivers must pass to operate vehicles equipped with air brakes. It applies to drivers pursuing a Class A or Class B commercial license, and to drivers who already hold a CDL but need the air brake endorsement or want the air brake restriction removed from their license. The California CDL Air Brakes Test study guide has 6 sections and about 2,271 words.
01Air Brake System Components and Functions
Learn the system as a chain of pressure: compressor, governor, reservoirs, foot valve, brake chambers, slack adjusters, foundation brakes. The compressor (engine-driven, belt or gear) builds pressure and is protected by an air dryer that removes moisture and oil before air reaches the tanks.
380 words, about 2 min02Dual Air Brake System and Air Supply
A dual (split) system divides braking into two independent circuits so a single leak cannot take out all braking. Each circuit has its own reservoir, check valve, and low-pressure warning; typically one circuit serves the front axle and the other the rear axle(s), and the parking/emergency circuit is charged separately.
366 words, about 2 min03Inspecting the Air Brake System (Pre-Trip Checks)
Use the same order every time so nothing is skipped. Start with the engine off and chock the wheels.
380 words, about 2 min04Normal Operating Procedures and Braking Technique
Air brakes are not instantaneous like hydraulic brakes - there is a lag while pressure travels to the chambers. Apply the pedal firmly and hold it ; fanning or pumping the pedal wastes air and can leave you with less reserve when you need it.
357 words, about 2 min05Air Brake System Failures and Emergencies
Failures show up as sound, feel, or gauge movement. Audible leaks (hiss at a chamber, hose, or valve), a gauge that keeps dropping , a low-pressure warning , a spring brake that applies by itself , or a pedal that feels spongy or goes to the floor all demand action.
398 words, about 2 min06Parking Brakes, Retarders, and Anti-Lock Brake Systems
The parking brake on an air-brake vehicle is the spring brake : a heavy spring applies it and air pressure releases it. Pushing the dash knob in charges the chambers and releases the brake; pulling it out exhausts air and applies the brake.
390 words, about 2 min