Texas CDL Section 5 Questions and Answers Already Passed

Texas CDL Section 5 Questions and Answers Already Passed Name the 3 different braking systems 1. Service Brake (normal brake pedal) 2. Parking Brake (apply/release with parking brake control) 3. Emergency Brake (uses part of service and parking brake to stop vehicle in brake system failure) What is the air compressor? It pumps air into the air storage tanks reservoirs. Why should you avoid pressing the brake pedal unnecessarily? It can let air out faster than the compressor can replace it. Air pressure can get too low. When does the low air pressure warning signal typically go off? Before the pressure falls below 60 psi What type of brakes must all trucks, truck tractors, and buses be equipped with? Emergency brakes and parking brakes that must be held by mechanical force (usually spring brakes) When do spring brakes typically come on? When air pressure drops to 20-45 psi (usually 20- 30). What is the parking brake knob look like on most new vehicles? Diamond-shaped, yellow, push-pull control knob. Pull-on. Push-release. What should you never do when spring (parking) brake is on? Do not push down the brake pedal. Why must air tanks be drained? To get rid of water and oil that can get in tanks and damage system. What is the supply pressure gauge used for? Tells how much air pressure is in the tanks. All vehicles with air brakes must have a low air pressure warning - True or False? True What are spring brakes? Mechanical force brakes (typically emergency and parking brakes) that can be put on manually or can trigger on when driving if air pressure brakes fail. Front wheel brakes are good under all conditions - True or False? True. If your vehicle has a Front Brake Limiting Valve, what position should the control be in for normal stopping power? Keep in the "normal" not "slippery" position. (Slippery cuts normal pressure to front tires by half) What is a dual air brake system? System that has 2 separate air brake systems that use a single set of brake controls but each system has own tanks, hoses, etc. What are the slack adjusters? Part of S-cam air brake system attached to push rod. How can you check slack adjusters? On manual slack adjusters, turn off parking brake, use gloves and pull hard on each slack adjuster - it should move less than an inch when pulled. How can you test the low pressure warning signal? 1. Shut engine off with enough air pressure that low pressure signal is not on. 2. Turn electrical power on. 3. Step on and off brake pedal to reduce air pressure. 4. Alarm must come on before pressure drops below 60 psi