CDL Air Brake Practice Test 2024 - 25 Questions with Detailed Explanations

why must air tanks be drained a to check the air pressure B to remove moisture and oil C to refill with fresh air D to test the air compressor answer B to remove moisture and oil compressed air in the system usually contains moisture and oil which can be harmful to the air BR system moisture for example can freeze in cold weather leading to break failure the water and oil accumulate at the bottom of the air tank necessitating the need to drain these tanks completely at the end of each day of driving what is a supply pressure gauge used for a to measure the temperature of the air tank B to indicate the amount of air pressure available to the air brake system C to check the oil level in the air tank D to monitor the speed of the vehicle answer B to indicate the amount of air pressure available to the air brake system vehicles with air brakes are equipped with a pressure gauge connected to the air tank this gauge indicates the amount of pressure in the air tanks in vehicles with a dual air brake system there might be a gauge for each half of the system or a single gauge with two needles all vehicles with air brakes must have a low air pressure warning signal true or false answer a true a low air pressure warning signal is mandatory for vehicles with air brakes this warning often a red light and possibly accompanied by a buzzer activates before the air pressure in the tanks Falls below 60p PSI it alerts the driver to low air pressure which is critical for safe operation what are spring brakes a brakes used in the spring season B brakes that use air pressure to operate C parking or emergency brakes that use spring pressure D brakes that are easier to press answer C parking or emergency brakes that use spring pressure spring brakes are used in trucks truck tractors and buses as emergency in parking brakes they are held by mechanical force Springs which is vital because air pressure can eventually leak away when air pressure is removed or lost the Springs activate the brakes this feature provides a failsafe mechanism in case of an air brake system leak front wheeel brakes are good under all conditions true or false answer B false front wheeel brakes are generally effective but their effectiveness can vary under different conditions some older vehicles pre-1975 have a front brake limiting valve used to reduce front brake pressure by half in Slippery conditions to prevent front wheel skidding however it's been found that front wheeel braking is generally reliable even on ice and such limiting valves actually reduce the overall stopping power of the vehicle how do you know if your vehicle is equipped with antiock brakes a by checking the brake padal b by the presence of an ABS light on the dashboard C by testing the brakes on a slippery Road D by looking at the size of of the tires answer B by the presence of an ABS light on the dashboard vehicles with anti-lock braking systems ABS have a distinctive ABS light on the dashboard this system required in truck tractors with air brakes built on are after March 1st 1997 and in other vehicles with air brakes built on are after March 1st 1998 prevents will lock up during heartbreak application the ABS light indicates whether the system is functioning properly what is a dual air brake system a a system with two sets of brakes for each wheel b a brake system that uses both air and hydraulic fluid c a system with two separate air brake systems using a single set of brake controls d a brake system that operates in two different modes depending on the load answer c a system with two separate air brake systems using a single set of brake controls a dual air brake system consists of two independent air brake systems which control the brakes but they are managed through a single set of brake controls what are the slack adjusters a devices that increase air pressure in the brakes B levers connected to the brake that adjusts the tension on the brake shoes C sensors that detect when the brakes are applied D valves that release excess air from the brake system answer B levers connected to the brake that adjusts the tension on the brake shoes slack adjusters are an essential component of an air brake system they are levers attached to the brakes and play a crucial role in maintaining the correct distance between the brake shoes and the drum over time as the brake shoes wear down the slack adjuster compensates for this where by adjusting the tension ensuring consistent braking efficiency how can you check slack adjusters a by listening to the sound they make when brakes are applied B by measuring the air pressure in the brake system C by pulling on them to see if they move more than about 1 in D by checking the brake fluid level answer C by pulling on them to see if they move more than about 1 inch checking slack adjusters is a crucial part of air bra system maintenance this involves manually pulling on the slack adjusters to measure their movement if a slack adjuster moves more than about 1 in it may indicate that it is out of adjustment or that there is exessive wherein the brake components regular checks ensure that the brakes remain effective and safe how can you test the low pressure warning signal a by applying the brakes rapidly B by reducing the air pressure in the system to see if the warning signal comes on C by checking the electrical connections to the signal d by measuring the temperature of the air compressor answer B by reducing the air pressure in the system to see if the warning signal comes on the low air pressure warning signal is a critical safety feature in air brake systems testing it involves intentionally reducing the air pressure in the brake system to trigger the warning signal which usually consists of a light and or buzzer this test confirms the warning system activates properly at the designated pressure pressure level typically around 60 PSI to alert the driver of potentially dangerous low air pressure conditions how can you check that the spring Brakes come on automatically a by driving at a high speed and then breaking hard B by applying and releasing the parking brake C by draining air from the system to a low pressure level d by checking the spring tension in the brakes answer C by draining air from the system to a low pressure level spring brakes used as parking and emergency brakes in large Vehicles automatically activate when air pressure drops below a certain level to check their operation the air pressure in the brake system is deliberately reduced typically by draining air from the tanks when the pressure Falls to a low level the spring brakes should automat aut atically engage this test ensures that the spring brakes will function correctly in an emergency or when the vehicle is parked what are the maximum leakage rates a the maximum rate at which air can be added to the system B the maximum distance the vehicle can travel with a leak C the maximum rate at which air can leak from the system without failing the test D the maximum time that breaks can be applied continuously answer C the maximum rate at which air can leak from the system without failing the test the maximum leakage rate is a critical measure in air brake system maintenance it refers to the highest permissible rate at which air can escape from the system without indicating a failure during a leakage test these rates are specified by regulations and are essential for ensuring the air brake system maintains sufficient pressure for safe operation why should you be in the proper gear before starting down a hill a to prevent the engine from overheating B to maintain control and avoid overusing the brakes C to increase fuel efficiency D to prepare for sudden stops answer B to maintain control and avoid overusing the brakes being in the proper gear before descending a hill is crucial for maintaining control of the vehicle this allows the engine braking to assist in slowing the vehicle reducing the Reliance on the service brakes overusing brakes on a descent can lead to overheating and reduced braking efficiency potentially leading to break failure what factors can cause brakes to fade or fail a excessive use overheating and low air pressure B cold weather conditions C improper alignment of Wheels d low tire pressure answer a excessive use overheating and low air pressure brake fade or failure can occur due to excessive use leading to overheating and low air pressure the brake system overheating particularly on long or steep descents can reduce the friction of the brake pads while low air pressure can affect the brakes ability to apply sufficient Force the use of brakes on along steep downgrade is only a supplement to the braking effect of the engine true or false answer a true when descending along long steep grade the primary method of controlling the vehicle speed should be the engine braking or retarder systems the service brakes should only be used as a supplement to these systems to prevent overheating and ensure they remain effective when needed if you are away from your vehicle only a short time you do not need to use the parking brake true or false answer B false the parking brake should always be used when the vehicle is parked regardless of the duration this is a necessary safety precaution to prevent the vehicle from Rolling away which can be a severe safety hazard how often should you drain air tanks a weekly B monthly C at the end of each working day D once every few hours of driving driving answer C at the end of each working day air tanks in an air BR system should be drained at the end of each working day this routine maintenance removes moisture and oil buildup which can affect the performance of the air brake system and lead to potential failures how should you break when you drive a tractor trailer combination with abs a use only the tractor brake not the trailer brakes B breake harder than you would without ABS C apply steady pressure to the brake pedal D pump the brakes to prevent locking answer C apply steady pressure to the brake padal when driving a tractor trailer equipped with an antiock braking system ABS the correct method of braking is to apply steady pressure to the brake pedal ABS is designed to prevent will lock up during heartbreaking by automatically modulating brake pressure this system allows the driver to maintain steering control during an emergency stop especially on slippery surfaces you still have normal brake functions if your abs is not working true or false answer a true it's the ABS on a vehicle is not functioning the standard braking system of the vehicle Still Remains operational ABS is an additional safety feature that operates independently of the main braking system its primary role is to prevent the wheels from locking up during emergency braking especially under slippery conditions however if the ABS Mal functions the basic hydraulic braking system of the vehicle is still intact and functional what are the three different braking systems mentioned in air brakes a service brake parking brake and hydraulic brake b service brake parking brake and emergency brake C hydraulic brake electric brake and parking brake d emergency brake antiock brake and service brake answer B service brake parking brake and emergency brake in air brake systems there are typically three different braking systems service brake this is the primary braking system used during normal driving it is operated using the brake paddle to apply and release the brakes it controls the speed of the vehicle and brings it to a stop parking brake this system is used to keep the vehicle stationary when it is parked it is mechanically operated and holds the vehicle stationary even if air pressure is lost emergency breake this system is designed to engage automatically in the event of a loss of air pressure in the service brake system it acts as a safety feature to stop the vehicle during an emergency if the service brake fails what is the purpose of the service brake system in air brakes a to keep the vehicle stationary when parked B to apply and release the brakes during normal driving using the brake paddle C to engage the brakes in case of an air pressure loss D to control the braking when pulling a trailer answer B to apply and release the brakes during normal driving using the brake paddle the service brake system in air brakes is the main braking mechanism used under under normal driving conditions it is operated by the driver through the brake padal when the driver presses the brake pedal air pressure is directed to the brake Chambers causing the brakes to engage and slow the vehicle releasing the pedal reduces the air pressure allowing the brakes to disengage air brakes use which of the following to operate a hydraulic fluid B engine power C electric current D compressed air answer D compressed air air brakes operate using compressed air this system utilizes an air compressor to build up air pressure which is then stored in air tanks when the brake paddle is pressed this compressed air is delivered to the brake Chambers activating the brakes the use use of compressed air makes these brakes powerful and effective for large commercial vehicles which system in air BR supplies and releases the brakes during normal driving a parking brake system B emergency brake system C service brake system D hydraulic brake system answer C service brake system the service brake system in air brakes is the primary system used for regular driving operations it is controlled by the brake pedal inside the cab when the driver presses the brake pedal compressed air is channeled to the brake Chambers causing the brakes to engage and slow the vehicle down what is the purpose of the emergency brake system in air brakes a to automatically adjust the brake pressure B to engage when the regular brakes fail C to provide additional braking power during normal driving D to reduce the brake temperature answer B to engage when the regular brakes fail the emergency brake system in air brakes is designed as a backup safety mechanism it activates automatically in case of a failure in the service break system such as a significant loss of air pressure which of the following is a key aspect of air bra maintenance a regular tire rotation B frequent oil changes C ensuring proper air pressure D checking the electrical system answer C ensuring proper air pressure maintaining the correct air pressure is crucial for the effective operation of air brakes regular checks and adjustments are necessary to ensure that the air compressor is functioning correctly and that there are no leaks in the system proper air pressure is essential for the brakes to function correctly and safely as it is the force that activates the brake mechanisms

Channel: MyTestMyPrep

Views: 39,560

Keywords: Online, Course Prep, Tutor, test prep, tutoring, online course, preparation, classes, lessons, free tutoring video, review practice tests, CDL Exam 2024, Truck Driving, Commercial Driver's License, CDL Preparation, CDL Air Brake Endorsement, Trucking, CDL Study Guide, Air Brake System, Air Brake Mechanics, CDL Training, Truck Driving School, CDL Test Prep, Commercial Driving, Air Compressor, Brake Maintenance, Emergency Braking, CDL Study Tips, Truck Driver Training

Id: QxCprq8baQc

Length: 20min 27sec (1227 seconds)

Published: Sun Dec 10 2023