1.
The principle behind hydraulic brakes is _________________, which states that pressure applied to a fluid in one part of a closed system will be transmitted without loss to all other areas of the system.
Correct Answer
C. Pascal's law
Explanation
Pascal's law states that pressure applied to a fluid in one part of a closed system will be transmitted without loss to all other areas of the system. This principle is the basis for hydraulic brakes, where the pressure applied to the brake pedal is transmitted through the brake fluid to the brake calipers, causing the brake pads to press against the rotors and slow down the vehicle.
2.
A substantial leak in the _____________ will prevent enough pressure from building to exert the necessary braking force
Correct Answer
D. Hydraulic system
Explanation
A substantial leak in the hydraulic system will prevent enough pressure from building to exert the necessary braking force. The hydraulic system is responsible for transmitting force from the brake pedal to the brake pads or shoes, allowing them to create friction and slow down or stop the vehicle. If there is a leak in the hydraulic system, the pressure required for effective braking will not be maintained, resulting in a loss of braking power.
3.
Which of the following variables is related to pressure and force in a hydraulic system?
Correct Answer
D. All the above
Explanation
All the variables mentioned in the options, namely input force, working pressure, and output force, are related to pressure and force in a hydraulic system. The input force refers to the force applied to the hydraulic system, the working pressure represents the pressure exerted within the system, and the output force is the force generated by the system. Therefore, all of these variables play a role in understanding and analyzing the pressure and force dynamics in a hydraulic system.
4.
Which of the following is a main component of a typical hydraulic brake system?
Correct Answer
D. All of the above
Explanation
All of the options listed are main components of a typical hydraulic brake system. The brake pedal is the input device that the driver uses to apply pressure to the brakes. Brake fluid is the medium that transfers the force from the brake pedal to the brakes themselves. The master cylinder is responsible for converting the mechanical force from the brake pedal into hydraulic pressure in the brake fluid. Therefore, all of these components are essential for the proper functioning of a hydraulic brake system.
5.
Which of the following is a property of typical brake fluid used in automobile brake systems?
Correct Answer
D. All of the above
Explanation
Brake fluid used in automobile brake systems typically has a high boiling point, which means it can withstand the high temperatures generated during braking without vaporizing. It also has a low freezing point, ensuring that it remains in a liquid state even in cold temperatures. Additionally, brake fluid is hygroscopic, meaning it has the ability to absorb moisture from the air, preventing the formation of water droplets that could cause corrosion or brake failure. Therefore, all of the given options are properties of typical brake fluid used in automobile brake systems.
6.
Brake fluid is graded by the Department of Transportation on which of the following?
Correct Answer
B. pH value
Explanation
Brake fluid is graded by the Department of Transportation based on its pH value. The pH value of brake fluid determines its acidity or alkalinity. This is important because the pH level affects the efficiency and performance of the brake fluid in the braking system. Brake fluid with the correct pH level ensures proper lubrication and protection of the brake system components, preventing corrosion and maintaining optimal braking performance. Therefore, the pH value is a crucial factor in determining the grade of brake fluid.
7.
Determining if brake fluid should be flushed can be done using which of the following methods?
Correct Answer
D. All of the above
Explanation
All of the above methods can be used to determine if brake fluid should be flushed. A test strip can be used to measure the moisture content in the brake fluid, which can indicate if it needs to be changed. The DVOM-galvanic reaction test can be used to measure the voltage difference between the brake fluid and a reference electrode, which can also indicate if it needs to be flushed. Finally, time and mileage can be used as general indicators for when brake fluid should be changed, as it is recommended to be done every 2-3 years or 30,000-45,000 miles.
8.
A typical brake pedal inspection includes which of the following?
Correct Answer
D. All the above
Explanation
A typical brake pedal inspection includes checking the brake pedal height, which ensures that it is at the correct position for comfortable and efficient operation. The inspection also involves checking the brake pedal free play, which is the amount of movement the pedal has before it starts to engage the brakes. Lastly, the inspection includes checking the brake pedal travel, which is the distance the pedal travels when the brakes are applied. Therefore, all of the above options are included in a typical brake pedal inspection.
9.
A(n) ____________________ (non-CAN-bus) circuit is a simple light bulb in series with as many as four switches that are connected in parallel with each other.
Correct Answer
B. Mechanical brake warning lamp system
Explanation
A mechanical brake warning lamp system is a circuit that consists of a simple light bulb connected in series with up to four switches that are connected in parallel with each other. This means that the light bulb will only illuminate if any of the switches are activated, indicating a problem with the mechanical brake system. This system does not involve the use of a CAN-bus, which is a type of communication network commonly used in modern vehicles. Therefore, the correct answer is mechanical brake warning lamp system.
10.
True or False. To ensure that a leak in one brake circuit will not affect the other circuit, master cylinder reservoirs have two separate chambers.
Correct Answer
A. True
Explanation
To ensure that a leak in one brake circuit will not affect the other circuit, master cylinder reservoirs have two separate chambers. This is true because having two separate chambers allows for the separation of fluid for each brake circuit. In the event of a leak in one circuit, the other circuit will still have an adequate amount of fluid to function properly, ensuring the safety and effectiveness of the braking system.
11.
Most modern master cylinder reservoirs are equipped with a low brake fluid float switch that turns on the __________________ on the instrument panel and/or sets a notification on the driver information system.
Correct Answer
C. Red brake warning light
Explanation
Most modern master cylinder reservoirs are equipped with a low brake fluid float switch that turns on the red brake warning light on the instrument panel and/or sets a notification on the driver information system. This warning light is typically red in color to indicate a potentially serious issue with the brake system, such as low brake fluid level or a malfunctioning brake system component. It alerts the driver to take immediate action and have the brake system inspected and repaired to ensure safe driving conditions.
12.
___________________ carry brake fluid from the master cylinder to the brake units.
Correct Answer
C. Doubled-walled steel lines and rubber hoses
Explanation
The correct answer is doubled-walled steel lines and rubber hoses. This is because brake fluid needs to be transported from the master cylinder to the brake units, and both double-walled steel lines and rubber hoses are commonly used for this purpose. Double-walled steel lines provide durability and resistance to corrosion, while rubber hoses offer flexibility and absorb vibrations. Therefore, a combination of both is often used to ensure efficient and reliable brake fluid transportation.
13.
Brake hoses should never be?
Correct Answer
D. All of the above
Explanation
Brake hoses should never be pinched, kinked, or bent tighter than a specific radius. These actions can restrict or block the flow of brake fluid, leading to brake failure. Pinching or kinking the hose can cause damage to the inner lining or outer cover, leading to leaks or ruptures. Bending the hose tighter than the specified radius can cause the hose to collapse or restrict fluid flow, compromising the effectiveness of the braking system. Therefore, all of the mentioned actions should be avoided to ensure the proper functioning of the brake system.
14.
Tech A says that proportioning valves reduce brake pressure to the rear wheels and are pressure-sensitive or load-sensitive. Tech B says that load-sensitive proportioning valves adjust rear brake pressure according to the weight of the vehicle's load. Who is correct?
Correct Answer
C. Both Techs A and B
Explanation
Both Techs A and B are correct. Proportioning valves are indeed used to reduce brake pressure to the rear wheels, and they can be pressure-sensitive or load-sensitive. Load-sensitive proportioning valves specifically adjust the rear brake pressure based on the weight of the vehicle's load. Therefore, both Tech A and Tech B are providing accurate information.
15.
True or False. Many brake hoses use banjo fittings to connect the hose to the wheel unit.
Correct Answer
A. True
Explanation
Many brake hoses use banjo fittings to connect the hose to the wheel unit. Banjo fittings are commonly used in brake systems because they provide a secure and leak-free connection. The design of banjo fittings allows for a flexible hose to be attached at a right angle to the brake caliper or wheel cylinder, ensuring proper alignment and efficient fluid transfer. This type of fitting also allows for easy installation and removal, making it a popular choice in automotive brake systems. Therefore, the statement "Many brake hoses use banjo fittings to connect the hose to the wheel unit" is true.
16.
Banjo-type fittings typically include?
Correct Answer
D. All of the above
Explanation
Banjo-type fittings typically include a banjo fitting, which is a hollow bolt with a hole through the middle, allowing fluid to flow through. They also include a banjo bolt, which is used to secure the banjo fitting in place. In addition, two copper or aluminum washers are typically used with banjo-type fittings to create a tight seal and prevent leaks. Therefore, the correct answer is "All of the above" as all of these components are commonly found in banjo-type fittings.
17.
Tech A says that a cracked brake hose that is not leaking does not need to be replaced. Tech B says that a brake hose with a blister must be replaced. Who is correct?
Correct Answer
B. Tech B
Explanation
Tech B is correct. A cracked brake hose that is not leaking may still be compromised and pose a safety risk. It is recommended to replace a cracked brake hose to ensure the integrity of the braking system. Additionally, a brake hose with a blister indicates damage and should be replaced to prevent potential failure. Therefore, both statements made by Tech B are accurate.
18.
Tech A says that if none of the brake lights illuminate when depressing the brake pedal, the problem could be the fuse or bulbs. Tech B says that if none of the brake lights illuminate when depressing the brake pedal, the problem could be the feed wire or ground. Who is correct?
Correct Answer
C. Both Techs A and B
Explanation
Both Techs A and B are correct. If none of the brake lights illuminate when depressing the brake pedal, the problem could be caused by either a blown fuse or faulty bulbs (as mentioned by Tech A) or a problem with the feed wire or ground (as mentioned by Tech B). Both possibilities should be considered when troubleshooting the issue.
19.
All of the following are methods used to force air and contaminated fluid out of a brake system in a vehicle, EXCEPT:
Correct Answer
C. Bench bleeding.
Explanation
Bench bleeding is a method used to remove air from the master cylinder of a brake system before it is installed in a vehicle. It involves attaching hoses and submerging the master cylinder in a container of brake fluid, then manually pumping the cylinder to force out any air bubbles. This is done to ensure that the master cylinder is properly primed and does not introduce air into the brake system when installed. Vacuum bleeding, pressure bleeding, and manual brake bleeding are all methods used to remove air and contaminated fluid from the brake system of a vehicle after it is installed.
20.
Which of the following can turn on the brake warning light?
Correct Answer
D. All of the above
Explanation
All of the options listed can turn on the brake warning light. When the parking brake is engaged, it activates the brake warning light as a reminder to disengage it before driving. If the brake fluid level is low, it can indicate a potential problem with the braking system, causing the brake warning light to turn on. Similarly, if there is unequal pressure in the brake system, it can also trigger the brake warning light to alert the driver of a potential issue. Therefore, all of the given options can individually or collectively turn on the brake warning light.
21.
Tech A says that as moisture levels increase in brake fluid, the boiling point of the brake fluid decreases. Tech B says that field tests by the Society of Automotive Engineers have documented that the average 1-year-old car has approximately 2% moisture in the brake fluid. Who is correct?
Correct Answer
C. Both Techs A and B
Explanation
Both Techs A and B are correct. Tech A is correct because as moisture levels increase in brake fluid, the boiling point of the brake fluid does indeed decrease. Moisture can enter the brake fluid through various means such as condensation or leaks, and this can lower the boiling point of the fluid, potentially leading to brake failure. Tech B is correct because field tests by the Society of Automotive Engineers have indeed shown that the average 1-year-old car has approximately 2% moisture in the brake fluid. This moisture can accumulate over time and affect the performance of the brake system.
22.
Tech A says that using gasoline is an approved method of cleaning brake system components. Tech B says that using kerosene is an approved method of cleaning brake system components. Who is correct?
Correct Answer
D. Neither Tech A nor B
Explanation
Neither Tech A nor Tech B is correct. Using gasoline or kerosene to clean brake system components is not an approved method. Brake system components should be cleaned using brake cleaner or a specific brake cleaning solution recommended by the manufacturer. Gasoline and kerosene can leave residue or damage the rubber seals and other parts of the brake system, compromising its performance and safety.
23.
Tech A says that when replacing a brake master cylinder, it should be bled after placing the master cylinder into the vehicle's brake system. Tech B says that when replacing a master cylinder, it should be bench bled before the master cylinder is placed into the vehicle's brake system. Who is correct?
Correct Answer
B. Tech B
Explanation
Tech B is correct. When replacing a brake master cylinder, it should be bench bled before it is placed into the vehicle's brake system. Bench bleeding involves filling the master cylinder with brake fluid and then using a tool to pump the fluid through the cylinder to remove any air bubbles. This ensures that there are no air pockets in the master cylinder which could cause a loss of brake pressure or a spongy brake pedal. Once the master cylinder is bench bled, it can be installed into the vehicle's brake system and then the entire brake system should be bled to remove any air that may have entered during the installation process.
24.
Tech A says that if there is too much travel in the parking brake lever, the cables should be shortened. Tech B says that if there is too much travel in the parking brake lever, the parking brake (drum or disc) clearance should be checked. Who is correct?
Correct Answer
B. Tech B
Explanation
Tech B is correct. If there is too much travel in the parking brake lever, it indicates that the parking brake (drum or disc) clearance should be checked. Shortening the cables, as suggested by Tech A, would not address the issue of excessive travel in the parking brake lever.
25.
Tech A says that in a CAN-bus circuit the parking brake sensor and the low brake fluid sensors send signals over the CAN-bus network regarding their status. Tech B says that diagnosis involves using a scan tool capable of interrogating the system, a wiring diagram, and a DVOM to perform specific tests. Who is correct?
Correct Answer
C. Both Techs A and B
Explanation
Both Techs A and B are correct. Tech A is correct in stating that the parking brake sensor and the low brake fluid sensors send signals over the CAN-bus network regarding their status. Tech B is correct in stating that diagnosing issues with the CAN-bus circuit involves using a scan tool capable of interrogating the system, a wiring diagram, and a DVOM (Digital Volt Ohm Meter) to perform specific tests. Both pieces of information provided by Tech A and Tech B are accurate and relevant to understanding the functioning and diagnosis of a CAN-bus circuit.