Question 1

The purpose of the master cylinder is to ______.

Accepted Answer

The master cylinder generates the hydraulic pressure needed to apply the brake mechanisms, converting the mechanical force from the brake pedal into hydraulic pressure. Choices B and C describe functions not directly performed by the master cylinder.

Question 2

Since _____, all cars have been required to have two separate brake systems.

Accepted Answer

Since 1967, all cars have been required to have two separate brake systems to enhance safety by ensuring that if one system fails, the other can still function to stop the vehicle.

Question 3

The amount of pressure exerted by the brakes is being discussed. Technician A says short brake lines generate more pressure than long brake lines. Technician B says the condition of the piston seals in the master cylinder influences the amount of pressure developed. Who is correct?

Accepted Answer

The condition of the piston seals in the master cylinder is crucial for maintaining proper hydraulic pressure in the brake system. The length of the brake lines does not affect the pressure generated, as hydraulic systems transmit pressure equally throughout.

Question 4

What could most likely lead to brake hose failure?

Accepted Answer

Stressing the hose during installation can cause physical damage or weakening, leading to failure.

Question 5

______ friction is generated between the brake pads and rotors when the vehicle is descending a steep hill.

Accepted Answer

Kinetic friction occurs between moving surfaces, such as brake pads and rotors, when a vehicle is in motion, including descending a hill.

Question 6

While manually bleeding a brake system, Technician A loosens all the brake bleeder screws at the same time. Technician B uses shop air to push the fluid and air through the lines and out the bleeder screws. Who is correct?

Accepted Answer

Manually bleeding a brake system typically involves opening and closing the bleeder screws one at a time, not all at once, to ensure proper removal of air from each brake line. Using shop air directly can introduce more air into the system or damage components due to excessive pressure.

Question 7

In a diagonal split brake system, how would the vehicle brake in the event of a failure?

Accepted Answer

In a diagonal split brake system, if there's a failure, one front wheel and the opposite rear wheel will still brake. This system is designed to maintain stability by ensuring that braking force is applied diagonally across the vehicle.

Question 8

Dissipation of heat from the brake components is necessary to prevent brake ______.

Accepted Answer

Dissipation of heat from brake components is crucial to prevent brake fade, which occurs when brakes lose effectiveness due to overheating.

Question 9

Which of the following fluids should be used in brake systems?

Accepted Answer

Brake systems require a specific type of fluid known as brake fluid, which is designed to operate under high pressure and temperature conditions. Power steering fluid, engine oil, and transmission oil are not suitable substitutes and can cause damage to the brake system.

Question 10

On a disc/drum system, the rear drum brakes lock up when the brake pedal is pressed hard. Technician A says the proportioning valve may not be functioning. Technician B says the axle height valve may be out of adjustment. Who is correct?

Accepted Answer

Both Technician A and Technician B are correct. The proportioning valve, which limits the pressure to the rear brakes to prevent lockup, may not be functioning properly. The axle height valve, which adjusts brake pressure based on the load and height of the vehicle, could also be out of adjustment, affecting brake performance.

Question 11

Technician A says a metering valve delays front braking until the rear brakes are applied. Technician B says a proportioning valve controls rear brake pressure, especially during moderate stops. Who is correct?

Accepted Answer

The answer of Technician A says a metering valve delays...

Question 12

What type of power-assist unit uses pressure developed by an external pump, such as a power steering pump?

Accepted Answer

Hydraulic-assist units use pressure developed by an external pump, such as a power steering pump, to assist in the operation of the system, making steering easier for the driver.

Question 13

Which of the following is NOT a component of a typical dual master cylinder?

Accepted Answer

A typical dual master cylinder does not include a pressure relief valve as a component. The primary piston, piston stop bolt, and secondary cup are standard parts of a dual master cylinder, which is used in braking systems to ensure redundancy and safety. The pressure relief valve is not a standard component of this system.

Question 14

All manufacturers recommend a specific sequence to follow when bleeding a vehicle's brakes.

Accepted Answer

Manufacturers often specify a particular sequence for bleeding brakes to ensure that air is properly removed from the brake system, which can vary depending on the vehicle's design.

Question 15

While discussing brake fluids, Technician A says hygroscopic brake fluid absorbs moisture from the air. Technician B says DOT 3 brake fluid has a higher boiling point than DOT 4 fluid. Who is correct?

Accepted Answer

Technician A is correct because hygroscopic brake fluid does absorb moisture from the air, which is a characteristic of brake fluids like DOT 3, DOT 4, and DOT 5.1. Technician B is incorrect because DOT 4 brake fluid actually has a higher boiling point than DOT 3 fluid, not the other way around.

Question 16

While discussing quick take-up master cylinders, Technician A says this design is used with low-drag caliper pistons. Technician B says this design is only used on disc brake systems. Who is correct?

Accepted Answer

Quick take-up master cylinders are designed to work with low-drag caliper pistons and are typically used in disc brake systems to improve performance and reduce drag.

Question 17

Which of the following could cause an extremely hard brake pedal?

Accepted Answer

A leaking diaphragm in the vacuum power booster can cause an extremely hard brake pedal because it reduces the power assist to the braking system, making the pedal much harder to press.

Question 18

Power brakes are completely different than a standard hydraulic brake system, using different types of master cylinders, calipers, and hydraulic circuits.

Accepted Answer

Power brakes enhance the force applied to the brake pedal through a power booster but still use the same basic components such as master cylinders, calipers, and hydraulic circuits as a standard hydraulic brake system.

Question 19

The power brakes in a vehicle are grabbing. Technician A checks for grease or oil on the brake shoe and pad linings. Technician B checks the fluid level in the master cylinder. Who is correct?

Accepted Answer

Grabbing brakes can be caused by contamination such as grease or oil on the brake shoe and pad linings, which Technician A is checking for. Checking the fluid level in the master cylinder, as Technician B is doing, is not directly related to grabbing brakes.

Question 20

The purpose of a pressure differential valve is being discussed. Technician A says it alerts the driver if pressure is lost in either portion of a dual braking system. Technician B says it provides the needed pressure balance between the front and rear brakes. Who is correct?

Accepted Answer

The pressure differential valve is designed to alert the driver if there is a loss of pressure in one part of a dual braking system, which is what Technician A stated. Technician B's statement is incorrect as the valve does not balance pressure between front and rear brakes.

Quiz 50: Brake Systems