CDX Brakes midterm answers
which of the following statements is true with respect to parallelism
0.0003
if 100psi of working pressure is applied to a 2 square inch output piston, how much force will be created?
200
Tech A says that brake fluid should periodically be checked for excessive moisture content. Tech B says that brake fluid should be replaced every 12000 miles.
Tech A
all of the following statements with respect to wear indicators are true except
a electrical contacts cannot be manufactured into the pad, so they have to clipped to the pad
Tech A says that chrome plated pistons resist rust. tech B says that pistons made of phenolic resin do not corrode and transmit less heat.
both A and B
among the tools used to diagnose and repair drum brakes systems, the wheel cylinder piston clamp is used to
hold the pistons in the wheel cylinder while the brake shoes are removed
the kind of brake fade caused by the brake fluid becoming so hot that it boils is
hydraulic fade
If we triple the speed of an object, the kinetic energy will:
increase by nine times
when a vacuum-type power booster is used, the driver will be required to increased foot pressure to activate the brakes if there is
insufficient vacuum
which of the following flares is created by first flaring the end of the tube outward in a Y shape?
inverted double flare
disc brake systems that are equipped with low-drag brake calipers use:
quick take-up master cylinders
all of the following statements with respect to replacing brake lines, brake hoses, fittings, and supports are true except
reassemble the removed components using tools only
when the driver releases the brake pedal, the brake shoes are withdrawn bt the
return spring
which of the following materials have the highest coefficient of friction?
rubber and concrete
which of these is a simple mechanical system that uses leverage to force a friction block against one or more wheels?
scrub brake
Tech A says that DOT 5 brake fluid should be used in all vehicles today because it is silicone based and will not absorb water. Tech B says that DOT 4 and DOT 3 are not recommended for use in ABS systems.
Neither A or B
Tech A says that a sinking brake pedal is an indication of a faulty vacuum booster. Tech B says that the master cylinder can only have external leaks not internal leaks.
Neither A or B
Tech A says that the metering valve controls pressure to the rear brakes. Tech B says that the proportioning valve controls pressure to the front brakes
Neither A or B
All of the below statements are true except:
In drum brakes, the heat is created outside of the drum and transferred to the inner surface
Tech ! says that an antilock brake system (ABS) allows the front wheels to be steered during a panic stop. Tech B says that ABS sensors apply or release hydraulic pressure to the wheel brake units during ABS brake events.
Tech A
Tech A says that a disc brake operates by clamping friction materials to the outside of a disc. Tech B says that a drum brake operates by clamping friction materials to the outside of a drum.
Tech A
Tech A says that a faulty vacuum booster can affect engine operation. Tech B says that steel brake line can be replaced with a copper line as it is easier to bend into shape.
Tech A
Tech A says that brake fluid should periodically be checked for excessive moisture content. Tech B says that brake fluid should be replaced every year.
Tech A
Tech A says that light-duty service are typically applied hydraulically. Tech B says that light-duty parking brakes are typically applied hydraulically.
Tech A
Tech A says that the brake pedal uses leverage to multiply foot pressure. TEch B says that when braking hard while moving forward, the vehicle's weight transfer to the rear wheels, increasing their traction
Tech A
Tech A says that the low level brake fluid switch on a master cylinder turn on the brake warning light when the system is low on fluid. Tech B says that the low level switch also monitors the condition of the fluid and activates the warning light when the brake fluid needs to be replaced.
Tech A
Tech A says that the secondary piston in a master cylinder is operated by hydraulic force. Tech B says that the brake pedal return spring returns the master cylinder pistons to their original position.
Tech A
Tech A says that a brake pedal that does not return all the way causes the brake warning light on the instrument panel to stay on. Tech B says that a brake pedal that does not return causes the brake lights to stay on.
Tech B
Tech A says that a service brake pedal that does not return all the way causes the brake warning light on the instrument panel to stay on. Tech B says that a service brake pedal that does not return causes the brake lights to stay on.
Tech B
Tech A says that bench bleeding a master cylinder prevents having to bleed air from the brake lines during replacement. Tech B says that bench bleeding the master cylinder makes bleeding the brakes on the vehicle easier.
Tech B
Tech A says that calipers use steel piston rings to seal each piston. Tech b says that calipers use a square section O-ring to seal each piston.
Tech B
Tech A says that kinetic energy is created during braking to stop the vehicle. Tech B says that kinetic energy is converted to heat energy during braking.
Tech B
Tech A says that quick take-up master cylinders use two additional pistons to move brake fluid faster. Tech B says that banjo fittings are commonly used to connect brake hoses to wheel brake units.
Tech B
Tech A says that tire pressure does not affect braking. Tech B says that heavy vehicle loads increase stopping distance.
Tech B
Tech A says that when flaring a brake lie, you should install the fitting onto the line after the line has been flared. Tech B says that when fabricating a double flare, the adapter widens and narrows the line and then the flaring tools folds the narrowed portion back into the widened portion of the flare.
Tech B
Tech A says that part of the hydraulic system diagnostic process could require disassembly and visual inspection or measurements of the suspected component or system. Tech B says that may involve performing tests in the ship with a scan tool, pressure gauges, or a DMM
both A and B
Tech A says that technicians have been successfully sued for improper brake repairs, resulting in large cash settlements. Tech B says that to reduce liability, good technicians create processes to help ensure steps of the job are not forgetten.
both A and B
Tech A says that brake pedal free play is the amount of clearance between the brake pedal linkage and the master cylinder piston. Tech B says that brake pedal travel is sometimes called reverse pedal
both a and b
tech a says that riveted lining is usually for heavy-duty or high-performance vehicles. tech b says that bonded lining is glued to the metal brake shoe.
both a and b
tech a says that rotors should be measure for thickness variation (parallelism). Tech b says that rotors should be measure for lateral runout.
both a and b
tech a says that some vehicles are equiped with a spring steel brake pad wear indicator that drags on the rotors when the lining thickness is low. tech b says that some vehcicles are equiped with an electrical brake pad wear sensor that activates a warning on the dash.
both a and b
tech a says that some vehicles use fixed calipers. tech b says that some vehicles use sliding/floating calipers
both a and b
tech a says that when performing a brake job on the rear axle of an older vehicle inspection finds brake fluid under the dust boot, the wheel cylinder should be replaced. tech b says that when a drum brake return spring has failed, springs on both rear wheels need to be replaced
both a and b
tech a that a metal on metal grinding noise in drum brakes generally requires replacing the brake shoes and resurfacing or replacing the drums
both a and b
when the brake pedal is depressed, a pushrod transfers the force to a hydraulic master cylinder through the
brake booster
all of the following statements are true with respect to brake fluid handling except
brake fluid is considered to be a top-off fluid
which of the following brake shoes when the drum is installed?
brake spoon
which of the following primary components of the disc brake system uses hydraulic pressure from the master cylinder to apply the brake pads?
caliper
the cycle of energy transformation in a typical vehicle is
chemical heat mechanical kinetic
The port that connects the reseervoir to the cylinder, just barely ahead of the primary cup is the
compensating port
Tech A says that a micrometer is used to measure rotor thickness variation. Tech B says that a micrometer is used to measure rotor lateral runout.
tech A
Tech A says that disc brake pads require higher application force than drum brake shoes. Tech B says that disc brakes are self-energizing.
tech A
Tech A says that disc brakes operate on the principle of friction. tech B says that disc brakes operate on the principle of regeneration.
tech A
Tech A says that to performance test a vacuum booster, start with the engine off, apply the brakes several times, hold the pedal down, start the engine, and observe the brake pedal action. Tech B says that to check a vacuum booster for internal leaks, you should pressurize the booster with compressed air and listen for leaks.
tech A
Tech A says that the vacuum booster increases the vacuum in the brake system. Tech B says that the vacuum booster uses vacuum and atmospheric pressure to multiply the driver's foot pressure applied to the master cylinder push rod.
tech B
tech a says taht most brake drums are designed to be machined if minor surface issues are present. tech b says brake drums can be reused if they are machined larger than specifications, as long as the surface is smooth
tech a
tech a says that duo- servo brake shoes are only anchored on the top. tech b says that duo-servo brakes typically use single-piston wheel cylinders.
tech a
tech a says that both secondary shoes should be installed on the passenger side of the vehicle. tech b says that the lining on the primary shoe is typically shorter in length than the lining on the secondary shoe
tech b
tech a says that brake shoe linings saturated with brake fluid from a leaky wheel cylinder can be cleaned with brake cleaner and reused as long as they arent worn out. tech b says that brake shoes should be replaced in axle sets.
tech b
tech a says that parking brakes on drum brakes vehicles uses separate brake shoes for back up in an emergency. tech b says that parking brakes on drum brakes vehicles mechanically operate the standard drum brake shoes.
tech b
tech a says to use an air hose to clean the backing plate of dust and contamination. tech b says to use a water-based cleanign solution to clean the backing plate of dust and contamination.
tech b
choose the correct statement
the backing plate has holes stamped in it.
The master cylinder should be inspected for internal and external leaks in all of the following scenarios
the brake pedal is harder to push than normal
what happens when bleeding is not done?
the brakes will feel spongy and will not be fully functional.
a wheel's braking ability depends most on:
the load it is carrying
All of the statements are true except:
the smaller brake caliper pistons on the front wheels give greater mechanical force and braking power to the front wheels
The brake pedal uses leverage:
to multiply the force applied to the master cylinder
in which type of parking brake does the rotor have a deeper offset than normal?
top hat design parking brake
vehicles equipped with disc brakes incorporate a mechanically operated drum-style parking brake in the center of the rear disc brake rotors, commonly called a:
top hat parking brake.
all of the following statements with respect to brake systems are true except:
trailing shoes are self- energizing
the component of the drum brake system attached to the backing plate is the
wheel cylinder
All of the below statements are true except:
A service brakes consist of drum and/or disc brakes and are operated by hand
Tech A says that friction brakes can fade due to overheating of the brake lining. Tech B says that friction brakes can fade due to overheating of the brake fluid.
Both A and B
Tech A says that hydraulic pressure is applied equally in all directions throughout a closed system. Tech B says that ain in the hydraulic system will cause the brake predal to be spongy.
Both A and B
Tech A says that input force divided by the area of the input gives working pressure. Tech B says that working pressure multiplied by the surface area of the output piston gives output force
Both A and B
Tech A says that the heavier the vehicle, the more stopping power is needed. TEch B says that the faster a vehicle is moving, the more braking power is needed
Both A and B
Tech A says that water soaked brake shoes can be a cause of brake fade. Tech B says that disc brakes dissipate heat faster than drum brakes.
Both A and B
which of the following brake fluids has the highest wet boiling point?
DOT 5
the following edge code letters correspond to four different brake friction materials. which of these has the lowest coefficient of friction?
EE
choose the correct statement
a riveted linings are used on heavier duty or high- performance
When performing a DMM-galvanic reaction test, the fluid should be flushed if it is
above 0.3V
which of the following is used on heavy vehicles and is commonly called air brake?
air operated braking system
In the case of possible petroleum contamination, which of the following can be used to flush brake fluid?
alcohol
which of these is an advantage of the disc brake system over drum brakes?
disc brakes reduce the likelihood of brake fade
all of the following statements with respect to the disc brake system are true except
drum brakes require higher applied forces than disc brakes
which of these drum brakes system uses servo action in both directions?
duo servo drum brake systems
Medium and heavy duty. vehicles often require increased braking in situations...........
exhaust brake
All of the following statements referring to disc brake calipers are true except
fixed calipers are the most common type is used in passenger vehicles
all of the following statements with respect to a wheel cylinder and pistons are true except
it is standard practice to hone out deep pits in the wheel cylinder bore
the component that prevents a direct path for water spary and first to enter the brake drum is
labyrinth seal
the valve that reduces rear brake pressure when the vehicle is lightly loaded and allows higher pressure when it is heavily loaded is
load-sensitive proportioning valve
different lever designs can be engineered to alter the brake pedal effort required of the driver by using different levels of:
mechanical advantage
which of the following is used to hold off the application of the front brakes on vehicles with disc brakes on the front wheels and drum brakes on the rear wheels?
metering valve
all of the following can be used to determine if the brake fluid should be flushed except
metering valve gauge
brake fluid testers are used to test the
moisture content of the brake fluid
Tech A says that fixed calipers use one or more pistons only on one side of the rotor. tech B says that sliding/fixed calipers use one or more pistons on both sides of the rotor.
neither a or b
tech a says that a cleaned-up self-adjuster can be installed on either side of the vehicle. tech b says that grease seals are meant to be reusable
neither a or b
which of the following test is used to verify brake booster operation and involves starting the engine while measuring the pedal height?
performance test
