Brake Systems Chapter quizzes
ABS system bleeding is being discussed. Technician A says a scan tool must be used to bleed some ABS. Technician B says the base brakes and the ABS must be bled together. Who is correct?
A only
Diagnosing an integral ABS system is being discussed .Technician A says some integral ABS systems have a high pressure accumulator. Technician B says some integral ABS systems use high pressure power steering fluid for brake assist. Who is correct?
A only
Shared components among ABS and TCS are the wheel speed sensors and hydraulic modulator.
False
Technician A says DOT 3 and DOT 4 brake fluids have a higher boiling point than DOT 5. Technician B says DOT 4 brake fluid has a higher wet boiling point than DOT 5. Who is correct?
Neither A or B
A low brake pedal could be caused by worn brake shoes or a defective brake shoe adjuster.
True
The best way to test a wheel speed sensor is with an oscilloscope.
True
The most common diameters for steel tubing in the inch system are 3/16-inch, 1/4-inch, and 6/16-inch range.
True
The proportioning valve is located in the hydraulic line to the rear brakes.
True
Technician A says tire inflation monitoring is part of the ABS on some vehicles. Technician B says the parking brake is part of the ABS on some vehicles. Who is correct?
A only
Which of the following is a four-channel ABS system?
Bosch ABS 9.0
___________ is the number of times a cycle occurs within one second.
Frequency
A history code indicates a full-time problem that is difficult to diagnose.
False
Most ABS will only allow partial operation of the service brakes if the ABS has a fault.
False
All Delphi DBC-7 systems are four-channel systems.
Flase
The master cylinder is an apply piston.
True
Technician A says the parking brake should hold the vehicle on a 30 percent grade in both the forward and reverse directions. Technician B says the parking brake must be able to stop a vehicle moving 5 mph within 100 feet. Who is correct?
A only
Technician A says the first check of the suspension should be with the vehicle supported on a lift. Technician B says the first check of the suspension should be the springs through ride height. Who is correct?
B only
Technician A says the parking brake is part of the hydraulic braking system. Technician B says the parking brake is usually operated through a cable-and-lever system. Who is correct?
B only
Technician A says to calculate the coefficient of friction, measure the force required to slide an object over a surface and then divide it by the weight of the object. Technician B says the moving force that slides an object over a surface is tensile force. Who is correct?
B only
Brake friction materials are being discussed. Technician A says semi-metallic materials are made from a mix of organic or synthetic fibers and metals molded together. Technician B says ceramic pads provide suitable life, provide good stopping, and reduce changes of fading, but they retain heat. Who is correct?
Both A and B
Technician A says glazed or worn linings are the most common cause of drum brake problems. Technician B says such problems include hard pedal, pulling to one side, wheel locking, brake chatter, excessive pedal travel, noisy brakes, grabbing brakes, or little or no braking power. Who is correct?
Both A and B
Technician A says if you are troubleshooting a brake pull problem and cannot pinpoint the cause, try driving the car in reverse and applying the brakes. Technician B says if the car pulls in opposite directions while braking in forward and reverse, look closely for loose or broken suspension and steering components. Who is correct?
Both A and B
Technician A says the hydro-boost fluid reservoir for the pump may be remote from the pump location. Technician B says the controller, master cylinder, pump, and reservoir are included in a single unit. Who is correct?
Both A and B
Technician A says the seal around the piston is used to seal the hydraulic pressure behind the piston. Technician B says the seal around the piston is used to retract the piston. Who is correct?
Both A and B
Technician A says the thrust angle is the angle between the geometric centerline and the thrust line. Technician B says the thrust line is the direction in which the rear wheels are pointing. Who is correct?
Both A and B
Technician A says the wheel cylinder has pressurized brake fluid applied to the pistons inside the cylinder. Technician B says the pistons act on the brake shoes to move them into contact with the brake drum. Who is correct?
Both A and B
Delphi DBC-7 systems are used almost exclusively on ____ vehicles.
General Motors
Which of the following is a true statement of parking brakes on a drum brake system?
The parking brake strut connects the primary shoe to the secondary shoe.
Fluid can return through the metering valve when the brakes are released.
True
The clamping action of frictional material in the rotating disc or rotor creates heat.
True
The rotor has a machined braking surface on each side.
True
All of the following statements about some electric parking brakes are true EXCEPT:
they apply when the vehicle is placed in drive.
Technician A says ISO flare fittings may have a different pitch thread depending on the make and model of the vehicle. Technician B says ISO flares tend to seal better while using more torque on the threaded nut. Who is correct?
A only
Technician A says internal rubber parts wear with age. Technician B says internal master cylinder leaks are caused by clogged ports. Who is correct?
A only
Technician A says rim width is measured between the inside surfaces of the rim flanges. Technician B says every tire has two rim widths on which it can be mounted. Who is correct?
A only
Technician A says the best possible traction and braking performance can be had with the treadless, slick tires used on race cars. Technician B says all street tires have a tread pattern of ribs and grooves that lets water be displaced from under the tire while still maintaining good traction. Who is correct?
Both A and B
In the following figure, which of the two items (A or B) indicates a worn ball joint?
Item B
A ________ is used to tell the brake actuator how fast and how far the driver applied the brake pedal.
Stroke sensor
A Technician should inspect all 4 tires before a road test.
True
Technician A says one piston of a dual master cylinder may supply pressure to one front wheel and one rear wheel. Technician B says a piston may supply pressure only to the brakes on one axle. Who is correct?
Both A and B
Technician A says reducing the coefficient of friction lowers the amount of force needed to move an object. Technician B says coefficient of friction is the relationship of tensile force to weight. Who is correct?
Both A and B
Technician A says the antilock controller or microprocessor is the computer for the ABS. Technician B says most automotive computers, including the EBCM, are programmed with an adaptive memory capability or learning mode. Who is correct?
Both A and B
Technician A says the wheel seal is removed with a seal puller. Technician B says the inner bearing is removed after the seal is removed. Who is correct?
Both A and B
Technician A says to test a typical parking brake, first gain access to the switch, which is often the hardest part of the job. Technician B says for lever-operated parking brakes, it may be necessary to remove all or part of the center console. Who is correct?
Both A and B
Technician A says leading-trailing brakes are also called full-servo brakes. Technician B says duo-servo brakes are also called non-servo brakes. Who is correct?
Neither A or B
Vacuum power brakes are being discussed. Technician A says vacuum on both sides of the diaphragm doubles the amount of force on the master cylinder pistons. Technician B says the return spring forces the diaphragm to the forward position when there is vacuum on both sides of the diaphragm. Who is correct?
Neither A or B
Technician A says a vehicle that has the tread wear indicators showing completely will likely hydroplane on wet roads. Technician B says the same condition should not affect braking on dry pavement. Who is correct?
A only
Technician A says active brakes can warn the driver of an impending crash. Technician B says active brakes do not actually apply the brakes if necessary to avoid a crash. Who is correct?
A only
Technician A says brake drums with moderate to severe scoring can be refinished by either turning on grinding on a brake lathe. Technician B says brake drums with moderate to severe scoring must be replaced. Who is correct?
A only
Technician A says most parking brake systems use a cable to connect the parking brake lever or pedal to the braking assemblies. Technician B says the cable assemblies are nonadjustable and must be replaced when the brake no longer works. Who is correct?
A only
Technician A says the caliper in the following figure has an integral parking brake. Technician B says the caliper in the following figure is used on the front axles. Who is correct?
A only
Technician A says the information presented in the following figure is based on recommendations from the Rubber Manufacturers Association. Technician B says one of the two diagrams can be found on the vehicle's tire placard. Who is correct?
A only
What type of mechanism keeps the parking brakes levers in the applied position?
A ratchet and pawl
Usually the speed sensor for a RWAL or RABS system was located on (in):
All of the above
A screw and nut assembly is used to:
Apply rear disc parking brakes
Magneto-resistive sensors are being discussed. Technician A says these sensors produce an AC voltage signal. Technician B says these sensors are supplied with voltage from the EBCM. Who is correct?
B only
Rear-wheel drive braking systems are being discussed. Technician A says this type of vehicle has separate drums and hubs on the front axle. Technician B says rear drums mount on a flange attached to the axle on RWD vehicles. Who is correct?
B only
Technician A says each manufacturer uses the same speed sensors to ease diagnostics. Technician B says each manufacturer and sometimes different ABS systems use different diagnostic procedures. Who is correct?
B only
Technician A says the test depicted in the illustration is for a ground side brake warning lamp switch. Technician B says the test shown can be used to check continuity of the switch in both the ON and OFF positions. Who is correct?
B only
Technician A says the wheel cylinder springs are return springs. Technician B says the shoe return springs push the pistons back in place. Who is correct?
B only
Brake bleeding ABS systems are being discussed. Technician A says that Some manufacturers state that either pressure bleeding or manual bleeding is acceptable for their various ABS installations. Others specify either one method or the other. Technician B says Use only the DOT 3, DOT 4, or synthetic brake fluid specified by the vehicle manufacturer. Who is correct?
Both A and B
Depressurizing accumulators is being discussed. Technician A says some systems are bled without depressurizing. Technician B says some systems must be depressurized before checking the fluid level. Who is correct?
Both A and B
Electrical parking brakes are being discussed. Technician A says some systems apply a drum-in-hat type brake. Technician B says some systems apply a disc brake. Who is correct?
Both A and B
Technician A says a stuck parking brake cable may cause a hard parking brake pedal with little braking affect. Technician B says a parking brake that holds only one wheel may have a broken equalizer. Who is correct?
Both A and B
Technician A says a wheel-mounted pressure sensor uses wireless communication to send the pressure signal to a PSB computer, which in turn, illuminates the warning light or icon in the dash. Technician B says factory sensors are usually installed in place of the regular tire valve stem. Who is correct?
Both A and B
Technician A says stoplight switches may be single-function or multifunction units. Technician B says the stop lamp switch is a normally open, momentary contact switch. Who is correct?
Both A and B
Technician A says the DBC-7 uses dynamic rear proportioning (DRP) to control rear brake pressure during normal braking. Technician B says the DBC-7 has two possible traction control systems: enhanced traction system (ETS) and TCS. Who is correct?
Both A and B
Which of the following is a leading trigger to turn on ABS warning lamps?
Dirty or damaged wheel speed sensors
Equalizer levers are used to reduce the effort of the driver applying the parking brakes.
False
Parking brake systems:
None of the above
Auxiliary drum parking brakes are contained inside the rotor of some rear disc brakes.
True
Integral parking brakes apply the service brake shoes or pads.
True
Most auxiliary drum parking brakes have manual star wheel adjusters similar to the adjusters on drum service brakes.
True
Some ABS accumulators have 2,600 psi of hydraulic pressure in the system whenever the ignition switch is on.
True
Some symptoms of premature ABS are clicking sounds from the BPMV, pump operation, and/or pedal pulsations, which occur with normal braking that usually does not activate the ABS system.
True
The caliper of a rear disc parking brake is activated by a mechanism that mechanically moves the caliper piston.
True
The friction material used for disc brake pads is generally harder than that used on drum brake linings.
True
The following illustration shows a:
screw-and-nut rear disc parking brake.
All of the following statements about rear drum parking brakes are true EXCEPT:
the lever forces the wheel cylinder pistons out to force the brake shoes against the drum.
The quick take-up master cylinder is a type of ____ master cylinder designed for some front-wheel drive cars.
Step bore
Brake tubing is being discussed. Technician A says tubing vibration could cause metal fatigue. Technician B says copper tubing may be used as brake tubing. Who is correct?
A only
Brake warning lights are being discussed. Technician A says a pressure differential in the brake system will switch on the light. Technician B says a typical switch for this light is tripped by vacuum. Who is correct?
A only
Electrical wiring repair is being discussed. Technician A says wire size is specified in either the American Wire Gauge (AWG) system or in a metric cross-sectional area. Technician B says the higher the number in AWG the higher the conductor. Who is correct?
A only
Sliding calipers are being discussed. Technician A says the pads and pistons move when the brakes are applied. Technician B says the caliper stays stationary as the brakes are released. Who is correct?
A only
Technician A says it is okay to replace both front brakes without replacing the rear brakes. Technician B says it is okay to replace the brakes on one side of an axle without replacing the other side. Who is correct?
A only
Technician A says that friction between the vehicles tires and the road is one factor in stopping the vehicle. Technician B says that a car with locked brakes stops in the shortest time possible. Who is correct?
A only
Technician A says that modern-day vehicles have split brake systems. Technician B says that all modern-day vehicles use a diagonal split system. Who is correct?
A only
Technician A says that too much torque on the lug nuts can warp a brake rotor. Technician B says that it is better to add additional torque to the lug nuts to prevent the wheel from falling off. Who is correct?
A only
Technician A says the frictional energy on the drum surface creates heat, and this heat is dissipated to the surrounding air as the drum rotates with the wheel. Technician B says the thinner a drum gets, the better its ability to absorb and release heat. Who is correct?
A only
Technician A says the pressure differential valve is a hydraulically operated switch that controls the brake failure warning lamp on the instrument panel. Technician B says the pressure differential valve came into use after the advent of ABS braking. Who is correct?
A only
Technician A says to diagnose a brake system that does not release, loosen the connection between the master cylinder and the brake booster. Technician B says if the brakes do not release when the master cylinder is removed from the booster, the booster is defective. Who is correct?
A only
Tire construction is being discussed. Technician A says the carcass of a tire consists of steel beads around the rim and layers of cords or plies that are bonded together to give the tire its shape and strength. Technician B says casing is the layer of rubber that contacts the road and contains a distinctive pattern to provide the desired traction. Who is correct?
A only
Technician A says force on the brake pedal is transmitted directly to the wheels by linkage. Technician B says pedal force is transmitted by hydraulic pressure generated in the master cylinder. Who is correct?
B Only
A vehicle has power assist during engine operation, but it has no assist after the engine has been off and during initial engine startup. Technician A says a stuck close vacuum check valve could be the cause. Technician B says a leaking vacuum check valve could be the cause. Who is correct?
B only
Electro-hydraulic brakes are being discussed. Technician A says these systems use a vacuum booster. Technician B says these systems share information with other electronic systems. Who is correct?
B only
Packing front wheel bearings is being discussed. Technician A says it is not necessary to repack the inner bearing since it is protected by the grease seal. Technician B says the grease seal should be replaced whenever the bearings are repacked or replaced. Who is correct?
B only
Technician A says all brake hoses are DOT approved. Technician B says some brake hoses are not DOT approved and you must check with your supervisor or parts vendor as to the hose warranty or desirability of using unapproved hose. Who is correct?
B only
Technician A says racing calipers may be made of cast aluminum because it allows for weight decrease. Technician B says aluminum does not dissipate heat as well as steel or other heavier metals. Who is correct?
B only
Technician A says the rotor converts kinetic friction into static friction for stopping the vehicle. Technician B says the caliper assembly straddles the outside diameter of the rotor. Who is correct?
B only
The normal operation of a dual-piston master cylinder is being discussed. Technician A says the secondary piston is moved by the pushrod. Technician B says the primary piston produces the pressure to move the secondary piston. Who is correct?
B only
Trailer brakes are being discussed. Technician A says that hydraulic surge brakes are typically used on RV units. Technician B says that electric trailer brakes are typically used on utility and RV units. Who is correct?
B only
Brake fade is being discussed. Technician A says a thin layer of gas between the pads or linings and the rotors could cause brake fading. Technician B says heat is the greatest cause of brake fade. Who is correct?
Both A and B
Brake friction materials are being discussed. Technician A says molding bits of metal into a brake lining produces an excellent friction material. Technician B says composite linings can be made from synthetic fibers bonded together. Who is correct?
Both A and B
Brake lamp bulb replacement is being discussed. Technician A says some taillamp and stop lamp bulbs can be replaced without removing the lens assembly. Technician B says on some vehicles, the complete taillamp lens assembly must be removed for access to the bulbs. Who is correct?
Both A and B
Electrohydraulic brakes are being discussed. Technician A says an electrohydraulic brake system controls hydraulic braking action through the use of electrical solenoids. Technician B says the system shares information with ABS, TCS, and electronic suspension. Who is correct?
Both A and B
Pushrod adjustment is being discussed. Technician A says a loss of braking power can result if the pushrod adjustment is too short. Technician B says a low brake pedal can result if the pushrod adjustment is too short. Who is correct?
Both A and B
Technician A hydraulic fluid can transmit motion and force because a fluid cannot be compressed. Technician B says mechanical advantage in a hydraulic system is proportional to the size of the input piston versus the output piston. Who is correct?
Both A and B
Technician A says a rotor that is refinished too thin will not have proper heat transfer capabilities and should be replaced. Technician B says one should not turn the rotor on one side of the vehicle without turning the rotor on the other side of the vehicle. Who is correct?
Both A and B
Technician A says air fills the rear chamber when brake application opens the air valve and closes the vacuum valve, and the front chamber is kept in vacuum. Technician B says when the brakes are held at midpoint, both valves are closed to trap vacuum and atmospheric pressure and keep the diaphragm in a balanced position. Who is correct?
Both A and B
Technician A says although four-wheel disc brakes have become standard equipment of most cars and light trucks, drum brakes continue to be in use for a few rear-wheel brakes. Technician B says no law or regulation requires disc brakes, but the brake performance requirements of FMVSS 105 make front disc brakes virtually mandatory. Who is correct?
Both A and B
Technician A says an inspection of the braking system should include the wheel assemblies. Technician B says a brake inspection includes components of the steering and suspension systems. Who is correct?
Both A and B
Technician A says both drums on an axle should be machined to the same diameter. Technician B says drum diameters must be within 0.005 inch of one another. Who is correct?
Both A and B
Technician A says brake pads are position in the caliper on the sides of the rotor. Technician B says it is possible to identify the friction material of a new brake pad by observing a printed code on the edge of the pad or shoe. Who is correct?
Both A and B
Technician A says brake tubing should be double flared or ISO flared. Technician B says an ISO tubing seat must be used with the ISO flare. Who is correct?
Both A and B
Technician A says disc brakes are more effective than drum brakes. Technician B says disc brakes require more application pressure than drum brakes. Who is correct?
Both A and B
Technician A says drum brake disadvantages include poorer heat dissipation and less fade resistance than disc brakes. Technician B says drum brake disadvantages include lack of self-adjustment without special linkage, and a greater tendency than disc brakes to pull and grab. Who is correct?
Both A and B
Technician A says duo-serve brakes only self-adjust in reverse. Technician B says only leading-trailing brakes will self-adjust as necessary going in either direction. Who is correct?
Both A and B
Technician A says electrical circuits have an electrical pressure (force) that is used to move electrons through a circuit. Technician B says a lack of resistance in an electrical device (load) will prevent work being performed to the extent it was designed. Who is correct?
Both A and B
Technician A says excellent refinishing results can be achieved with an on-vehicle lathe. Technician B says one advantage of an on-vehicle lathe is that the rotor does not have to be removed from the spindle or the hub. Who is correct?
Both A and B
Technician A says except for the master cylinder pushrod adjustment, vacuum and hydraulic power-assist units are not adjusted in normal service. Technician B says if the booster is suspect, it is removed with a new or rebuilt unit, or it can be rebuilt in the shop. Who is correct?
Both A and B
Technician A says improper toe on one rear wheel will create a thrust angle change in the rear axle. Technician B says setback can be the result of a collision. Who is correct?
Both A and B
Technician A says improper toe will feather wear the tread and may cause steering problems. Technician B says if the centerlines of the tires are equal, the wheels are toed out. Who is correct?
Both A and B
Technician A says it is not necessary to disconnect the brake hose from the caliper if the caliper is not being removed from the vehicle. Technician B says on some vehicles the brake pads can be removed from the caliper without removing the caliper from the vehicle. Who is correct?
Both A and B
Technician A says kinetic friction changes kinetic energy into thermal energy. Technician B says static friction holds the car in place when it is stopped. Who is correct?
Both A and B
Technician A says lever-type vacuum power-assist brake system gives the driver a "feel" for the braking effort. Technician B says this "feel" is similar to that of a nonpower boost brake system. Who is correct?
Both A and B
Technician A says lockup is a condition in which a wheel stops rotating and skids on the road surface. Technician B says that positive wheel spin happens with no traction and the wheel spins but does not move the vehicle. Who is correct?
Both A and B
Technician A says most late model vehicles are equipped with computer-controlled brake and stoplamp circuits. Technician B says on some vehicles the turn signal and brake lamp switches are inputs to a module that delivers power to the respective bulbs. Who is correct?
Both A and B
Technician A says new drums may be protected by a coating that must be thoroughly cleaned off the friction surfaces before installing the drums. Technician B says refinished drums contain metal particles that must be removed before installing the drums. Who is correct?
Both A and B
Technician A says on some vehicles the disc brake pads can be visually inspected without removing the calipers. Technician B says on some vehicles disc brake pad thickness can be measured without removing the calipers. Who is correct?
Both A and B
Technician A says that energy can be stored by a spring in an accumulator. Technician B says that energy can be stored by gas under pressure in an accumulator. Who is correct?
Both A and B
Technician A says that regardless of wear pattern, all of the pads on an axle should be replaced at the same time to prevent uneven braking and wear. Technician B says many manufacturers are now supplying brake pads of ceramic materials as the pad of choice. Who is correct?
Both A and B
Technician A says the air and vacuum valves used on a tandem diaphragm must control vacuum and atmospheric pressure on two diaphragms at the same time. Technician B says when the brakes on a tandem diaphragm system are released, there is a vacuum on both sides of each diaphragm. Who is correct?
Both A and B
Technician A says the energy used by the braking system is based on the kinetic energy, mass, weight, and speed of the vehicle and its braking system. Technician B says the amount of friction in a brake system depends on the pressure (force) exerted on the friction components and the surface area?
Both A and B
Technician A says the metering valve keeps the front disc brakes from operating until the rear drum brakes have started to work. Technician B says the proportioning valve reduces the hydraulic pressure at the rear drum brakes when high pressure is required at the front disc brakes. Who is correct?
Both A and B
Active braking systems require driver input to activate the braking of the vehicle.
False
All power boosters use hydraulic fluid pressure supplied by the power steering pump to assist in the application of the brakes.
False
Electronic braking systems cover all systems from antilock braking systems and traction control systems to the latest systems including vehicle stability systems.
True
Flexible brake hoses are needed to allow movement between the brake hydraulic components and the steering / suspension components.
True
Hydraulic brake system leaks can be internal and external.
True
Intake manifold vacuum decreases and increases as the engine is accelerated and decelerated.
True
Integral ABS systems combine the master cylinder, electric pump motor, and hydraulic modulator into one unit.
True
Loss of hydraulic power from the hydro-boost means the driver loses all braking ability.
True
Mechanical fade is usually a result of overheated drums.
True
Most caliper bodies have one or two large openings in the top of the casting through which the lining thickness can be inspected.
True
Power brakes are simply conventional brakes with an added power booster.
True
Semimetallic or organic compounds have different coefficients of friction.
True