Brake Mid Term
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
The cable that runs from the brake control mechanism to the equalizer is known as the rear cable.
False
Disc brake caliper internal components should be cleaned in:
denatured alcohol.
On a vacuum-boosted system, all of the following can cause poor power-assist unit operation EXCEPT:
excessive manifold vacuum.
Technician A says some rear disc brakes have a small parking brake drum built into the center of the rotor. Technician B says some rear disc brakes move the caliper piston to apply the parking brake. Who is correct?
Both
In a sealed hydraulic system, brake fluid is pressurized to:
all of the above.
Trailer brakes do not apply when the vehicle is moving in a _____ direction.
reverse
A vehicle equipped with a vacuum brake booster has no power-assisted stops with the engine off but operates normally with the engine running. Which of the following is the most likely cause?
A leaking check valve
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
Impact wrenches are being discussed. Technician A says they are most suitable for removing fasteners like wheel lug nuts or axle nuts. Technician B says most sockets are suitable for use with an impact wrench. Who is correct?
A only
Line and hose fittings are being discussed. Technician A says always use a flare-nut (line) wrench to loosen a line fitting. Technician B says an open-end wrench is sufficient for fully tightening the fittings. 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 that the most common use of a dial indicator is to measure the runout in a disc brake rotor. Technician B says that feeler gauges are used to measure disc brake rotor runout. Who is correct?
A only
Technician A says the hydraulic tubing used in the brake system is double-wall, welded-steel tube. Technician B says brake tubing is coated with a tin- or lead-based alloy to reduce vibration. Who is correct?
A only
Technician A says the weight of a car is not distributed evenly on all four wheels even when the vehicle is standing still. Technician B says front brake systems are smaller than rear units. Who is correct?
A only
What type of mechanism keeps the parking brakes levers in the applied position?
A ratchet and pawl
Brake linings are:
All the above
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
Technician A says that to remove a parking brake control mechanism, the parking brake should be fully applied before raising the vehicle. Technician B says that to remove parking brake control components, relieve parking brake cable tension by backing off the adjusting nut from the brake cable equalizer. 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 the procedure-indicated illustration is a method of seating new pads. Technician B says the procedure shown is a method of retracting the caliper piston. 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
Proportioning valves are being discussed. Technician A says inertia and momentum cause weight to shift forward during braking. Technician B says the weight shift is proportional to the braking force and rate of deceleration. Who is correct?
Both
Technician A says a low fluid level in the reservoir may indicate worn brake pads. Technician B says a small geyser of brake fluid from only one master cylinder reservoir chamber when the brake pedal is applied may indicate abnormal cup wear. Who is correct?
Both
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
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
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
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
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
Technician A says metering valves function only during the initial stages of braking. Technician B says the proportioning valve restricts fluid to the rear wheels, thereby lowering the pressure to help prevent wheel lockup in the rear. Who is correct?
Both
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
Technician A says the brake warning light will remain on with the ignition switch in the RUN position if the parking brake is partially applied. Technician B says a low brake fluid level in the master cylinder may cause the brake warning light to come on. Who is correct?
Both
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. Who is correct?
Both
Technician A says the rotor hub contains the wheel bearing assembly. Technician B says the bearings on the nondriving wheels of many vehicles are tapered roller type bearings. Who is correct?
Both
Technician A says the setup shown in the following figure is being used to check drum internal diameter. Technician B says the setup shown in the following figure is being used to check for an out-of-round drum. Who is correct?
Both
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
Technician A says to adjust the service brakes before adjusting the parking brake. Technician B says to clean the threads of the adjusting nut before adjusting the parking brake. Who is correct?
Both
What provides the friction surfaces necessary for stopping the wheel?
Drum and shoes
The primary brake shoe is sometimes called the trailing shoe.
False
All of the following may cause the red brake warning light to illuminate EXCEPT:
Fuel low
Brake hose diameter is usually specified as the ____ diameter of the hose.
Inside
Technician A says grabbing brakes may be caused by worn rotors or pads. Technician B says pedal pulsation when the brakes are applied is caused by grease or brake fluid contamination of the pads. Who is correct?
Neither
Technician A says the parking brake shown should be adjusted with the parking brake applied. Technician B says each wheel cable must be adjusted separately. Who is correct?
Neither
Technician A says the tool shown is used to adjust the booster's vacuum valve. Technician B says the tool is used to set the depth of the booster's diaphragm. Who is correct?
Neither
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
Disc brakes require higher operating pressure than drum brakes.
T
Intake manifold vacuum decreases and increases as the engine is accelerated and decelerated.
T
Power brakes are simply conventional brakes with an added power booster.
T
Some brake drums are finned to help them dissipate heat more efficiently.
T
The clamping action of frictional material in the rotating disc or rotor creates heat.
T
The rotor has a machined braking surface on each side.
T
_____ braking systems apply the trailer brakes in case the trailer disconnects from the tow vehicle.
Trailer Breakaway
The tool shown in the illustration is used to:
extend the rear caliper piston.
The item indicated by the letter A is used to:
indicate pad wear.
DOT 5 brake fluids may be mixed with or used to replace DOT ____ brake fluids.
none of the above
