Brakes Exam Questions All 100%
Correct Answers
On a car with disc/drum brakes, the front brakes grab quickly when light pedal pressure
is applied. This problem could be caused by a bad:
A. proportioning valve
B. pressure safety switch
C. metering valve
D. residual check valve - Answers -✔✔ C. The metering valve delays the flow of brake
fluid to the front calipers until the pressure in the system rises to a point where the
wheel cylinder can overcome the tension of the brake shoe return springs. The purpose
is to have both front and rear brakes apply simultane ously. This prevents the front
brakesfrom locking up during light brake applications.
The driver of a vehicle with power disc/drum brakes says that the brake pedal moves
slowly to the floor while maintaining pedal pressure at a stoplight. What could cause this
problem?
A. leaking primary piston cup in mast cylinder
B. leaking power brake booster
C. leaking residual check valve in master cylinder
D. internal leak in the combination valve - Answers -✔✔ A. If the primary piston cup in
the master cylinder is leaking pressure will not build up ahead of the primary piston to
increase pressure to the rear brakes. The piston will then move forward until the spring
is compressed enough to move the secondary piston. Consequently, this internal leak
will cause the brake pedal to slowly drop to the floor.
Which of the following would MOST LIKELY happen if the measurements taken from
the check shown above varied from the manufacture's specifications?
A. noisy brake operation
B. brake grab or pull
C. pulsating brake pedal
D. low brake pedal - Answers -✔✔ C. Poor rotor parallelism (thickness variation) will
cause a pulsating brake pedal. This is due to the caliper piston movement that occurs
as the pad rides over the alternating high and low areas on the disc. This action forces
brake fluid to flow back and forth from the caliper to the master cylinder, creating the
pulsating pedal feedback.
What is the purpose of the master cylinder residual check valve(s) on vehicles equipped
with drum brakes?
A. allows the driver to pump up the brakes
B. prevents air from entering the hydraulic system
C. prevents wheel lockup by reducing the hydraulic pressure
D. reduces pedal pulsation by controlling hydraulic pressure - Answers -✔✔ B.
Residual check valve(s) are used on drum brakes to keep residual low pressure (slight
,static pressure) in the brake system at all times even when the brake pedal Is released.
This pressure (5-20 psi) keeps the lips of the wheel cylinder piston cups tight against
the cylinder walls to prevent air from entering the system when at rest (brakes
released).
A tech has just overhauled the front brakes on a vehicle with front disc and rear drum
brakes. However, when he attaches a pressure bleeder (pressurized to about 25 psi) to
the master cylinder, he cannot get any fluid to come out of the disc brake caliper
bleeder screws. Which of the following is MOST LIKELY the cause?
A. bad proportioning valve
B. bad pressure differential valve
C. proportioning valve release button not activated
D. metering valve released button not activated - Answers -✔✔ D. A metering valve
requires a minimum pressure (typically between 75-125 psi) to open. At this point
pressurized fluid Hows to the front calipers. Since the bleeder tank is only pressurized
to 25 psi, fluid pressure is too low to open the metering valve during this procedure.
Therefore, when you use a pressure bleeder on a system with a metering valve, you
must manually keep the valve open by either pushing the button in on the end of the
valve, or pulling the stem outward on the end of the valve.
On a vehicle with single piston floating caliper front disc brakes, the brake pads on the
left side of the vehicle are almost completely worn while the right side is almost new.
Tech A says that too much rotor runout could be the cause. Tech B says that a binding
caliper piston could be the cause. Who is right?
A. Tech A
B. Tech B
C. Both
D. Neither - Answers -✔✔ B. Excessive rotor runout would cause a pulsating brake
pedal, but not uneven side-to-side pad wear. A frozen caliper piston on the other hand,
will keep both inner and outer brake pads equally applied against the rotor even when
the brake pedal is released. This constant friction will cause rapid pad wear in the
affected caliper as well as a front-end pull.
What is the purpose of the bar that is being removed from the brake assembly shown
below?
A. to equalize the braking force between the shoes during normal braking
B. to center the shoes after each brake application
C. to force the shoes into the drum when the parking brakes are applied
D. to reduce the distance between the shoes and the drum - Answers -✔✔ C. The
parking brake strut bar forces the brake shoes into the drum when the parking brake is
applied.
A hydraulic brake line is leaking. Which of the following is the correct repair procedure?
A. Cut out the bad section and replace the new steel tubing using compression fittings.
B. Replace the leaking line with double-flared, seamless copper tubing.
, C. Cut out the bad section and replace with single-flared steel tubing using flare nuts
and unions.
D. Replace the leaking line with double-flared steel tubing. - Answers -✔✔ D. Steel
tubing of the same size, type, and length with double flared ends must be used when
replacing a traditional SAE double inverted flare style hydrau lic brake line.
The set-up shown above is used to check:
A. rotor parallelism
B. wheel bearing adjustment
C. rotor lateral runout
D. rotor face wear - Answers -✔✔ C. Lateral runout is the move ment of the rotor from
side to side as it rotates on the steering knuckle spindle. The dial-indicator set-up shown
in the illustration is used to make this measurement once the wheel bear ing nut has
been tightened (bearing play removed).
Which of the following problems would be caused by using a residual check valve in a
disc brake master cylinder?
A. reduced brake pedal travel
B. reduced brake system pressure
C. increased brake pad wear
D. increased rotor runout - Answers -✔✔ C. If a residual check valve was installed in a
disc brake master cylinder, it would cause in-creased brake pad wear since the residual
brake pressure would cause the caliper pistons to keep the pads applied even when the
brake pedal is released.
A customer complains that their vehicle pulls to the right when the brakes are applied.
Tech A says a restricted brake line to the left caliper can cause this problem. Tech B
says a malfunctioning proportioning valve is probably the cause. Who is right?
A. Tech A
B. Tech B
C. Both
D. Neither - Answers -✔✔ A. A restriction in the brake line will cause a drop in fluid
pressure to the affected caliper. This will cause the caliper to be unable to exert the
same force against the pads as the unrestricted side. Because of this, the vehicle will
pull to the side where the pressure is highest and brake force is greatest. In this case,
that would be the right side.
With foot pressure applied, the brake pedal on a vehicle with vacuum assisted power
brakes moves down slightly when the engine is started. Tech A says that this condition
can be caused by a leaking power brake booster diaphragm. Tech B says that the
cause could be a faulty power brake booster check valve. Who is right?
A. Tech A
B. Tech B
C. Both
Correct Answers
On a car with disc/drum brakes, the front brakes grab quickly when light pedal pressure
is applied. This problem could be caused by a bad:
A. proportioning valve
B. pressure safety switch
C. metering valve
D. residual check valve - Answers -✔✔ C. The metering valve delays the flow of brake
fluid to the front calipers until the pressure in the system rises to a point where the
wheel cylinder can overcome the tension of the brake shoe return springs. The purpose
is to have both front and rear brakes apply simultane ously. This prevents the front
brakesfrom locking up during light brake applications.
The driver of a vehicle with power disc/drum brakes says that the brake pedal moves
slowly to the floor while maintaining pedal pressure at a stoplight. What could cause this
problem?
A. leaking primary piston cup in mast cylinder
B. leaking power brake booster
C. leaking residual check valve in master cylinder
D. internal leak in the combination valve - Answers -✔✔ A. If the primary piston cup in
the master cylinder is leaking pressure will not build up ahead of the primary piston to
increase pressure to the rear brakes. The piston will then move forward until the spring
is compressed enough to move the secondary piston. Consequently, this internal leak
will cause the brake pedal to slowly drop to the floor.
Which of the following would MOST LIKELY happen if the measurements taken from
the check shown above varied from the manufacture's specifications?
A. noisy brake operation
B. brake grab or pull
C. pulsating brake pedal
D. low brake pedal - Answers -✔✔ C. Poor rotor parallelism (thickness variation) will
cause a pulsating brake pedal. This is due to the caliper piston movement that occurs
as the pad rides over the alternating high and low areas on the disc. This action forces
brake fluid to flow back and forth from the caliper to the master cylinder, creating the
pulsating pedal feedback.
What is the purpose of the master cylinder residual check valve(s) on vehicles equipped
with drum brakes?
A. allows the driver to pump up the brakes
B. prevents air from entering the hydraulic system
C. prevents wheel lockup by reducing the hydraulic pressure
D. reduces pedal pulsation by controlling hydraulic pressure - Answers -✔✔ B.
Residual check valve(s) are used on drum brakes to keep residual low pressure (slight
,static pressure) in the brake system at all times even when the brake pedal Is released.
This pressure (5-20 psi) keeps the lips of the wheel cylinder piston cups tight against
the cylinder walls to prevent air from entering the system when at rest (brakes
released).
A tech has just overhauled the front brakes on a vehicle with front disc and rear drum
brakes. However, when he attaches a pressure bleeder (pressurized to about 25 psi) to
the master cylinder, he cannot get any fluid to come out of the disc brake caliper
bleeder screws. Which of the following is MOST LIKELY the cause?
A. bad proportioning valve
B. bad pressure differential valve
C. proportioning valve release button not activated
D. metering valve released button not activated - Answers -✔✔ D. A metering valve
requires a minimum pressure (typically between 75-125 psi) to open. At this point
pressurized fluid Hows to the front calipers. Since the bleeder tank is only pressurized
to 25 psi, fluid pressure is too low to open the metering valve during this procedure.
Therefore, when you use a pressure bleeder on a system with a metering valve, you
must manually keep the valve open by either pushing the button in on the end of the
valve, or pulling the stem outward on the end of the valve.
On a vehicle with single piston floating caliper front disc brakes, the brake pads on the
left side of the vehicle are almost completely worn while the right side is almost new.
Tech A says that too much rotor runout could be the cause. Tech B says that a binding
caliper piston could be the cause. Who is right?
A. Tech A
B. Tech B
C. Both
D. Neither - Answers -✔✔ B. Excessive rotor runout would cause a pulsating brake
pedal, but not uneven side-to-side pad wear. A frozen caliper piston on the other hand,
will keep both inner and outer brake pads equally applied against the rotor even when
the brake pedal is released. This constant friction will cause rapid pad wear in the
affected caliper as well as a front-end pull.
What is the purpose of the bar that is being removed from the brake assembly shown
below?
A. to equalize the braking force between the shoes during normal braking
B. to center the shoes after each brake application
C. to force the shoes into the drum when the parking brakes are applied
D. to reduce the distance between the shoes and the drum - Answers -✔✔ C. The
parking brake strut bar forces the brake shoes into the drum when the parking brake is
applied.
A hydraulic brake line is leaking. Which of the following is the correct repair procedure?
A. Cut out the bad section and replace the new steel tubing using compression fittings.
B. Replace the leaking line with double-flared, seamless copper tubing.
, C. Cut out the bad section and replace with single-flared steel tubing using flare nuts
and unions.
D. Replace the leaking line with double-flared steel tubing. - Answers -✔✔ D. Steel
tubing of the same size, type, and length with double flared ends must be used when
replacing a traditional SAE double inverted flare style hydrau lic brake line.
The set-up shown above is used to check:
A. rotor parallelism
B. wheel bearing adjustment
C. rotor lateral runout
D. rotor face wear - Answers -✔✔ C. Lateral runout is the move ment of the rotor from
side to side as it rotates on the steering knuckle spindle. The dial-indicator set-up shown
in the illustration is used to make this measurement once the wheel bear ing nut has
been tightened (bearing play removed).
Which of the following problems would be caused by using a residual check valve in a
disc brake master cylinder?
A. reduced brake pedal travel
B. reduced brake system pressure
C. increased brake pad wear
D. increased rotor runout - Answers -✔✔ C. If a residual check valve was installed in a
disc brake master cylinder, it would cause in-creased brake pad wear since the residual
brake pressure would cause the caliper pistons to keep the pads applied even when the
brake pedal is released.
A customer complains that their vehicle pulls to the right when the brakes are applied.
Tech A says a restricted brake line to the left caliper can cause this problem. Tech B
says a malfunctioning proportioning valve is probably the cause. Who is right?
A. Tech A
B. Tech B
C. Both
D. Neither - Answers -✔✔ A. A restriction in the brake line will cause a drop in fluid
pressure to the affected caliper. This will cause the caliper to be unable to exert the
same force against the pads as the unrestricted side. Because of this, the vehicle will
pull to the side where the pressure is highest and brake force is greatest. In this case,
that would be the right side.
With foot pressure applied, the brake pedal on a vehicle with vacuum assisted power
brakes moves down slightly when the engine is started. Tech A says that this condition
can be caused by a leaking power brake booster diaphragm. Tech B says that the
cause could be a faulty power brake booster check valve. Who is right?
A. Tech A
B. Tech B
C. Both
