hydraulic brake quiz1 Flashcards
All the brakes drag on a truck equipped with hydraulic drum brakes.
The cause of this condition could be:
a seized metering valve.
insufficient brake pedal free travel.
a leaking primary cup seal in the master cylinder.
a pinched brake line to the rear brakes.
insufficient brake pedal free travel.
On a truck with hydraulic brakes a pulsating brake pedal could be caused by:
a rotor with excessive wear.
a drum worn bell mouthed.
a rotor with excessive parallelisim.
excessivly tight wheel bearings.
a rotor with excessive parallelisim.
When we say brake fluid is hygroscopic we mean that the brake fluid:
is water based.
must be mixed with water.
does not absorb water.
absorbs water.
absorbs water.
The first step to removing a brake caliper is to:
ensure the lid is secure on the master cylinder.
bleed the brakes.
remove the wheel bearings.
remove the rotor.
ensure the lid is secure on the master cylinder.
In the metric system, the joule is a measure of:
work
power
torque
force
work
The law of conservation of energy states:
energy disapates after being converted to heat.
energy can be transformed but not eliminated.
friction transforms energy to heat.
potential energy can be transformed to kinetic energy.
energy can be transformed but not eliminated.
Movement of heat through contact with another object is referred to as:
conduction
convection
radiation
expansion
conduction
The coefficient of friction may be defined as:
resistance to heat movement
how heavy the friction material is
the type of material being moved
resistance to movement between two objects
resistance to movement between two objects
Maximum braking occurs:
after the wheels are locked up
just before the shoes contact the drum
just before the wheels lock up with the brakes applied
after the wheels are locked up on dry pavement
just before the wheels lock up with the brakes applied
The brake fluid that will not mix with others is:
DOT 3
DOT 4
DOT 5
DOT 5.1
DOT 5
Self-energizing action may be described as:
When a brake shoe is drawn into the drum as it rotates
when a brake shoe forces the other away from the drum
when one shoe forces the other into the drum through a mecanical link
as the brake pad starts to engage with the rotor
When a brake shoe is drawn into the drum as it rotates
Internal brake parts should be lubricated with _______________ during assembly.
engine oil
soap and water
denatured alcohol
brake fluid
brake fluid
Before checking the lateral run-out on a rotor you should make sure that you:
tighten the wheel bearings
reduce toe-in to zero
remove the rotor
remove brake fluid from the master cylinder
tighten the wheel bearings
One precaution that should be observed before turning a drum on the lathe is to:
make sure the drum is not make of stainless steel.
make sure it is not past the minimum thickness.
make sure the damper band is installed.
allow .060 inch for machining.
make sure the damper band is installed.
A leaking secondary piston cup on the primary piston will allow:
brake fluid to leak from the drum brake circuit.
drum brakes to only partially apply.
brake fluid to leak into the fire wall.
no pressure from the drum brakes.
brake fluid to leak into the fire wall.
When the master cylinder is installed correctly, there should be a small clearance between the push rod and the primary piston. This clearance is to:
allow for heat expansion because of hard braking.
prevent brake drag.
reduce brake drag.
allow front brakes to apply first.
prevent brake drag.
The purpose of the compensating port in the master cylinder is to:
allow fluid to enter between the pistons in a dual master cylinder.
control release of hydraulic pressure when brakes release.
maintain a residual pressure in the brake system.
give more pressure for disc brakes.
control release of hydraulic pressure when brakes release.
When there is servo action taking place during braking, this is referring to:
the ablilty of one shoe to force the other shoe into the brake drum.
the action where the shoe is drawn into the drum by its rotation.
either of the above.
bothe of the above.
Correct Answer
the ablilty of one shoe to force the other shoe into the brake drum.
When prosportioning valves are used, their funciton is to:
provide a difference in pressure under all braking conditions.
provide a difference in pressure during light brake applications.
provide a difference in pressue under heavy braking conditions.
all of the above.
provide a difference in pressue under heavy braking conditions.
If a 0.5 cm diameter master cylinder is replaced with a 2.5 cm diameter master cylinder, the result would be:
more pressure in the system.
more force at the callipers.
less pressure in the system.
more force at the wheel cylinders.
less pressure in the system.
When a combination valve is used with front disc and rear drums the metering section is connected to the:
front brakes.
rear brakes.
between the front and rear brakes.
system before either front or rear circuits.
front brakes.
If a wheel cylinder does not have cup expanders then a _____________ must be used to prevent fluid leakage.
metering valve.
proportioning valve.
residual valve.
pressure differential valve.
residual valve.
Brake line must be flared using a(n):
ISO flare.
double flare.
single flare.
either a or b
double flare.
ISO flare.
When a combination valve is used in a hydraulic brake system it usually contains:
a pressure differential valve.
a metering valve.
a proportioning valve.
all of the above.
all of the above.
metering valves used in hydraulic brake systems are used to:
give different pressures in a brake system.
allow pressure to the rear brakes first.
are used in both the drum and disc circuits.
all of the above.
allow pressure to the rear brakes first.
The purpose of the residual check valve in a master cylinder is to:
release hydraulic pressure
keep some pressure on the disc brakes.
help seal wheel cylinders.
maintain a dual braking circuit.
help seal wheel cylinders.
The primary piston in a master cylinder is located:
at the front of the master cylinder.
in front of the compensating port.
piston closest to the firewall.
piston closest to the firewall.
One advantage of disc brakes in the ability to:
have a large degree of self-energization.
require less effort to apply.
wear very little when compared to drum brakes.
resist brake fade.
resist brake fade.
Which brake fluid should not be used with anti-lock brakes?
DOT 3
DOT 4
DOT 5
DOT 5.1
DOT 5
What would be the force applied by a wheel cylinder if 1000 kPa were applied to a piston that is 5 cm2 ?
500N
0.5N
50N
5000N
500N
Floating brake calipers are held in position by:
springs.
hydraulic pressure.
pins and guides.
bolt and key.
pins and guides.
When brakes are released after a brake application, the caliper piston is returned into its released position by:
the piston seal.
return springs.
hydraulic pressure.
all of the above.
he piston seal.
The principle of static friction is used in:
the service brake system with the vehicle in motion.
the park brake system.
ABS hydraulics.
the master cylinder system.
the park brake system.
Pressure in an enclosed liquid:
depends on the size of the container.
varies with the shape of the container.
acts with equal force on equal areas.
acts parallel to the surface.
acts with equal force on equal areas.
The force that tends to resist motion between objects in contact is called:
friction
pressure
clamp load
drag
friction
Friction between two sliding surfaces depends on:
the amount of force pressing the two surfaces together.
the temperature of the surfaces in contact.
the coefficient of friction of the materials in contact.
all of the above are correct.
all of the above are correct
The wheel cylinders and calipers convert pressure developed in the system into:
heat
mechanical force
directional pressure
static friction
mechanical force
What two methods are used to mount brake linings to brake shoes and brake pads?
bolts and machine screws.
bonding and riveting.
brazing and welding.
high temperature and high pressure.
bonding and riveting.
When inspecting brake rotors what do you measure for?
parallelism
lateral run out.
rotor thickness.
all the answers.
all the answers.
Grease or oil on rubber brake components has no negative effects on the brake system.
true
false
false
All brake master and wheel cylinders can be honed.
true
false
false
The diaphragm seal in the filler cap allows atmospheric pressure to act on the brake fluid without letting moisture in.
true
false
true
