2. ๏จ Your driving a car or truck. You press on
the brake pedal, what happens?
๏ก A vehicle car goes through a process that
multiplies the force you apply to the brake
pedal with your foot and leg to stop the car.
๏ก This force is transmitted to the road through a
series of parts using fluid pressure in most of
todayโs vehicles.
3. ๏จ THE BRAKE PEDAL
๏ก There are two or three pedals in todayโs vehicles.
๏ก The pedal in the middle, or the pedal that is
immediately left of the gas pedal is the brake pedal.
๏ก The main purpose of the brake pedal is to multiply
the force that is exerted by the driver to slow and
stop the vehicle.
4. ๏จ BRAKE BOOSTER
๏ก Brake boosters are only used with power
braking systems. This is standard on todayโs
vehicles.
๏ก The booster is used to provide more braking
power while reducing the required effort
from the driver.
๏ก Boosterโs usually operate by using the
vacuum from the vehicle engine.
๏ก Not all vehicles have this type of booster.
Some provide assistance electrically.
๏ก Not all vehicles will have a booster. Some will
be direct pressure from the driver.
6. ๏จ MASTER CYLINDER
๏ก A master cylinder is
provided to convert force
from the booster into
hydraulic pressure.
๏บ If the vehicle does not
have a booster the
pressure is converted
from the brake pedal.
๏ก It is easier to transfer
hydraulic pressure than
mechanical pressure to
Figure 3
the brakes.
http://www.aa1car.com/library/brake_master_cylinder.gif
7. ๏จ BRAKE FLUID, LINES, AND HOSES
๏ก Fluid pressure travels from the master
cylinder through the brake lines to the brakes
at each wheel of the vehicle.
๏ก Brake lines are rigid except at the wheels
where it is necessary to provide flexibility
because of the movement of the suspension.
๏ก The rigid lines are either steel or a composite
material that can withstand the corrosive
environment under the vehicle.
๏ก Part of the line is steel while a short flexible
material (reinforced rubber) is used to connect
it to the moving parts.
8. ๏จ Brake fluid must withstand extreme
pressure and temperature changes. Itโs
VERY important that the fluid:
๏ก Cannot be compressed
๏ก Has a very high boiling point and flash point
๏ก Will not cause corrosion on the inside of brake
lines
๏ก Can withstand extreme cold without
thickening
10. ๏จ BRAKE CALIPERS
๏ก Fluid must be converted from hydraulic
pressure to mechanical pressure.
๏ก Calipers contain a piston/s that convert
hydraulic fluid pressure back to mechanical
pressure.
๏ก A bigger piston or multiple pistons will
produce more force.
๏บ Racing or high performance applications will
use 4 or even 6 pistons in the caliper.
๏ก Calipers are used with disk brake systems.
11. ๏จ BRAKE PADS
๏ก Brake pads are forced against the rotor by
pressure applied from the caliper.
๏ก Friction from the contact between the pad and
rotor slows the speed of the rotor.
๏ก This friction produces heat.
12. ๏จ BRAKE ROTORS
๏ก The rotor is acted upon by the brake pads.
๏ก The friction produced is converted into torque
at the wheel.
๏ก Rotors must be able to dissipate heat.
๏ก Many rotors are made with cooling fins that
help to quickly dissipate heat.
๏บ Rule of thumb โ the bigger the rotor is, the
better it is at reducing heat, the better the
stopping power of the brakes.
14. ๏จ WHEELS AND TIRES
๏ก The wheels and tires provide the contact
between the vehicle and the road.
๏ก The primary function is to provide traction.
๏ก Traction works three ways:
๏บ Increased acceleration.
๏บ Shortened stopping distance.
๏บ Increased cornering or handling.
16. ๏จ The brake system is designed to increase the
pressure you apply to the brake pedal.
๏จ The increased pressure is applied to the
calipers through hydraulics.
๏จ The calipers convert the hydraulic pressure
back to mechanical force against the rotors.
๏จ The rotors apply torque to the wheels.
๏จ The wheels and tires provide traction to stop
the vehicle.
17. ๏จ Erjavec, J (2010).Automotive Technology: A Systems
Approach. Clifton Park, NY: Delmar, Cengage
Learning. (p1424-1456)
Inline Citation -- (Erjavec, 2010)
18. 1. From autonest.org:
http://www.autonest.org/wp-
content/uploads/2011/08/TiresStopFeaturedImage.jpg
2. From seecharanautospares.com:
http://t0.gstatic.com/images?q=tbn:ANd9GcTC93pTwXrSYaFo
EjNwglWalDE8p83QqGmGhyjxN-0yZAZEB487
3. From aa1car.com:
http://www.aa1car.com/library/brake_master_cylinder.gif
4. From upload.wikimedia.org:
http://upload.wikimedia.org/wikipedia/commons/thumb/7/7
6/Hydraylic_disc_brake_diagram.jpg/619px-
Hydraylic_disc_brake_diagram.jpg
5. From truckinweb.com:
http://t1.gstatic.com/images?q=tbn:ANd9GcRD-
YK0vb_4ZOrSo2R_vkda2J9mAFy1LdlXZLzaotm8_o6QOvvuJg
6. From forums.tdiclub.com
http://t3.gstatic.com/images?q=tbn:ANd9GcQE5qr5y0F-
xlR5Jew6lFRqjjj1OIIKeiL6AImSn3GXldjLlHGd