Report on types of brakes
Prepared By : Abdulrahman wagih Alhusiny
drum brakes
drum brake Operation : As the brake pedal is pressed, it compresses the fluid in the
master cylinder and allows the piston of the wheel cylinder to expand outward.As the brake
lining of the shoe touches the inner surface of the drum, friction is generated in between
the brake shoe and drum and stops the vehicle from moving.
drum brake Functions : The primary function of the drum brakes system in a car is to stop
the vehicle’s movement and keep it stationary. When the brake pedal is pressed, the brake
fluid activates the wheel cylinder, which in turn forces the brake shoes to press against the
inner surface of the brake drum, slowing down the movement of the car.
Types of Drum Brakes
1. Leading/trailing shoe-type drum brake
2. Duo servo type drum brake
3. Twin leading shoe type drum brake
Parts of Drum Brake
1. Drum brake
2. Braking plate
3. Brake shoe with pads
4. Wheel cylinders
5. Brake lever
6. Brake shoe holder
7. Return spring
8. Parking brake cable
9. Brake shoe adjuster
Advantage Disadvantages
• Drum brakes can provide more braking force than an • Excessive heating can happen due to heavy braking, which
equal diameter disc brake. then can cause the drum to distort, and thus cause
• Drum brakes last longer because drum brakes have vibration under braking.
increased friction contact area than a disc. • Under hard braking, the diameter of the drum increases
• Drum brakes are cheaper to manufacture than disc slightly due to thermal expansion, the driver must press
brakes. the brake pedal farther.
• Rear drum brakes generate lower heat. • Brake shoes can overheat to the point where they become
• Wheel cylinders are simpler to recondition than with disc glazed.
brake calipers. • Excessive brake drum heating can cause the brake fluid to
• Brake shoes can be remanufactured for future use. vapourise.
• Drums have slightly lower frequency of maintenance due• Grab is the opposite of fade: when the pad friction goes up,
to better corrosion resistance. the self-assisting nature of the brakes causes application
force to go up. If the pad friction is enough, the brake will
stay engaged due to self-application, even when the
external application force is released.
• Another disadvantage of drum brakes is their relative
complexity.
• Maintenance of drum brakes is more time-consuming,
compared to disc brakes.
drum brake Malfunctions
1- Scraping or Grinding Noise
Drum brakes comprise several components that work together to slow your car down.
When a brake shoe’s friction material wears out, the backing plate will come into contact
with the brake drum. Every time you apply the brakes, it makes a grinding noise.
2- Low Brake Pedal
A low brake pedal might be an indication that the brake shoe and drum are too far apart. It
might also be the result of a leaking master cylinder or brake fluid.
3- Poor Braking Performance
When you press the brake pedal, if your car doesn’t stop or slow down right away, there
may be a problem with the brake shoe or drum. However, in vehicles with front disc brakes
and rear drum brakes, brake system problems may also be caused by a worn-out brake pad.
4- Soft or Spongy Brake Pedal
Your brake pedal may feel spongy due to cracked brake drums or air in the brake line. A
leaking brake line, however, might also be the cause. Brake fluid leakage can be caused by
brake lines because of their steel tubing, which is susceptible to rust and small holes.
disc brake Operation
disc brake Operation: In a disc brake, the brake pads squeeze the rotor instead of the
wheel, and the force is transmitted hydraulically instead of through a cable. Friction
between the pads and the disc slows the disc down.A moving car has a certain amount of
kinetic energy, and the brakes have to remove this energy from the car in order to stop it.
disc brake Functions : The primary function of the drum brakes system in a car is to stop
the vehicle’s movement and keep it stationary.
disc brake Type
1. Opposed Piston Type Disc Brakes
2. Floating Type Disc Brakes
Advantages Disadvantages
1. It is lighter than drum brakes. 1. It is costlier than drum brakes.
2. It has better cooling ( because the 2. Higher pedal pressure is required for
braking surface is directly exposed to the stopping the vehicle. This brake system is
air) installed with vacuum booster.
3. It offers better resistance to fade. 3. No servo action is present.
4. It provides uniform pressure 4. It is difficult to attach a suitable parking
distribution attachment.
5. Replacement of brake pads are easy.
6. By design they are self-adjusting
brakes.
disc brake Malfunctions
1. Noisy Brakes: This is one of the first symptoms commonly associated with bad brake rotors
2.
Vibrations from the Brakes: Excessive vibration or pulsation coming from the brakes is another
symptom of bad brake rotors
3. Grooves or Score Marks on the Rotor: These can be a sign of a bad or failing brake rotor
4. Increased Stopping Distances: This could be a sign of a problem with the brake rotor
5. Braking Failure: The main reason for the brake failure of the disc brake is insufficient braking torque.
There are two main factors that affect braking torque
a. Insufficient positive pressure output from the brake.
b. Reduced friction coefficient between brake shoes and brake discs
6. Brake Release Failure: This is another common type of disc brake malfunction
