Automobile brakes are usually made according to the construction method are always classified into two


1. Drum brakes,
2. Disc brakes


 
However, the disc brakes work by slowing down the wheel to keep it from spinning.

DRUM BRAKES

The action of the disc brake is to hold the drum, which is rotating with the wheel, with the help of the brake shoes.
Drum brakes based on performance
1. External contracting type
2. Internal expanding type is divided into two types.

EXTERNAL CONTRACTING TYPE

 



On the outside of the wheel or on the outside of the drum with the friction surface attached to the shaft attached to the wheel, the brake band applied from the drum to the drum presses the brake pedal closer to the drum and stops the rotation of the drum on the friction surface. These types of brakes are not commonly used in vehicles.

INTERNAL EXPANDING TYPE

This is the most common type of braking system used in vehicles.

The brake drum is built as a hub at the end of the axle shaft. The axle casing also has a back plate. The brake shoe, anchor and expander are mounted on a back plate made of pressed steel.
The back plate is also called the torque plate (this is because it receives the torque reaction that occurs when the brakes are applied).


CONSTRUCTION
A pair of shoes, attached to the back plate. The brake shoe is provided with frictional linings. The brake shoes are retracted from the brake drum using retractor springs.


WORKING
One end of the brake shoe is fixed to the back plate so that the force applied to the brake pedal is felt at the next end. (Expander or cam) This force acts against the force exerted by the shoe and moves away from each other, rubbing the friction linings of the shoe inside the rotating brake drum and trying to hold the drum by the friction force felt against the drum's hand.
The force exerted between the brake shoes is applied to the brake shoes by any Brake Actuating Mechanism.
An adjuster is also provided between the shoes to adjust the brakes according to the wear of the shoes.

BRAKE SHOE
The brake drum is held in place by the force of friction, and braking is made possible by the action of the brake shoes.
Two types of brake shoes are used in automobiles.

1. Leading Shoe
2. Trailing Shoe
The lead shoe tries to stick to the shoe according to the rotation of the drum.


But the shoe tries to move away from the drum according to the rotation of the drum in the trailing shoe.
The force felt on the leading shoe when the brake is applied will be greater than the force felt on the trailing shoe.


If you have a leading shoe and a trailing shoe, you will experience different strengths in both shoes when the brakes are applied. As more force is applied to the leading shoe there is more heat and break fading occurs.
To overcome this the floating expander type drum brake or floating anchor type drum brake is used.


The braking system used by the two leading shoes allows the vehicle to stop very quickly due to the increased force exerted on the drum, but in reverse gear these two shoes work similarly to the trailing type and are not suitable for very early use as they generate more heat while operating.
In a system that uses two trailing shoes, the force exerted by the shoes on the brake drum will be less. So the driver has to put more force on the brake pedal. Such adjustments can be made to servo brakes or power brakes.
Vehicles often use drums that include a leading shoe and a trailing shoe.