What are the parts of the rear brake?

The rear brake consists of the wheel-end braking hardware (disc or drum), the actuation system (hydraulic lines, master cylinder, and proportioning/ABS components), and the parking brake mechanism (cables or electronic actuator). The exact parts depend on whether the vehicle uses rear disc or drum brakes and whether it has a mechanical or electronic parking brake; below is a clear breakdown for cars, motorcycles, and bicycles.

Rear disc brake (cars and many motorcycles)

Most modern cars and motorcycles use a rear disc brake, which clamps pads against a rotor. These assemblies may also integrate the parking brake either inside the rotor (drum-in-hat) or within the caliper via a lever or electric motor.

• Brake rotor (disc)
• Caliper body (floating or fixed) and caliper bracket
• Guide/slide pins and boots
• Inner and outer brake pads with shims
• Abutment clips/anti-rattle springs
• Piston(s) with seals and dust boots
• Bleeder screw
• Flexible brake hose and rigid hard line at the rear axle/trailing arm
• Backing/splash shield (where fitted)
• Pad wear sensor (acoustic tab or electronic sensor on some models)
• ABS tone ring (reluctor) and wheel speed sensor mounting nearby
• Parking brake mechanism:
  

  • Drum-in-hat parking brake: miniature brake shoes, return springs, hold-downs, and adjuster inside the rotor hat
  • Caliper-integrated parking brake: mechanical lever and screw mechanism or an electronic motor-on-caliper (EPB)
  • Parking brake cable or EPB wiring and connector

• Mounting bolts and pad pins/retainers

Taken together, these components provide clamping force on the rotor and incorporate noise reduction, heat management, and—if equipped—parking brake functionality and electronic sensing.

Rear drum brake (common on many economy cars and trucks)

Rear drum brakes expand brake shoes against the inside of a drum. They often double as the parking brake on vehicles that use drum rears or disc rears with a drum-in-hat parking section.

• Brake drum
• Backing plate
• Wheel cylinder (with pistons and dust boots)
• Primary and secondary brake shoes with friction linings
• Hold-down pins, cups, and springs
• Return springs
• Adjuster screw assembly (star wheel) and adjuster lever/cable
• Parking brake lever/strut on the trailing shoe
• Anchor pin and guide plates
• Flexible brake hose and hard line to wheel cylinder
• Backing plate dust shield (often integrated)

This configuration packages the service and parking brake functions compactly, relying on springs and an adjuster to maintain correct shoe-to-drum clearance as linings wear.

Shared hydraulic and control components (cars and motorcycles)

Whether disc or drum, rear brakes rely on upstream hydraulic and control hardware that manages pressure and balance, often with electronic assistance.

• Master cylinder and fluid reservoir
• Brake booster (vacuum or electro-hydraulic)
• Proportioning valve or electronic brake-force distribution (EBD)
• ABS/ESC hydraulic control unit (HCU) and pump/modulator
• Rigid brake lines and flexible hoses
• DOT brake fluid (DOT 3/4/5.1 for most cars/motorcycles; check spec)
• Wheel speed sensors and tone rings
• Load-sensing proportioning valve on some trucks/SUVs

These components set rear brake pressure, prevent wheel lockup, and integrate stability control, ensuring the rear system works in concert with the front brakes.

Parking brake systems (mechanical and electronic)

The rear parking brake holds the vehicle when stationary. It can be cable-operated or electronically controlled, depending on design and model year.

• Mechanical cable system:
  

  • Hand lever or foot pedal
  • Front cable, equalizer, and left/right rear cables
  • Levers at caliper or drum shoe linkage
  • Return springs and adjusters

• Electronic parking brake (EPB):
  

  • Motor-on-caliper actuators or centralized EPB module
  • EPB control unit and wiring
  • Console switch and status indicators
  • Integration with ABS/ESC for auto-hold functions

Regardless of actuation method, the parking brake interfaces with the rear wheel-end hardware to lock the wheels for secure parking and can integrate with driver-assist features on newer vehicles.

Bicycle rear brake components (if the question concerns bicycles)

Bicycles use either rim brakes or disc brakes at the rear, with parts tailored to mechanical cable or hydraulic systems.

Bicycle rear rim brake (V-brake/cantilever/road caliper)

Rim brakes squeeze pads onto the wheel rim via spring-loaded arms driven by a cable from the brake lever.

• Brake arms and mounting bolts/bosses (or caliper body on road bikes)
• Brake pads and holders
• Main cable and housing with ferrules
• Noodle and rubber boot (V-brake), or straddle cable/yoke (cantilever)
• Barrel adjuster at the lever or arm
• Centering/spring-tension screws
• Quick-release mechanism

This setup is light and simple, with easy pad replacement and on-the-fly adjustment via the barrel adjuster.

Bicycle rear disc brake

Disc brakes clamp pads against a rotor on the hub, controlled by either a hydraulic lever and hose or a mechanical cable.

• Rotor (6-bolt or Center Lock) and fixing bolts/lockring
• Caliper with pistons and pad-retention hardware
• Brake pads and spring
• Caliper adapter bracket (IS/Post/Flat mount as required)
• Hydraulic lever/master cylinder and hose with mineral oil or DOT fluid, or mechanical lever and inner wire cable
• Bleed ports, olives/barbs (hydraulic), or barrel adjusters (mechanical)
• Frame/fork mounts and rotor spacers/shims if needed

Bicycle disc systems offer stronger, all-weather braking and precise modulation, with maintenance centered on pad wear and hydraulic bleeding (if applicable).

Motorcycle rear brake components

Most motorcycles use a rear disc brake, controlled by a foot pedal and small master cylinder, with ABS common on newer models.

• Rear rotor (often solid or lightly vented)
• Single- or dual-piston caliper, bracket, and slide pins
• Brake pads, pad pin(s), and anti-rattle spring
• Rear master cylinder, pedal, and return spring
• Fluid reservoir (remote or integral)
• Braided or rubber brake hose
• Brake light switch (hydraulic or mechanical)
• ABS modulator and wheel speed sensor (if equipped)
• Parking/parking-lock devices on some scooters (varies by model)

The motorcycle rear brake complements the front brake, aiding stability and low-speed control; periodic pad and fluid service is essential for consistent performance.

How to identify what you have

A quick visual check and basic documentation can confirm your rear brake type and parts list before ordering components or starting service.

• Look through the wheel: a shiny flat disc indicates a rotor; a closed drum face suggests drum brakes.
• Parking brake feel: a cable-operated lever/pedal points to mechanical; a dashboard “P” switch indicates EPB.
• Check the owner’s manual or service manual for detailed schematics.
• Use your VIN or frame number on manufacturer parts catalogs to list exact components.

Confirming the brake type and parking brake arrangement ensures you source the correct pads/shoes, hardware, and service parts.

Summary

Rear brakes are built around either a disc or drum assembly at the wheel, supported by hydraulic and control components and a parking brake mechanism. Disc setups include a rotor, caliper, pads, slide hardware, and often an integrated or drum-in-hat parking brake; drums use shoes, springs, a wheel cylinder, and an adjuster inside a drum. Shared components include the master cylinder, lines, proportioning/ABS hardware, and—depending on the vehicle—mechanical cables or electronic parking brake actuators. Identifying your exact system ensures accurate parts selection and safe servicing.

What are the 5 parts of a drum brake system?

Drum Brake Components

• Backing Plate. The backing plate is one of the drum brake components in the form of a metal-based band which is relatively thin and is placed on the back of the drum brake system.
• Wheel Cylinders.
• Brake Shoes and Pads.
• Return Spring.
• Brake Shoe Holder.
• Brake Shoe Adjuster.
• Parking Brake Lever.
• Drum Brake.

What are the four major parts of a disc brake assembly?

The four major components of a disc brake assembly are the rotor, brake pads, caliper, and the hydraulic system that activates the caliper. The hydraulic system uses brake fluid to create pressure, which forces the brake pads to clamp onto the rotating rotor, creating friction to slow the vehicle.
 
Here is a more detailed description of each part:

• Brake Rotor (Disc): Opens in new tabA large, metal disc that is attached to the wheel hub and rotates with the wheel. When the brake pedal is pressed, the brake pads are pressed against this rotor to create friction and convert the car’s kinetic energy into heat. 
• Brake Pads: Opens in new tabThese are the friction materials that are pressed against the rotor to slow the vehicle. When the caliper’s pistons force them against the rotor, they create friction, which slows the car. 
• Caliper: Opens in new tabA housing that acts like a clamp, located at each wheel. It contains the brake pads and pistons. When brake fluid applies pressure, the pistons push the pads against the rotor to generate the braking force. 
• Hydraulic System (including brake fluid, lines, and master cylinder): Opens in new tabThis is the system that transmits force from the brake pedal to the calipers. When you press the brake pedal, the master cylinder pressurizes the brake fluid, which then travels through the brake lines to the calipers. This pressure is what activates the pistons in the caliper, causing the pads to squeeze the rotor. 

What are the six basic parts of a brake system?

The six basic parts of a hydraulic brake system are the Brake Pedal, Brake Booster, Master Cylinder, Brake Fluid, Brake Lines, and Wheel Brake Assemblies (which include calipers, pads, and rotors or drums, shoes). These components work together, using hydraulic pressure to convert the driver’s foot pressure on the pedal into frictional force that slows or stops the vehicle.
 
Here’s a breakdown of each part’s function:

1. Brake Pedal: The starting point of the system, it’s the pedal the driver presses to initiate braking. 
2. Brake Booster: This component uses vacuum to multiply the force applied by the driver’s foot on the brake pedal, making it easier to apply significant braking force. 
3. Master Cylinder: Often called the “heart” of the system, it converts the mechanical force from the pedal into hydraulic pressure. 
4. Brake Fluid: A hydraulic fluid stored in a reservoir, it transmits the pressurized force from the master cylinder to the wheel brakes. 
5. Brake Lines: These metal and rubber tubes carry the pressurized brake fluid from the master cylinder to the wheel brake assemblies. 
6. Wheel Brake Assemblies: This collective term includes:
   • Brake Calipers (for disc brakes): Clamps that hold the brake pads. 
   • Brake Pads (for disc brakes): Friction material that is squeezed against the rotor. 
   • Brake Rotors (for disc brakes): Metal discs attached to the wheel that slow down as the pads grip them. 
   • Brake Drums and Brake Shoes (for drum brakes): Found on some vehicles, where shoes press against the inside of a drum to create friction. 

What are the parts of the rear disc brake?

Disc Brake Components

• Brake Calipers. Brake calipers or calipers are an essential component in disc brakes in cars.
• Brake Shoes.
• Disc plate.
• Caliper Bracket.
• Piston Brake.
• Piston Seal.
• Master Cylinder.
• Reservoir Tank.