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Reis Automotive

New Berlin 262-860-0030
Hales Corners 414-425-0077

Disc Brakes v. Drum Brakes

Vehicle Braking Systems – Disc or Drum

What’s the Difference between Disc Brakes and Drum Brakes?

When people think cars they often think of the freedom granted by powerful engines and high speeds – of passing a semi on the left side of a freshly-paved two-lane highway, cutting through some idyllic sun-soaked landscape.

But one of the most important features of a car is not how fast it can go – it’s how quickly it can stop.

While braking power isn’t the sexiest thing to consider about cars, it is easily the most important for safety. So what are the mechanical processes used to stop your automobile when the neighbor’s dog chases a ball into the street? It depends on which type of brakes your car uses. More than likely, your car has disc brakes (often called rotors) in the front, but the type of brake used on the rear axle could be either disc style or drum style. 

No matter the type of brake repair, Reis Automotive in New Berlin and Hales Corners has you covered — Set an appointment today!

Drum Brake Systems

Today’s cars, trucks, and SUVs get their braking power by using two types of mechanical brake systems. Since 1900, drum brakes in various configurations have been common for vehicle braking. Basically, a rotating drum spins in unison with the wheel and axle as the car travels; pressure is applied by to the inside of the drum through pads or shoes creating friction, slowing the car down.

Components of Drum Brakes

  • Back Plate – a non-rotating plate attached to the axle sleeve. Provides a durable and stable base on which to mount the components and hardware.
Drum Brake Base Plate New Berlin
  • Wheel Cylinder – a cylindrical structure containing pistons that apply outward pressure to brake shoes when hydraulic pressure from the master cylinder is applied.
  • Brake Shoes – crescent-shaped steel pieces lined on their outsides with materials containing high friction coefficients (commonly graphite, zinc, aluminum, lead, or brass held together with binding agents) to enhance friction when applied to the inside of the drum. (When braking force is applied to the outside of a drum, it is called a clasp brake)
Drum brakes and shoes
  • Brake Drum – connected to the spinning wheel and axle. Made from heat-conductive cast iron, resistant to wear, this structure provides the surface on which the brake shoes are applied.

 

Pros:

  • Less expensive than disc brakes
  • Allows for simple integration of a parking brake system

Cons:

  • Relatively poor heat dissipation
  • Trapped moisture in the drum may reduce friction and stopping power

 

Drum Brake Usage

Drum brakes were the go-to braking method for nearly half a century, starting when the Maybach car company installed the technology in one of their car models. The Renault Company later patented the invention. Only when Jaguar sent winning disc brake-equipped cars to the 1953 Le Mans did the tide begin turning toward the superior disc brake. Drum brakes remain in use today, but since most of the work is done by the front brakes, they are almost exclusively used as rear-braking systems or by heavy trucks.

 For the best brake repair services in Wisconsin, set an appointment at one of our two Reis Auto locations.

 

 Disc Brake Systems

Disc brakes use calipers to apply pressure to pistons. They transfer a pinching force via high-friction pads to a rotating disc attached to the wheel and axle. The disc brake system offers many advantages over drum styles – key among them is superior heat dissipation. The centrifugal force resulting from the rotating disc also sends moisture away from the braking surface.

Components of Disc Brakes

 
  • Calipers – houses brake cylinders, pistons, and pads. There are two types – fixed or floating:
    • Fixed – Stays stationary with both pads making contact with the disc at the same time
    • Floating – a single piston pushes the inner pad to the braking surface, which makes contact first and pulls the outside of the caliper and pad into contact with the disc
Mechanic Replacing Disc Brakes
  • Cylinder – houses hydraulic fluid to apply force to the pistons
Worn Brake Pad
  • Pistons – act on hydraulic forces within the cylinder to press the pads to the disc
  • Pads – produce friction when applied to the disc. Made from similar materials as brake shoes
New Disc Brake
  • Disc – the rotating surface on which friction is applied. Commonly made from grey iron

 

Pros:

  • Superior stopping power, remains proportional to pressure applied to the brake pedal
  • Components stay much cooler due to open air design
  • Wicks water away as it spins

Cons:

  • Wider disc circumference is needed to equal the braking power of smaller drum brakes
  • More difficult to incorporate parking brake systems into their design

 

Come to Reis Automotive for Disc or Drum Brake Repair and Replacement

Reis Automotive offers free brake inspections and full brake repair services. Whether you have squealing rotors or sticking rear brakes, come to our New Berlin or Hales Corners location for comprehensive auto brake maintenance.

Set an appointment with the brake repair professionals at Reis today!
New Berlin 17200 W Cleveland Ave. 262-860-0030
New Berlin MONDAY - FRIDAY 7AM - 5PM SATURDAY Closed
Hales Corners 5381 S 108th St. 414-425-0077
Hales Corners MONDAY - FRIDAY 7AM - 6PM SATURDAY 8AM - 2PM