How Brake Boosters Work

Your car’s braking system is made up of countless components, with the brake booster being one of the most important. Simply put, the brake booster’s job is to make it easier for you to apply the brakes by essentially multiplying the force exerted on the brake pedal. There are a couple of different types of boosters out there, but the one you’ll most commonly find is the vacuum-type brake booster.

Figure 1: Your brake booster is mounted to the engine bay firewall with the brake master cylinder bolted to it.

Now, what exactly is the brake booster and how does it work? You’ll find your brake booster here, mounted to the engine bay firewall with the brake master cylinder bolted to it. On the vacuum-type brake booster, you’ll find a vacuum connection on the face of the canister. If you cut away the canister, inside you’ll find a rubber diaphragm that separates the chamber in two, a rubber diaphragm, return spring, an air valve, and a push-rod that passes through the booster and connects to the brake pedal.

Figure 2: Inside the brake booster's canister, you'll find a rubber diaphragm that separates the chamber in two, a rubber diaphragm, return spring, an air valve, and a push-rod that passes through the booster and connects to the brake pedal.

A vacuum-type brake booster works by utilising the engine’s vacuum system via this connection, the booster amplifies the pressure of the brake pedal on the brake master cylinder, and in turn, the brakes themselves.

When the brake pedal is applied, the push rod that passes through the master cylinder opens up the air valve within the brake booster. This allows air to enter the rear-facing side of the diaphragm within the booster, increasing pressure on that side. This forces the push-rod even further into the piston within the master cylinder. As you apply more and more brakes, more air enters the booster’s rear chamber, multiplying the effect even further. Once you let off the brakes, the return spring resets the diaphragm back to its original position.

Figure 3: As you apply more and more brakes, more air enters the booster’s rear chamber, multiplying the effect even further.

Your brake booster makes a world of difference when it comes to the braking performance of your vehicle. By multiplying the amount of force applied to the brake pedal, it allows you to brake more readily and effectively, which can be the difference-maker in an emergency braking situation. Without a brake booster, the amount of force you would need to apply to your brakes would be enormous – the same way steering a car without power steering can be a pain. So, it goes a long way in enhancing not only the safety but also the overall comfort of your driving experience.

Figure 4: Without a brake booster, the amount of force you would need to apply to your brakes would be enormous.

Fitting an upgraded Brake Booster to your 4WD is one of the easiest, most effective upgrades you can perform, and Bendix now offers the perfect solution with the Bendix Ultimate 4WD Brake Booster Upgrade. Designed to be ADR compliant as well as a direct-bolt-in replacement for original equipment brake boosters, fitting the Bendix Ultimate 4WD Brake Booster increases braking performance by up to 30% and is an absolute must-have for any 4WD towing or carrying heavy loads.

Figure 5: Bendix now offers the Bendix Ultimate 4WD Brake Booster Upgrade.

Most OEM brake boosters are single-diaphragm, whilst the Bendix Ultimate 4WD Brake Booster boasts Dual-Diaphragm construction. Dual rubber diaphragms within the brake booster work to effectively double the diaphragm surface area without increasing the canister size of the brake booster, as well as increasing the vacuum pressure within the booster. This means increased braking effectiveness whilst still allowing the Bendix Ultimate 4WD Brake Booster to be a bolt-in replacement for the factory-fitted Brake Booster.

Thanks to its direct-bolt-in design, fitting the Bendix Ultimate 4WD Brake Booster is a simple matter of removing the factory-fitted brake booster, and slotting the Bendix Brake Booster upgrade in its place, needing no further modification to get the job done. Combine that with the Bendix Ultimate 4WD Brake Upgrade Kit and you have the recipe for unmatched 4WD braking performance.

Figure 6: Combine the Bendix Ultimate 4WD Brake Booster Upgrade with the Bendix Ultimate 4WD Brake Upgrade Kit and you have the recipe for unmatched 4WD braking performance.

For more Brake technical information or to see the range of 4WD upgrade brake boosters from Bendix visit our website at the link below.

To find your nearest Bendix stockist, click HERE.