5/5/2005 MAE 442

Power Brake Booster

Team Needs An A

MAE 442 Final Presentation

5/5/2005 MAE 442 2

Brake Booster Assists the driver in

applying brake force by

amplifying the input

from the brake peddle.

Fourxdoctor.com

5/5/2005 MAE 442 3

Types of Brake Assist Hydro Power

Found on large trucks, mostly

diesels

Uses pressure from power

steering pump

Vacuum Assisted Found in SIE

Uses the engine vacuum to

assist

5/5/2005 MAE 442 4

Vacuum Booster Uses the vacuum from

the intake manifold or an additional pump

A valve allows atmospheric air to be let into the chamber

The vacuum pulls the diaphragm and pushes the primary piston

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Cut-Away of a Vacuum Booster

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Vacuum Booster Pros

Simpler operation

Works great with SIE

Cheaper system

More energy efficient

Does not decrease

engines Horsepower

Cons Large bulky

system

Must have

adequate vacuum

Can have leaks

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Hydro-Booster Uses the pressure from the power

steering pump

Activation of brake pedal increase

internal pressure

Booster output piston applies

pressure to the Master Cylinder

Nitrogen canister stores hydraulic

pressure to assist braking after

engine shuts down©bosch_usa

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Hydro Booster Pros

Better Power over

Vacuum

Long life span

Saves space

Less pedal travel and

greater braking force

Cons Can have leakage

High Stress on brake

lines

Expensive system

Must use power steering

or additional pump

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Basic Set up Schematic

©bosch_usa

5/5/2005 MAE 442 10

Typical Performance Curve Hydraulic boosters can

produce more than twice the force of a vacuum booster

Modern hydraulic boosters use a backup pump for safety

Hydro-max™ booster

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Our Hydro-Booster Display From Pump to

Boost(High Pressure)

From Boost to Pump

(Low Pressure Return)

From Boost to Steering System

(High Pressure)

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Pump

Hand Crank Pulley(used to turn pump) (usually connected to motor)

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Hydro Booster

Rod Pushes on

Master Cylinder

Connects to

Fire Wall Here Brake Pedal Pushes Rod

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Sources HydraTech Braking Systems

http://www.hydratechbraking.com Vanco Power Brake Supply

http://www.vancopbs.com HowStuffWorks.com

http://auto.howstuffworks.com Robert Bosch Corporation

http://www.boschusa.com SAE International

http://www.sae.org Fourxdoctor Off-Road Preparations

http://www.Fourxdoctor.com