TypesTypes

Parking BrakeService Brake

HydraulicDisc BrakesDrum BrakesDual System

Antilock Brake System (ABS)

Parking BrakeService Brake

HydraulicDisc BrakesDrum BrakesDual System

Antilock Brake System (ABS)

Play Principles of Braking

Play Principles of Braking

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Brake System Principles

Brake System Principles

Kinetic Energy

Mass Weight Speed Inertia and Momentum

Kinetic Energy

Mass Weight Speed Inertia and Momentum

Coefficient of Friction VideoCoefficient of Friction Video

Parking BrakeParking Brake

Not an “Emergency” Brake Used specifically to keep a parked vehicle from moving

Usually on rear wheels only Mechanically operated

Static Friction: at rest friction- More friction

Kinetic Friction: in motion friction- less friction

Not an “Emergency” Brake Used specifically to keep a parked vehicle from moving

Usually on rear wheels only Mechanically operated

Static Friction: at rest friction- More friction

Kinetic Friction: in motion friction- less friction

Typical Parking BrakeTypical Parking Brake

Play Parking Break Video

Play Parking Break Video

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Play Parking Brake Adjustment Video

Play Parking Brake Adjustment Video

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Service BrakesService Brakes

Primary Braking System Should be stronger than the engine

Hydraulic Operated Can be Vacuum, Hydro or Motor assisted

Disc System Drum System Dual System

Primary Braking System Should be stronger than the engine

Hydraulic Operated Can be Vacuum, Hydro or Motor assisted

Disc System Drum System Dual System

Typical SystemTypical System

Hydraulic PrinciplesHydraulic Principles

Fluids cannot be compressed Fluids can transmit Movement

Acts “Like a steel rod” in a closed container

Master cylinder transmits fluid to wheel cylinder or caliper piston bore.

Fluids can transmit and increase force

Force

Fluids cannot be compressed Fluids can transmit Movement

Acts “Like a steel rod” in a closed container

Master cylinder transmits fluid to wheel cylinder or caliper piston bore.

Fluids can transmit and increase force

Force

AreaPressure

HydraulicsHydraulicsSimplified Hydraulic Brake System

Drum BrakeMaster CylinderDisk Brake

Simplified Hydraulic Brake System

Drum BrakeMaster CylinderDisk Brake

Hydraulic pressure is distributed equally in

all directions

Hydraulic pressure is distributed equally in

all directions

Same line pressure to Same line pressure to all wheelsall wheels

Same line pressure to Same line pressure to all wheelsall wheels

The Hydraulic pressure is The Hydraulic pressure is the same, but the applied the same, but the applied force can be changed by force can be changed by

thethe piston size piston size

The Hydraulic pressure is The Hydraulic pressure is the same, but the applied the same, but the applied force can be changed by force can be changed by

thethe piston size piston size

The applied The applied pressure can pressure can be raised or be raised or lowered by lowered by piston sizepiston size

The applied The applied pressure can pressure can be raised or be raised or lowered by lowered by piston sizepiston size

Play Hydraulic Pressure VideoPlay Hydraulic Pressure Video

Brake Pedal DesignAdvantage by LeverageBrake Pedal DesignAdvantage by Leverage

First Mechanical Advantage is Driver’s foot

Length of Lever determines force applied

Uses Fulcrum Pedal Ratio

First Mechanical Advantage is Driver’s foot

Length of Lever determines force applied

Uses Fulcrum Pedal Ratio10

25:1 2.5 inches

50.5 inch

Play Break Pedal Leverage VideoPlay Break Pedal Leverage Video

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System BasicsSystem BasicsHydraulic actuation allows multiplication of pedal force.

In this system, a 10lb force on the pedal produces 360 lbs of force at the friction surface.

Hydraulic actuation allows multiplication of pedal force.

In this system, a 10lb force on the pedal produces 360 lbs of force at the friction surface.

Play Break Lines & Hose Video

Play Break Lines & Hose Video

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Brake FluidBrake Fluid

Properties of Brake FluidDoes not thicken or then with changing heat

Must not boilMust be compatible with brake parts material

Must lubricate internal partsMust not evaporate easily

Properties of Brake FluidDoes not thicken or then with changing heat

Must not boilMust be compatible with brake parts material

Must lubricate internal partsMust not evaporate easily

Brake Fluid typesBrake Fluid types

DOT 3 and 4- Polyglycol based

Most common Compatible with one another

Inexpensive Destroys paint Ruined by moister

DOT 3 and 4- Polyglycol based

Most common Compatible with one another

Inexpensive Destroys paint Ruined by moister

DOT= Department of TransportationHigh #= High stands, quality and boiling point

• DOT 5- • Silicone Based• Used only for heavy

duty applications

• Not Compatible with 4&5

• Very Expensive• Does not damage

paint

• DOT 5- • Silicone Based• Used only for heavy

duty applications

• Not Compatible with 4&5

• Very Expensive• Does not damage

paint

Fluid ContaminatesFluid Contaminates

Moister- Lowers boiling point water boils @ 212*F DOT 3 boils @ 401*F

Petroleum Based Product- soften rubber parts causing swelling

Dirt & Debris- causes corrosion and clogs

Air and Vapors- Compressible prevents pressure from reaching brakes

Moister- Lowers boiling point water boils @ 212*F DOT 3 boils @ 401*F

Petroleum Based Product- soften rubber parts causing swelling

Dirt & Debris- causes corrosion and clogs

Air and Vapors- Compressible prevents pressure from reaching brakes

Play Break Fluid VideoPlay Break Fluid Video

Master CylinderMaster Cylinder

Provides a reservoir for brake fluid and contains the driving pistons in the hydraulic circuit

2 TypesFront - Rear split -One piston for front brakes and one for rear-If a leak occurs you could lose front brakes

Diagonally split -One piston drives one front wheel and one rear wheel-Diagonal layout allows you to maintain directional control if a leak occurs

Provides a reservoir for brake fluid and contains the driving pistons in the hydraulic circuit

2 TypesFront - Rear split -One piston for front brakes and one for rear-If a leak occurs you could lose front brakes

Diagonally split -One piston drives one front wheel and one rear wheel-Diagonal layout allows you to maintain directional control if a leak occurs

Play Tandem Master Cylinder Video

Play Tandem Master Cylinder Video

Play Divide System Video

Play Divide System Video

Power Booster in closed positionPower Booster in closed position

Play Power Booster Video

Play Power Booster Video

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Drum BrakesDrum Brakes Expanding shoes create force on the inner surface of the drum

Used on the rear of some trucks and SUV’s

Self-energizing design requires less activation force

Require periodic adjustment

Expanding shoes create force on the inner surface of the drum

Used on the rear of some trucks and SUV’s

Self-energizing design requires less activation force

Require periodic adjustment

Drum Brake SystemDrum Brake System

Vented RotorsVented Rotors

Vented Rotors have Fins in the spaces between their machined surfaces. These spaces allow air to pass through, which helps carry heat away.

Nonvented RotorNonvented RotorNon Vented Rotors are used on smaller vehicles, and have no cooling fins

Play Brake Disc VideoPlay Brake Disc Video

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Disc Brake Caliper Assembly

Disc Brake Caliper Assembly

Caliper TypesCaliper TypesThere are 2 types of CalipersFixed

Calipers are disc brakes that use a caliper that is FIXED in position and does not slide. They have pistons on both sides of the disc. There may be 2 or 4 pistons per caliper

Floating Much more common Single Piston Easier to work with On “inboard” side of caliper

There are 2 types of CalipersFixed

Calipers are disc brakes that use a caliper that is FIXED in position and does not slide. They have pistons on both sides of the disc. There may be 2 or 4 pistons per caliper

Floating Much more common Single Piston Easier to work with On “inboard” side of caliper

Fixed CaliperFixed Caliper

•Motorcycles and some import trucks and cars use this type

•Similar to bicycle brakes

Sliding CaliperSliding Caliper

Applies pressure to two pads on opposite sides of rotor

Caliper Sliding Fixed

Friction Material exposed to air

Applies pressure to two pads on opposite sides of rotor

Caliper Sliding Fixed

Friction Material exposed to air

Fixed CaliperFixed Caliper

Applies two pistons to opposite sides of rotor

Caliper stays stationary

Disc Brakes require higher hydraulic pressure

Applies two pistons to opposite sides of rotor

Caliper stays stationary

Disc Brakes require higher hydraulic pressure

Play Disc Brake Calipers VideoPlay Disc Brake Calipers Video

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DiagnosisDiagnosis

Several different types of Complaints

Noise

Pulsation

Pedal travel

More later…

Brake NoiseBrake Noise

Wear Indicator

Brake PulsationBrake Pulsation

Usually a warped Rotor

Rotor needs trued on a brake lathe

Pedal TravelPedal Travel

NO BRAKES!!!!

•Excessive pedal travel

•Pedal feels soft and squishy

•Requires excessive effort to stop vehicle or my cause brakes to not function at all

Play Drum Brake Inspection VideoPlay Drum Brake Inspection Video

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Play Disc Brake Inspection VideoPlay Disc Brake Inspection Video

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Anti-Lock BrakesAnti-Lock Brakes A locked (sliding) wheel offers less braking force than a decelerating rolling wheel

The locked wheel also produces little lateral force, preventing steering control

Anti-Lock systems (ABS) monitor wheel lock-up and modulate brake pressure to provide controlled braking under most circumstances

A locked (sliding) wheel offers less braking force than a decelerating rolling wheel

The locked wheel also produces little lateral force, preventing steering control

Anti-Lock systems (ABS) monitor wheel lock-up and modulate brake pressure to provide controlled braking under most circumstances

Play ABS Principles Video

Play ABS Principles Video

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Anti-Lock BrakesAnti-Lock Brakes

System can have 2, 3 or 4 channels Trucks typically use 3 channel with only one sensor for the rear axle

Most modern cars use 4 channel system

Wheel speed sensors monitor each wheel speed

ABS controller and high-pressure pump increase or reduce pressure to wheels in order to maintain consistent wheel speeds

System can have 2, 3 or 4 channels Trucks typically use 3 channel with only one sensor for the rear axle

Most modern cars use 4 channel system

Wheel speed sensors monitor each wheel speed

ABS controller and high-pressure pump increase or reduce pressure to wheels in order to maintain consistent wheel speeds

Play ABS videoPlay ABS video

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Play Drum, Disc, & ABS Video

Play Drum, Disc, & ABS Video

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Other Braking SystemsOther Braking Systems

Air BrakesExhaust BrakesElectric or Trailer Brake

Air BrakesExhaust BrakesElectric or Trailer Brake

Play Disc Brake Replacement VideoPlay Disc Brake

Replacement Video

Play Replacing The Rotor VideoPlay Replacing The Rotor Video

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Play Drum Brake Replacement VideoPlay Drum Brake

Replacement Video

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