Breaking Principles Lesson - clackamascareers.com Rubric ... creating more heat and more glazing. Unit 1: Introduction to Brake Systems Lesson 1: Fundamental Principles of Brake Systems

Breaking Principles Lesson

Performance Objectives:

1. Students will be able give examples of static and kinetic friction. 2. Students will be able to identify materials with high and low friction coefficient. 3. Students will have understanding of factors associated with the controlled stopping of a vehicle.

Standards:

11‐12.RST.7 Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., quantitative data, video, multimedia) in order to address a question or solve a problem.

11‐12.WHST.2 Write informative/explanatory texts, including the narration of historical events, scientific procedures/ experiments, or technical processes.

Assessment

Braking Principles Summary Writing Braking Principles Cornell Notes Summarization Rubric

Materials:

Braking Principles Power Point Presentation

Braking Principles Cornell Notes Worksheet

Braking Principles Summary Writing Summarization Rubric

Instructor: MacDonald/Christner/Sipp

Date:

Course Title: Automotive Service Technology Level 1 Specific Topic: Breaking Principles

Presentation Assignment: Fundamental Principles of Brake Systems

Procedure: Group: Hand out Cornell Notes worksheet. KWL discussion of what students already know about key points to engage prior knowledge. Complete interactive power point and have students complete Cornell notes worksheet. Individual: Hand out copies of Summarization Rubric. Students will complete Braking Principles Summary Writing. Group: Open discussion on Braking Principles. Finish KWL Chart

Application of Material:

Today was the introduction to brakes module. Students that have a better understanding of why brakes work are better prepared for brake labs.

Extension Questions:

Accommodations needed:

M d l 6Module 6:

Brakes

Module 6:Brakes

Brakes

Unit 1:Introduction toBrake SystemsBrake Systems

Lesson 1:Fundamental Principles

of Brake Systems

Effect of kinetic energy on the movement of Effect of kinetic energy on the movement of a vehicle

• The energy that moves a vehicle is called kinetic energy. A i hi l t i t th t d l t

Module 6:Brakes

A moving vehicle encounters resistance that depletes (takes away) its kinetic energy. Such resistance includes friction created by the vehicle’s tires rolling against the pavement and by the vehicle’s body moving thro gh the atmosphere ( ind resistance)Brakes

Unit 1:Introduction toBrake Systems

through the atmosphere (wind resistance).

• However, wind resistance and tire friction only slow a vehicle gradually. A modern brake system can bring a vehicle to an abrupt stop by rapidly converting aBrake Systems


of Brake Systems

vehicle to an abrupt stop by rapidly converting a vehicle’s kinetic energy into heat through the use of friction and then dissipating it.

The principles of friction involved in brake The principles of friction involved in brake action

• Friction is the resistance to movement that results from t bj t i bbi i t h th Th

Module 6:Brakes

two objects moving or rubbing against each other. There are two types of friction: kinetic and static.

Kinetic friction occurs between two objects, one of which is moving Kinetic friction always produces heat TheBrakes


is moving. Kinetic friction always produces heat. The more kinetic friction produced, the more heat produced. Automotive braking systems use kinetic friction to convert the energy of a moving vehicle into heat.

Brake Systems


of Brake Systems

Static friction occurs between two objects that are stationary. Automotive braking systems use static friction to hold a vehicle while it is parked. Static friction produces no heat.p


• Various factors that affect the amount of friction d d b t t bj t

Module 6:Brakes

produced between two objects

The rougher the surfaces of two objects, the more friction they produce.

Brakes


• Extremely rough surfaces create the most friction, but rough surfaces also wear down quickly. Therefore, automotive brakes use relatively smooth surfaces to avoid rapid wear. Brake Systems


of Brake Systems

p

• In order to compensate for their smooth surfaces, automotive brakes are applied with a great amount of pressure over a relatively large contact area.

The greater the pressure bringing the objects together, the more friction they produce. Therefore, the greater the pressure applied to the brakes, with all other factors

l th t th i t iequal, the greater their stopping power.


The greater the amount of shared contact area between t bj t th t th t f f i ti th bj t

Module 6:Brakes

two objects, the greater the amount of friction the objects produce.

• Automotive braking systems use the largest contact area possibleBrakes


area possible.

• The greater the contact area of a brake shoe or pad, the less heat the shoe or pad generates. Less heat allows for more friction, which makes the brakes Brake Systems


of Brake Systems

,more efficient.


NOTE: On drum brake systems, a brake shoe is applied to a brake drum to create friction On disc

Module 6:Brakes

applied to a brake drum to create friction. On disc brake systems, a brake pad is applied to a disc to create friction. Both of these systems are discussed later in this module.

Brakes


The hotter the friction surface of two objects, the less friction produced. (Rub your hands together and feel the heat!)

Brake Systems


of Brake Systems

• All heat that the brake system creates must dissipate as rapidly as it is created. The brake system can store little or no heat.

• Brake friction surfaces are made of a material that can conduct heat easily.

• Braking system components that produce friction (brake shoes or brake pads) are positioned so that(brake shoes or brake pads) are positioned so that air cools them. In some braking systems, forced air cools the components.


• The amount of friction that two objects produce when bbi i t h th i ll d th ffi i t f

Module 6:Brakes

rubbing against each other is called the coefficient of friction.

• An important brake friction surface is the brake lining that is mounted on either a brake shoe or brake padBrakes


that is mounted on either a brake shoe or brake pad. The brake lining produces friction by directly contacting another friction surface, either a brake drum or disc. The brake lining and the material that it touches must have the following special characteristicsBrake Systems


of Brake Systems

have the following special characteristics.

The brake drum or disc must conduct heat easily, hold its shape under extremely high heat, withstand rapid temperature changes, resist warping and distortion, and p g , p g ,wear well in general. Therefore, brake drums and discs are typically constructed of iron or steel combined with aluminum.


The brake lining must be somewhat softer than the brake d di At t t b k li i d f

Module 6:Brakes

drum or disc. At present, most brake linings are made of organic materials, metallic particles, and other minerals held together by a bonding agent.

NOTE: For years asbestos was commonly used inBrakes


NOTE: For years, asbestos was commonly used in brake linings. Because asbestos is a cancer-causing substance, federal law prohibits its use in brake systems.

Brake Systems


of Brake Systems

When the brake lining is applied to a drum or disc, it is important that the proper coefficient of friction is produced in order to ensure that the brakes are effective.

• If the friction coefficient is too great, the brakes may be “grabby” or overly sensitive. Overly sensitive brakes may cause the vehicle to skid too easily.


• If the friction coefficient is too low, brake application req ires e cessi e press re Appl ing the brakes

Module 6:Brakes

requires excessive pressure. Applying the brakes with excessive pressure creates excessive heat that could result in brake failure.

NOTE: Heat always reduces the coefficient of frictionBrakes


NOTE: Heat always reduces the coefficient of friction between two objects. Hence, high temperatures may cause brakes to fail.

• If the brakes create more heat than they can dissipate, Brake Systems


of Brake Systems

y p ,the friction coefficient reduces, which causes the brakes to fade.

Excessive heat also causes bonding agents in the lining to melt and flow to the surface, which produces a glaze on the shoe lining.

This glaze reduces the brake’s friction coefficient and causes more brake fadingcauses more brake fading.


Brake application then requires more pressure, thus ti h t d l i

Module 6:Brakes

creating more heat and more glazing.

Brakes

Unit 1:Introduction toBrake SystemsBrake Systems


of Brake Systems

How brakes are applied and how the How brakes are applied and how the hydraulic system functions

• Automotive brake systems fall into two major categories: i b k (h d li b k ) d ki b k

Module 6:Brakes

service brakes (hydraulic brakes) and parking brakes.

Service brakes stop the vehicle when it is in motion.

A parking brake holds the vehicle while it is parked. A Brakes


p g pparking brake is not designed to stop a moving vehicle.

NOTE: Parking brakes often use the same friction surfaces as service brakes.Brake Systems


of Brake Systems

• Hydraulic brake systems

In modern vehicles, hydraulic systems transfer pressure (which the driver applies)transfer pressure (which the driver applies) from the brake pedal to the brake shoes or pads. In some brake systems, servo action and/or power boosters enhance pressure from the driver’s pedal

Basic operationof brake system

from the driver s pedal.


Most vehicles use two separate hydraulic systems to ti t th b k th f f il f h d li

Module 6:Brakes

activate the brakes; therefore, failure of one hydraulic system does not result in complete brake loss.

• On some vehicles, one hydraulic system activates the front-wheel brakes whileBrakes


activates the front wheel brakes while the other hydraulic system activates the rear-wheel brakes.

O th t f hi l h d li

Front/rear split dual braking system

Brake Systems


of Brake Systems

• On other types of vehicles, one hydraulic system activates the brakes on one front wheel and one rear wheel while another hydraulic system activates the brakes on th th f t h l d h l I

Diagonal split dualthe other front wheel and rear wheel. In this design, the brakes on one hydraulic system are always at opposite corners of the vehicle.

g pbraking system


How the hydraulic braking system functions

Module 6:Brakes

• When the driver presses the brake pedal, hydraulic pressure builds in the master cylinder.

• Hydraulic pressure travels through the brake lines Brakes


y p gand valves to various brake activators — either the wheel cylinders or calipers.

• The wheel cylinders or calipers convert the hydraulic Brake Systems


of Brake Systems

pressure into mechanical force.

• In drum brake systems, hydraulic pressure causes a wheel cylinder to press the brake shoe against the brake drumbrake drum.

How brakes are applied and how the

• In disc brake systems, hydraulic pressure causes a caliper to press a brake pad against a rotating disc

How brakes are applied and how the hydraulic system functions

Module 6:Brakes

caliper to press a brake pad against a rotating disc. Therefore, in both systems, the action of one component pressing against another creates friction and slows the vehicle.

Brakes


NOTE: Wheel cylinders and calipers are discussed in more detail later in this module.

• When the brake releases, various devices move the Brake Systems


of Brake Systems

,brake shoes or brake pads away from the drums or discs.

NOTE: A cable or some other mechanical linkage — not the hydraulic system — activates the parking brake.

How brakes are applied and how the

• Regenerative braking

How brakes are applied and how the hydraulic system functions

Module 6:Brakes

Hybrid vehicles use the kinetic energy of the vehicle in motion to generate electricity. The electric motor(s) that are used to power the vehicle become electrical generators when the vehicle is decelerating.Brakes


when the vehicle is decelerating.

When the driver pushes the brake pedal, a signal is sent to the onboard computer(s), but instead of applying the hydraulic brakes, the electric motor(s) are used to slow the Brake Systems


of Brake Systems

vehicle. The wheels of the vehicle drive the electric motors, which generate electrical current that is sent to the hybrid storage battery and stored for later use to power the vehicle.

In emergencies or high-speed stops, the vehicle’s hydraulic brakes are used to slow the vehicle.

The components of the regenerative braking system include p g g ythe onboard computer(s) used to control the hybrid and brake systems, the hybrid electrical motor(s), the hybrid electrical circuits, and the hybrid storage battery.

Factors associated with controlled stopping Factors associated with controlled stopping of the vehicle

• Vehicle weight

Module 6:Brakes

The more weight a moving vehicle has, the more kinetic energy it possesses. Brake systems must convert kinetic energy into heat; therefore, any increase in vehicle weight puts more demand on the brakesBrakes


puts more demand on the brakes.

If a vehicle’s weight doubles, the amount of kinetic energy that the brakes must convert into heat doubles. The amount of heat energy resulting from the conversion alsoBrake Systems


of Brake Systems

amount of heat energy resulting from the conversion also doubles. Brakes on an overloaded vehicle may therefore become ineffective due to overheating.


• Vehicle speed

Module 6:Brakes

When the speed of a vehicle doubles, the brakes must convert four times the amount of kinetic energy into heat. Speed greatly increases the demand on a vehicle’s

Effect ofspeed on brakingBrakes


increases the demand on a vehicle s brakes.

A combination of high speed and excessive weight may push a vehicle’s brakes beyond their performance limit

speed on braking

Brake Systems


of Brake Systems

push a vehicle s brakes beyond their performance limit, resulting in a serious loss of stopping power.


• Friction between tire and road

Module 6:Brakes

The point where a vehicle’s tire contacts the road is called the tire footprint. Changes in the tire footprint affect a vehicle’s ability to stop. Below is a discussion of the factors affecting the tire footprintBrakes


factors affecting the tire footprint.

• The larger a tire’s diameter is, the larger its footprint is.

Brake Systems


of Brake Systems

The larger the tire footprint is, the more stopping power can be applied at the tire’s contact point with the road.

H i i i li h hHowever, it is important to realize that the greater a tire’s diameter is, the more braking power is needed to stop the vehicle.

NOTE: A general rule is that the larger a tire’s diameterNOTE: A general rule is that the larger a tire s diameter is, the more braking power is required.


• The greater the width of a tire is, the larger the tire f t i t i

Module 6:Brakes

footprint is.

The larger the tire footprint is, the more stopping power can be applied at the tire’s contact point with the roadBrakes


the road.

However, it is important to realize that the greater a tire’s width is, the more braking power is needed to stop the vehicle. Brake Systems


of Brake Systems

s op e e c e

NOTE: A general rule is that wide tires require large brakes.

• Excessive vehicle weight can distort tire tread and thereby reduce the tire’s hold on the road. Tires that cannot hold the road reduce the vehicle’s ability to stop.


• High vehicle speed can aerodynamically lift a vehicle it Thi lifti d th ti ’ h ld th

Module 6:Brakes

as it moves. This lifting reduces the tire’s hold on the road and reduces the vehicle’s ability to stop.

NOTE: Aerodynamic lift merely adds to the stopping problems that high speed creates Remember thatBrakes


problems that high speed creates. Remember that every time a vehicle’s speed doubles, the vehicle’s required stopping power quadruples, even if there is no aerodynamic lift.

Brake Systems


of Brake Systems

NOTE: To control the vehicle, friction must occur at the tire footprint. If this friction is lost, the vehicle is out of control.


• Tires grip the road more securely and can stop better if th h l i Th f th t i

Module 6:Brakes

if the wheels are moving. Therefore, the stopping power decreases if the brakes lock up the wheels.

Automotive engineers carefully avoid designing brake systems that are too powerful for the cars inBrakes


brake systems that are too powerful for the cars in which they are installed.

If a brake system locks up the wheels too easily, this significantly reduces stopping power and vehicleBrake Systems


of Brake Systems

significantly reduces stopping power and vehicle control.

Name________________________________ Period_______________________________

Cornell Notes Fundamental Principles of Brakes

Directions: As you listen and interact with the power point presentation, take notes on the topics listed in the key points section. You will use this information to construct a summary paragraph using only the information on this page.

Key Points Note-taking Column

Principles of Friction (Kinetic vs. Static)

__________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

Coefficient of Friction (High vs. Low)

__________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

How Brakes are Applied __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

Regenerative Braking __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

Factors Associated with Controlled Stopping of

the Vehicle

__________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________ __________________________________________________________________

Name:______________________________

Period: ____________________________

Writing Instructions:

Below write at least 3 complete sentences summarizing each of

the key points. (3 sentences for each key point for a total of at least 15 sentences.)

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

______________________________________________________________________________

6/27/12 1:19 PMiRubric: Automotive Safety Technology: SUMMARIZATION RUBRIC - U7A523: RCampus

Page 1 of 1file:///Users/sipps/Desktop/iRubric:%20Automotive%20Safety%20Tec…ogy:%20SUMMARIZATION%20RUBRIC%20-%20U7A523:%20RCampus.webarchive

Rubric: Automotive Safety Technology: SUMMARIZATION RUBRICUsing summary skills to evaluate reading comprehension.

Summarization Rubric

ATTEMPTED1 pts

NEEDS GUIDANCE2 pts

PROFICIENT3 pts

MASTERED4 pts

Succintness pts Student includesessential content—identifying keyconcepts andcondensing relevantsupporting informationto explain theconcepts.

ATTEMPTED

Generic details arelisted.

NEEDSGUIDANCE

Topic may beidentified, but not keyconcepts.Most supportinginformation is missing.Or studentindiscriminately listsinformation.

PROFICIENT

Most key concepts areidentified. Supportinginformation explainsthe concepts in abroad way.Demonstrates anability to generalizeinformation.

MASTERED

All key concepts areidentified. Supportinginformation creates anexact explanation ofthe concepts.Demonstrates anability to synthesizeinformation.

Organization pts Student organizesinformation from thereading selection in alogical format.

ATTEMPTED

No evidence oforganizationattempted.

NEEDSGUIDANCE

Organization israndom ordisconnected. There isnot an identifiableintroduction, body,and/or conclusion.

PROFICIENT

Organization isorderly. Sometransition words areused to connectinformation. There isindication of anintroductorystatement, body, andconcluding statement.

MASTERED

Organization is logical.Transitions smoothlylink each pointtogether.There is a clearlydevelopedintroduction, body,and conclusion.The source of theinformation isincluded.

Written Form pts Studentdemonstrates controlof the written form.

ATTEMPTED

Writing is illegible.

NEEDSGUIDANCE

Writing is unclear orsimplistic. Sentences are choppyor awkward.Convention errorsmake writing hard tounderstand.Word choice is simpleor not appropriate tothe subject. Subjectspecific vocabulary ismissing.Or student may copymuch of the contentfrom the readingselection.

PROFICIENT

Writing isunderstandable. Sentences arecomplete, but may bemechanical. Convention errors donot make writing hardto understand. Wordchoice is appropriateto the subject. Somesubject specificvocabulary appears inthe summary. Studentmostly uses his/herown words.

MASTERED

Writing is clear andexpressive. Sentencesconnect with a naturalflow/rhythm and arevaried in style.Fewconvention errorsoccur. Word choice isspecific and accurate.Subject specificvocabulary is appliedwith understanding.Student uses her/hisown words in a naturalway.

Build free rubrics at www.iRubric.com. Design, share, assess, collaborate. Rubric Code: U7A523

http://www.iRubric.com/

IntroductIon to AutomotIve technology

s 15

UNIT 2: safeTy

lessoN 1: ProTecTINg yoUrself aNd oThers IN The shoP

I. Responsibilityforsafety

A. Safetyintheautomotiveshopistheresponsibilityofeveryone.Safetymeansprotectingyourselfandothersfrominjuryatalltimes.Workingintheshoprequirestheuseofalargevarietyoftools,materials,andequipmentthatcaninjuretheworkerandothersintheshopifnotproperlyhandled.

B. Safetyintheshopincludestheitemslistedbelow.

1. Followingfederalguidelinesforsafepractices

2. Keepingtheshopfreeofhazards

3. Usingprotectiveclothingandequipment

4. Handlingandusingmaterialscontainingpotentiallyharmfulchemicalscorrectly

5. Usinghandtools,powertools,andequipmentcorrectly

6. FollowingweldingsafetyrulesII. Federalguidelinesforsafepractices

A. Twofederalagenciesissueguidelinesandoverseesafetyintheworkplace.

1. OSHA(OccupationalSafetyandHealthAdministration)issuesguidelinesconcerningsafetyfortheworker.

2. TheEPA(EnvironmentalProtectionAgency)issuesguidelinesconcerningsafetyfortheenvironment.

B. OSHAguidelinesandEPAguidelines

1. EachschoolwillhaveacopyofOSHAandEPAguidelinesthatmustbefollowed.DuetothechangingnatureofOSHAandEPAguidelines,theinstructorwillgoovercurrentguidelineswithstudents.AllstudentsarerequiredtofollowOSHAandEPAguidelines.

AutomotIve technology

S �6

2. OSHAguidelinesconcernthecorrectlabelingofhazardouscomponentsofequipment,thecorrectstorageofequipmentandmaterials,theuseofprotectiveclothingandequipment,theplacementofwarningandsafetysigns,andgeneralsafetypractices.

3. EPAguidelinesconcernproperhandling,storage,anddisposalofhazardousmaterials.Theycoveranymaterialsthatmaybehazardousifreleasedintotheenvironment,includingtheenvironmentoftheshop.

4. SeeLesson4formoreinformationabouttheseagencies. III. Generalshopsafetyrules

A. Duringthecourseofworkingintheshop,anautomotivetechnicianmovesfromoneareaoftheshoptoanother,movingpartsandequipmentaroundtheshopandperformingvariedtasks.Itisimportant that the shop floor be free of hazards that could cause technicianstosliportrip.

B. Inawidevarietyofshoptasks,wastematerialsareproducedthatcancausedangeroussituationsunlessthewastematerialsaredisposedoforstoredproperly.

C. Alwaysbesurethatshopexitsarewell-markedwithan“EXIT”signandareclearofobstructions.

D. Forpersonalsafetyandtohelpkeeptheshopfreeofhazards,alwayscomplywiththefollowingsafetyrules.

1. Workquietlyandfocussolelyonthejobathand.

2. Do not leave creepers laying on the floor. Always stand them againstthewall,wheelsoutward,whennotinuse.

3. Donotindulgeinhorseplayintheshop.Immatureandimproperbehaviorintheshopcancauseseriousaccidents.

4. Beforeperformingatask,considertherelevantsafetyprecautionsrelatedtothetaskandformulateapreventionplanforeachhazard.

5. Alwayswearprotectiveclothingandequipmentinanysituationwhereitisnecessary.


s 17

6. Wearprotectiveeyewearatalltimesintheshoparea.

NOTE:Thelawrequiresthatprotectiveeyewearbeavailableandwornincareerandtechnicaleducationcourseswherethereisareasonableprobabilityofinjury.

7. Donotwearrings,bracelets,watches,ornecklaceswhenworkingaroundmovingmachineryorelectricalequipment.

a. Jewelrycancatchinmovingmachinerywithseriousconsequences.

• Anecklacecanbecomeentangledinrunningmachinery,whichcouldpullthetechnicianintothemachineryandcausegreatbodilyharm.

• Ifaringorbraceletbecomesentangledorcaught,itcould result in a severed finger or serious injury to theheadorneck.

b. Ifaringorbraceletshouldaccidentallycreateashortcircuitofavehiclebattery,themetaloftheringorbraceletcouldbecomewhite-hotinaninstant,causingaseriousburn.

8. Donotputsharpobjectsintothepocketsofworkclothes.Theycouldcausepersonalinjuryordamagetoavehicle’sinterior.

9. Keephandsfreefromoilandgrease.

10. Wipe up grease and other spills from the shop floor immediately,oratleastputanoil-absorbingcompoundoverthem.

11. When cleaning up flammable liquids, always dispose of the rags in a metal container with a tight-fitting lid.


S �8

12. Donotlookinthedirectionofanotherpersonwhoiswelding.

13. Donotrunavehicleengineinsideaclosedgarageunlessthevehicleexhaustishookeduptoexhaustventilationequipment.Adeadlyamountofcarbonmonoxide,whichispresentintheexhaust,cancollectinaveryshorttime.

14. Donotsmokeintheshop,exceptinanareadesignatedforsmoking.

15. When pumping a flammable liquid from a large container into a small one, be sure to first attach a ground wire between both containers.

16. Alwaysbealertforhazardoussituationsintheshop.Promptlycorrectthem,ifpossible,andinformtheinstructorofthesituation.

17. Ifroadtestingavehicle,alwaysuseseatbelts,evenifonlygoingashortdistance.

18. Disconnectthebatteryasappropriate.Thiseliminateshazardsfromshortsthatcouldoccurduringrepairprocedures.

CAUTION: The vehicle manufacturer’s recommendations must be followed for disconnecting batteries. Some onboard vehicle computer systems can be damaged if the battery is incorrectly disconnected.

19. Whenpartsareremovedfromavehicle,theyshouldbestoredawayfromtheworkarea(onabenchor,iflargeparts,againstawall).


s 19

20. Asbestosparticlescancausecancer.Asbestosisfoundinbrakeshoesandclutches.Therefore,wearaparticlemaskwhendoinganycleaningworkonbrakeorclutchparts.Donotusecompressedairtocleanbrakeorclutchparts.

21. Donotlettheleadsontestingequipmentfallintothefanofavehiclewhiletheengineisrunning.Electricfanmotorscanturnonevenwiththeignitionoff.

22. Do not play with fire extinguishers. Use fire extinguishers only to extinguish fires.

23. Alwaysreadthelabelsonchemicalsandmaterialsandfollowtheinstructions.

IV. Generalsafetyrulesforhandlingtoolsandequipment

A. Donotoperateanypieceofequipmentunlesstrainedintheuseoftheequipment.

B. Evenifinstructedintheuseofapieceofequipment,donotuseitunless given specific permission by the instructor.

C. Selectthetoolorpieceofequipmentthatwillhandlethejobinthesafest and most efficient manner. Use tools or equipment only as recommendedbythemanufacturer.

D. Beforeusingatoolorpieceofequipment,inspectitfordefects,missingorimproperlyadjustedsafetyguards,andanyothermissingormalfunctioningparts.

E. Maintainandstoretoolsandequipmentproperly.Developaregularmaintenancescheduleforshopequipment.Discard,repair,orreplaceworntoolsbecauseworntoolscanbeasafetyhazardandadverselyaffectworkquality.

F. Donotusecompressedairtoblowdirtfromclothesanddonotpointacompressed-airhoseatanotherperson.

G. Whenusingcompressedairforcleaningobjectsintheshop,theairpressuremustnotbemorethan30poundspersquareinch(psi).

H. Keeptools,especiallytoolhandles,freefromoilandgrease.

I. Beforeusingatool,checkthehandletomakesureitissecure.Forexample,ahammerwithaloosehandleisunsafebecausetheheadmay fly off during use.


S 20

J. Whenoperatingelectrictools,usetheproperprecautionstoavoidelectricshock.

K. Beforeinspectingormakingadjustmentstopneumaticorelectrictools,alwaysdisconnectthemfromtheairorpowersupply.

V. Electricweldingsafety

A. Protectionfromelectricshock

1. Makesurethewelderisinstalledandhookedupproperly.

2. Donotuseequipmentthatisdamagedordefective,suchasanelectrodeholderwithdamagedinsulation.

3. Donotputtheelectrodeholderinwatertocoolit.

4. Do not use water to extinguish an electrical fire or any fire near thewelder.

5. Keeptheworkarea,equipment,andclothingdrywhenusingelectricweldersbecauseevenaslightamountofmoisturecanconductenoughelectricitytocauseasevereshock.

B. Protection from burns and fire

1. Make sure the work area is as fire resistant as possible.

2. Donotdragweldingcablesorhosesthroughdirtoroil,anddonotpullonacabletoforceitoveranobstruction.

3. Takeprecautionswhenhandlinghotworkpieces.Usetongsorpliers,nothands,topickuphotmetal.

4. Radiationfromaweldingarcisstrongenoughtosunburnorsometimesblisterbareskiniftheexposureisintenseorforanextendedperiod,sothearms,legs,andtorsoshouldbecoveredwith durable, flame-resistant clothing.

5. Keeptheworkareacleanandfreeoftrash,grease,oil,andotherflammable materials.

6. Keep a fire extinguisher, first-aid kit, and safety equipment withineasyreach.

7. Donotdrapeanelectricweldingcableoveranytypeofgascylinder,anddonotstrikeanarconagascylinder.


s �1

C. Protectionfromarcrays 1. Aweldingarcproducesultravioletandinfraredradiationthat

canseverelyburneyesthatareunprotectedwithapropershadeofprotectivelens.

NOTE: A welding hood or helmet protects the head from flying sparksandtheshadedlensprotectstheeyes.

2. Makesureallothersintheweldingareaarewearingeyeprotectionaswell.

3. Whenusingawelder,enclosetheweldingareatoprotectothersfromthedangersofarcrays.

D. Protectionfromtoxicfumesandvapors

1. Manyweldingactivitiesproducetoxicfumesandvaporsthatarehazardoustobreathe,andeveryworkstationshouldbeequippedwithaventilationorexhaustsystemcapableofsafelyremovingdangerousandirritatingsmokeandcontaminants.

CAUTION: Always position the head to the side of rising fumes.

2. In confined areas where the hazard of toxic fumes is increased, aweldershouldwearanair-suppliedrespiratororaself-contained breathing apparatus, not a filter-type mask that cannotcompensateforoxygendisplacement.

3. Cleanthemetalbeforewelding.Cleaningthemetalhelpsremoveanychemicalthatmightmixwiththefumesproducedbywelding.

VI. Oxyacetyleneweldingandcuttingsafety

A. Protection from burns (from heat or light rays), fire, and explosions

1. Donotallowoilorgreasetocomeincontactwithoxygenunderpressure.


S 22

NOTE: Nolubricationoftheapparatusisnecessary.

2. Donotuseoxygenasasubstituteforcompressedair.

3. Beforestartingtoweldorcut,makecertainthereisnoflammable material nearby.

4. Alwayswearweldinggogglesandheavygloveswhenworkingwithalightedtorch.

5. Wearweldinggogglesandprotectiveclothingthatblocksharmful light from the acetylene flame.

6. Whenusingawelder,enclosetheweldingareatoprotectothersfrom the dangers of acetylene flames.

7. Donotusematchesforlightingacetylenetorches.Asparklighter,heldatanangle,shouldbeusedtolightatorch.

8. Do not relight oxyacetylene flames on a hot work section in a small confined space.

CAUTION: Acetylene gas gathers in one spot.

9. Donotuseacetyleneatapressureabove15psi.

CAUTION: Using acetylene at a pressure above 15 psi may result in hand burns.

10. Useparticularcautionwhenweldingorcuttingindustyordirtylocations.

CAUTION: Dust can explode.

B. Protectionfromtoxicfumesandvapors

1. Manyweldingorcuttingactivitiesproducetoxicfumesandvaporsthatarehazardoustobreathe,andeveryworkstationshouldbeequippedwithaventilationorexhaustsystemcapableofsafelyremovingdangerousandirritatingsmokeandcontaminants.

CAUTION: Always position the head to the side of rising fumes.


s �3

2. In confined areas where the hazard of toxic fumes is increased, aweldershouldwearanair-suppliedrespiratororaself-contained breathing apparatus, not a filter-type mask that cannotcompensateforoxygendisplacement.

CAUTION: Argon is much heavier than air and quickly displaces oxygen, so be especially careful using the MIG process in a confined area, even though the area appears to have adequate ventilation.

3. Cleanthemetalbeforeweldingorcutting.Cleaningthemetal

helpsremoveanychemicalthatmightmixwiththefumesproducedbytheprocess.

4. Someofthematerialsthatgiveoffespeciallytoxicfumesarebrass,bronze,galvanizedmaterials,ironorsteelcoatedwithlead,orpaintcontaininglead.

C. Safehandlingofgascylinders

CAUTION: The acetylene and oxygen cylinders are highly pressurized and may explode if not handled properly.

1. Oxygenandacetylenecylindersmustbestoredinaventilatedareaandmustbekeptseparate.Allowatleast20ftbetweenoxygencylindersandacetylenecylinders.

2. Allgascylindersmustbesecuredinboththestorageareaand

onthewheeledcartwithasafetychainorapprovedlashing.

3. Theprotectivecapsmustbeinplaceanytimethecylindersarenotinuse.

4. Donotmovethecylinderswithoutprotectivecapsinplace.

5. Donotdroporknockcylindersaround.

6. Donottamperwithsafetydevicesormarkingsonacylinder.

7. Donotuseahammerorwrenchtoopenacylindervalve.

8. Do not move a cylinder unless confident in handling it.


S 24

9. Alwaysmoveagascylinderbyusingahandtruckwithasafetychainorbytiltingitslightlyandrollingitonitsbottomedgewithonehandontheprotectivecap.

CAUTION: Do not tilt the cylinder too far over center; it may cause the cylinder to drop.

VII. Liftingsafety

A. Thetechnicianwillencountermanysituationsinwhichheavyobjectsmust be lifted from the floor. Back injuries are common if lifting is notdoneproperly.

B. Alternativestoliftingheavyobjects

1. Avoidlifting,ifpossible.

2. Moveheavyobjectsbypushing,pulling,rolling,orsliding.

3. Usehoists,jacks,carts,andwheeltruckswhenpossible.

C. Toavoidinjurywhenliftingaheavyobject,useamechanicaldeviceorgettheassistanceofanotherperson.


s �5

D. Stepsofproceduretoliftanobject

CAUTION: Do not lift in an area where the floor is wet or greasy.

1. Spreadthefeetslightly,untilcomfortable,withonefootslightlyaheadoftheotherandalongsideoftheobject.

2. Bendtheknees,kneel,orsquat;donotbendtheback.

3. Useblockingunderobjectstogetahandhold.

4. Getagoodgripanduseglovesiftheobjecthassharporjaggedsurfaces.

5. Liftwiththeleg,arm,andshouldermuscles,straighteningthelegsandcomingtoastandingposition.

6. Shiftthefeettoturn;donottwist.

7. Lowertheloadbybendingtheknees,keepingthebackstraightand using leg and arm muscles, and keep fingers and toes clear ofobjects.

8. Use blocking to keep from pinching the fingers when setting the objectdown.

VIII.Personalprotectiveclothingandequipment

CAUTION: Personal protective clothing and equipment should not be considered the first line of defense against injury but rather as backup protection.


S 26

A. Wearprotectiveeyewearatalltimesintheshoparea.

NOTE:Thelawrequiresthatprotectiveeyewearbeavailableandwornincareerandtechnicaleducationcourseswherethereisareasonableprobabilityofinjury.

1. Specialsplash-resistantgogglesarewornwhenthereisapotentialchemicalhazard.

2. Whenwelding,aweldinghoodorhelmetmustbeworntoprotect the head from flying sparks and protect the eyes from burns.

3. Tintedgogglesmayberequiredifweldingisbeingperformedclosetotheworkarea.Consulttheinstructorfortheappropriatetintedgogglesfortheweldingoperation.

4. Properglassesandwiremeshgogglesorplasticspectacleswithsideshieldsarerequiredinimpacthazardareas,suchasgrindingareas.

5. Everyperson,includingvisitors,mustwearindustrial-qualityprotectiveeyewearatalltimesintheshoparea.


s �7

B. Wear a full face shield in situations where sharp flying objects could injuretheface.

C. Respiratoryprotectionissometimesnecessary.Respiratorydevicesconsistofameshthatcoversthenoseandmouth.Weararespiratorymaskwhendoingtasksthatcancreatedust.

D. Noiseintheshopcancausehearingdamage,dependingonthelevelandduration.Wearingearplugsandearmuffshelpsprotecttheearsfromnoisecreatedbyequipmentsuchaspneumatictools,grinders,andengines.

E. Adequatefootwearshouldbewornintheshoparea.Feetcaneasilybecrushed,cut,orpuncturedifnotproperlyprotected.

1. Footwearshouldhaveleatherorrubberoil-resistantsoles.

2. Footwearshouldprovideafullleatherorstrongfabriccoverfortheentirefootuptotheankles.

NOTE: Footwearwithsteel-reinforcedtoesprovidesevenmoreprotection.

3. High-topleatherbootsarerecommendedforweldingoperations.


S 28

F. Protectiveclothingforthebodyandhandsreducesthehazardofinjuryandprotectsstreetclothing.

1. Glovesandhandleathersareimportantpiecesofprotectiveclothing.Differenttasksrequiredifferentmaterials(e.g.,rubberglovesarewornwhenhandlingcausticchemicalsandheavyleathergloveswithgauntletsarewornwhenwelding).

CAUTION: If operating machinery and wearing gloves, the gloves may become entangled in the moving parts.

2. Apronsareusedtoprotectfromsparks,hotmetalsplashes,andsplashingliquids.Thematerialshouldbesuitablefortheintendeduse.

CAUTION: Never wear loose aprons around revolving or reciprocating machinery.

3. Coverallsprotectthebody.Overalls,avariationofcoveralls,donothavesleeves.Fire-resistantcoverallsmadeofcottonorwoolarerecommendedforweldingoperations.

4. Shopcoatsprovideprotectionagainstdirtandgreasethatsoilstreetclothing.Thesealsooffersomeprotectionagainstchemicalsandhotsubstances.

IX. Theimportanceofpropergroomingandhygiene A. Longhaircanbecomecaughtinmovingmachinery,whichcanresult

inaportionofscalpbeinglostorpulledintothemachinery.Keeplonghairoutofmachinerybypinningituporwearingacap.

B. Jewelryshouldnotbewornintheshop.SeesectionIIIinthislessonfor the specific hazards related to jewelry.

C. Havinggreasyhandscancauseslippagewhenworkingwithhandtools.Greasealsosoilsinteriorsandpaint.

D. Havinggreaseonworkshoescanspreadgreaseacrosstheshopfloor, which increases the risk of slipping and falling. Dirty, greasy coveralls/overalls and shoes can ruin vehicle interiors.

E. Having brake fluid and other chemicals on the hands could allow accidentaltransfertopaintedsurfacesandcauseexpensiverepairs.


s �9

F. Protective eyewear that is dirty and scratched is difficult to see through.Protectiveeyewearshouldbekeptclean.Donotplacethelenses down on the floor or table. The soft, plastic coating can easily bescratched.

X. Hazardousmaterialssafety

A. Fivegeneralsafetyrules

CAUTION: Consult the instructor before using an unfamiliar product.

1. Followthemanufacturer’srecommendations.Refertomaterialsafetydatasheets(MSDSs).SeeLesson4forinformationaboutMSDSs.

2. Carefullyreadtheproductlabelforcorrectusesandhazards.

3. Becarefultopreventspills,damagetothevehicle,orunsafesituations/conditions.

4. Properlystorechemicalsandusedrags. 5. Usechemicalsonlyfortheirintendedpurposes.

B. Hazardousmaterialsincludethefollowing:

NOTE: Thefollowinglistincludessomeofthemorecommonchemicalsfoundintheshopandisnotmeanttobeall-inclusive.SeeUnit3forthesafetyprecautionsandusesofthesechemicals.

1. Solventsandacids—Part-washingsolvents,chokeandcarburetorcleaner,brakecleaner,gasketremover,

digestive-typecarburetorcleaner,andvehiclebatteryacid

2. Lubricants—Rust-penetratingoil,siliconelubricant,liquidgraphite, motor oil, automatic transmission fluid, power steering fluid, gear lube, hydraulic fluids, various greases, and specialtyadditives(e.g.,oiltreatmentandgastreatment)

3. Gasesanddust—Gasesinengineexhaust,vaporsfromgasoline,refrigerantgas,andasbestosdustfrombrakeandclutchlinings


S �0

C. Safety from skin damage and fire

1. Manychemicalsintheshopposeahazardtotheskinandeyes.Followthesafetyprecautionsontheproductlabel.

2. Keepelectricaldevices,sparks,andanyhotmaterialawayfromflammable chemicals.

D. Safetyfromtoxicfumes

CAUTION: Breathing toxic fumes can cause dizziness, nausea, headaches, unconsciousness, and can even lead to death.

1. Acommonsourceoftoxicfumesintheshopistheexhaustfromarunningengine.Eachtimeavehicle’sengineisrunintheshop,exhaustventilationequipmentshouldbeattachedtothevehicletoproperlyventthecarbonmonoxide,apoisonousgasemittedintheexhaust.

CAUTION: Be sure to use approved exhaust ventilation equipment when operating a vehicle in an enclosed area.

2. Wheneverfumesorvaporsarepresent,besuretoturnontheshop’sventilationsystemassoonaspossibletoremovethem.


s 31

3. Usebreathingprotection,suchasarespirator,whenworkingwithanymaterialsorchemicalsthatcouldbehazardousifinhaled.

XI. Safetyprecautionsforsupplementalrestraintsystems(SRSs)and antilockbrakesystems(ABSs)

NOTE:Techniciansneedtobeawareofspecialsafetyconsiderationswhenworkingonoraroundthesesystems.

A. SRSorairbagsystem

1. Firstappearinginafew1985-modelvehicles,airbagsystemsarestandardequipmentonmostvehiclesontheroadtoday.Aruling by the National Highway Traffic Safety Administration requiredallnewpassengercarstohavedualairbags(oneonthedriver’ssideandoneonthepassenger’sside)by1998andallnewlighttruckstohavedualairbagsby1999.

2. The SRS is designed to inflate when a vehicle collides head-onwithanobjectataspeedofmorethan14mph.Duringthecollision,thedriverandpassengerimpacttheairbagratherthanthesteeringcolumnordashboard.

3. Inadditiontodriver-sideandpassenger-sideairbags,somevehiclesmaybeequippedwithside-impact,window,andrear-seatairbags.

4. Airbagsarerelativelynewdevices.Newsafetyissuesregardingairbagsarecontinuallybeingrecognizedandstudied.

5. Airbagsmustbeusedwithseatbelts,shoulderharnesses,andtheproperheadreststoprovidemaximumprotection.


S �2

NOTE:Itisimportantforeveryoneintheautomotiveindustry,includingautomotivetechnicians,toexplaintothepublicthattheSRSalonedoesnotprovidemaximumprotectioninacollision.

6. Beforeworkingnearavehicle’sairbags,besuretheyaredisabled.

CAUTION: The force of an air bag can break bones and cause other serious injuries.

7. Evenifanairbaghasbeendisabled,theairbagmaydeployifthediagnosticmodule’sreservepowerhasnotbeendepleted.

CAUTION: The diagnostic module keeps the air bag activated for some time after the negative battery cable has been disconnected. Wait until the diagnostic module’s reserve power has depleted before working on or around the SRS. The time can vary from a few seconds to over 30 minutes.

B. ABS

1. AnABShelpsthedrivermaintaincontrolofthevehiclewhenbraking.Ifthewheelslockduringbraking,thevehiclemayslideoutofcontrol.Theantilocksystempreventsthebrakesfrombeingappliedhardenoughtolockthewheels.

2. Evenwhentheantilocksystemclosesdown,normal power-assistedbrakingremains.Awarninglightlocatedinthe

instrumentpanelindicatesproblems.

3. ListedbelowaregeneralprecautionstoobservewhenservicingtheABS.

CAUTION: Failure to observe these precautions may result in personal injury and damage to the ABS.

a. Followtheserviceinformationcarefully.Usetheproperserviceinformationforthevehicle.Usingthewrongsequenceofservicesteps,skippingsteps,orusingthewronginformationleadstounnecessaryreplacementofparts.

b. Some brake parts contain asbestos fibers that can become airborneasdustduringbrakeservice.Followthelatestfederalprocedureswhenworkingwithasbestos.


s 33

CAUTION: Asbestos is a cancer-causing substance. Do not breathe asbestos dust or allow it to escape into the air.

c. ManycomponentsofanABSarenotserviceable;replacethemasanassembly.DisassemblinganABScomponentthatisnotdesignedtobeservicedmaycausepersonalinjuryorsystemmalfunction.

d. ThereisnoonebleedingprocedurethatappliestoallABSs.Proceduresvarygreatlyfromsystemtosystem.TobleedavehiclewithanABS,usethemanufacturer’sspecific bleeding method for the vehicle being serviced.

e. IfusingelectricarcweldingequipmentonavehiclewithanABS,disconnectthebatteryandpowertraincontrolmodule(PCM).

f. AnABSoperatesatveryhighpressures.AlwaysdepressurizetheaccumulatorbeforeservicingtheABS.

g. Toprotectthecontrolmodule,neverdisconnectorconnectanyABSconnectorwhiletheignitionswitchison.

h. PortionsofanABSoperateatverylowsystemvoltages;therefore,neveruseaconventional12-volttestlighttoprobecircuits.Aconventional12-volttestlightcandamagetheantilockcomponents.Alwaysuseahigh-impedancedigitalmultimeter(DMM)toprobethecircuits.

i. WhenworkingwithwiringonanABS,nevertouchtheelectricalconnectionsorpinsorallowthemtocontactthebrake fluid. This kind of contact damages the PCM.

j. Beforetestdrivingavehiclewithabrakeproblem,testthebrakesatalowspeedtobesurethatthecarstopsnormally.

C. ProceduresforidentifyingvehiclesequippedwithanSRSandABS

1. On some vehicles, the vehicle identification number (VIN) indicatesthatthevehicleisequippedwithanSRSandABS.Checkthemanufacturer’sserviceinformationtodeterminewhatdigitsindicatethatthevehicleisequippedwithanSRSandABS.


S �4

2. TheschematicsmayalsocomewithvariouswarningsthatthevehicleisequippedwithanSRSandABS.

3. SomevehicleshaveamarkonthesteeringwheelcovertoindicateanSRS.

3-2-1 Reading Guide Name: _________________

Text Title: Protecting Yourself and Others in the Shop

In complete sentences, write three things you learned from your reading: 1.______________________________________________________________________

________________________________________________________________________

2.______________________________________________________________________

________________________________________________________________________

3.______________________________________________________________________

________________________________________________________________________

In complete sentences, write two questions you have after reading this selection:

1.______________________________________________________________________

________________________________________________________________________

2.______________________________________________________________________

________________________________________________________________________

In one complete sentence, summarize what the text was about:

________________________________________________________________________

________________________________________________________________________

________________________________________________________________________

Six Vocabulary Words:

1.

2.

3.

4.

5.

6.

Sometimes I change it to what the “six most important words” in the article are for the

student and why (I always have to let them know that function words don’t count –the, a,

and—even if they do appear more often than concept words)

AS1-L1-U2

WORK SAFETY IN THE SHOP

Directions — Answer the following questions by writing all responses on this sheet. 1. Name the two federal agencies that issue safety guidelines for the workplace and describe

the focus of each agency. A. B. 2. Write the reason for each safety rule below. A. Do not wear jewelry in the shop. B. Do not run a vehicle engine inside a closed garage unless hooked up to exhaust

ventilation equipment. C. Wear a particle mask when doing cleaning work on brakes or clutch parts. D. Discard, repair, or replace worn tools. E. Do not use an electrode holder that has damaged insulation. F. Handle acetylene and oxygen cylinders with care.

3. Match the personal protective equipment (PPE) on the right that is most appropriate for the description on the left. All the PPE choices will not be used.

_____ A. Loud noise created by grinder _____ B. Handling of caustic chemicals _____ C. Street clothes could get soiled _____ D. Potential for breathing dust _____ E. Wear every day in the shop _____ F. Potential for chemicals splashing in eyes _____ G. Working around toxic fumes _____ H. Flying objects could injure the face

1. Air-supplied respirator 2. Apron 3. Ear muffs 4. Face shield 5. Leather gloves 6. Protective eyewear 7. Respiratory mask 8. Rubber gloves 9. Shop coat 10. Splash-resistant goggles 11. Tinted goggles

4. Why must the SRS be disabled before working on or around the air bags? 5. What can happen if an ABS component that is supposed to be replaced as an assembly is

disassembled?

Documents

Breaking Principles Lesson - clackamascareers.com Rubric ... creating more heat and more glazing. Unit 1: Introduction to Brake Systems Lesson 1: Fundamental Principles of Brake Systems