Perform maintenance service check-up and repair to auto air-conditioning system

COMPETENCY BASED LEARNING MATERIAL

Sector: AUTOMOTIVE
Qualification: AUTOMOTIVE SERVICING NC III
Unit of Competency:

Perform Maintenance Service Check-up and Repair to Auto Air-
Conditioning System

Module Title:

PERFORM MAINTENANCE SERVICE CHECK-UP AND REPAIR TO
AUTO AIR-CONDITIONING SYSTEM

Technical Education and Skills Development Authority

East Service Road, South Superhighway, Taguig, Metro Manila

NATIONAL CERTIFICATE LEVEL 3

QUALIFICATION LEVEL

COMPETENCY-BASED LEARNING MATERIALS

No. Unit of Competency Module Title Code

1. Test and Repair Electrical • Testing and Repairing Electrical ALT 723316
Security System/ Security System/ Components
Components
• Identifying Electronic Engine ALT 723317A
2. Service Electronic Engine Management System Components ALT 723317B
Management
• Testing and Repairing Electronic ALT 723318
3. Overhaul Engine and Engine Management System ALT 723319A
Associated Components Components ALT 723319B
ALT 723319C
4. Service Automatic • Inspecting and Analyzing Engine
Transmission Failure ALT 723320

5. Perform Maintenance • Inspecting and Diagnosing ALT 723321
Service Check-Up and Automatic Transmission ALT 723322
Repair to AC System
• Pulling-out, Disassembling, and
6 Install Auto Air-conditioning Checking Automatic Transmission
System
• Assembling and Testing Automatic
7. Service and Repair Auto Transmission
Aircon Compressor and
Associated Components • Performing Maintenance
Service Check-Up and
Repair to Air-Conditioning
System

• Installing Auto Air-Conditioning
System

• Servicing and Repairing Auto
Aircon Compressor and
Associated Components

HOW TO USE THIS COMPETENCY BASED LEARNING MATERIAL

Welcome to the learning guide for the Module Performing Maintenance Service and Repair
to Auto Air-conditioning System. This learner’s guide contains training materials and
activities for you to complete.

The unit of competency "Perform Maintenance Service and Repair to Auto Air-conditioning
System" contains the knowledge, skills and attitudes required for an Automotive Service
Technician. It is one of the specialized modules at National Certificate level II (NC II).

You are required to go through a series of learning activities in order to complete each learning
outcomes of the module. In each learning outcome there are Information Sheets and
Resources Sheets (Reference Materials for further reading to help you better understand the
required activities. Follow these activities on your own and answer the self-check at the end of
each learning outcome. You may remove a blank answer sheet at the end of each module (or
get one from your facilitator/trainer) to write your answers for each self-check. If you have
questions, don’t hesitate to ask your facilitator for assistance.

Recognition of Prior Learning (RPL)

You may already have some or most of the knowledge and skills covered in this learner's guide
because you have:

• been working for some time
• already completed training in this area.

If you can demonstrate to your trainer that you are competent in a particular outcome, you don't
have to do the same training again.

If you feel you have some of the skills, talk to your trainer about having them formally
recognized. If you have a qualification or Certificate of Competence from previous training,
show it to you r trainer. If the skills you acquired are still current and relevant to the unit/s of
competency they may become part of the evidence you can present for RPL. If you are not sure
about the currency of your skills, discuss this with your trainer.

At the end of this learner’s guide is a learner’s diary. Use this diary to record important dates,
jobs undertaken and other workplace events that will assist you in providing further details to
your trainer or an assessor. A Record of Achievement is also provided for your trainer to
complete once you complete the module.

This module was prepared to help you achieve the required competency in performing
maintenance service and repair to auto aircon system. This will be the source of information for
you to acquire knowledge and skills in this particular trade, with minimum supervision or help
from your instructor. With the aid of these materials, you will acquire the competency
independently and at your own pace.

ƒ Talk to your trainer and agree on how you will both organize the Training of this unit.
Read through the learning guide carefully. It is divided into sections, which cover all the
skill, and knowledge you need to successfully complete in this module.

ƒ Work through all the information and complete the activities in each section. Read
information sheets and complete the self-check. Suggested references are included to
supplement the materials provided in this module.

ƒ Most probably your trainer will also be your supervisor or manager. He/she is there to
support you and show you the correct way to do thing. Ask for help.

ƒ Your trainer will tell you about the important things you need to consider when you are
completing activities and it is important that you listen and take notes.

ƒ You will be given plenty of opportunity to ask questions and practice on the job. Make
sure you practice your new skills during regular work shifts. This way you will improve
both your speed and memory and also your confidence.

ƒ Talk to more experience workmates and ask for their guidance.

ƒ Use the self-check questions at the end of each section to test your own progress.

ƒ When you are ready, ask your trainer to watch you perform the activities outline in the
learning guide.

ƒ As you work through the activities, ask for written feedback on your progress. Your
trainer keeps feedback/ pre-assessment reports for this reason. When you have
successfully completed each element, ask your trainer to mark on the reports that you
are ready for assessment.

ƒ When you have completed this module (or several modules), and feel confident that you
have had sufficient practice, your trainer will arrange an appointment with registered
assessor to assess you. The results of your assessment will be recorded in your
competency Achievement Record.

Inside this learner’s guide you will find the activities for you to complete and at the back are the
relevant information sheets for each learning outcome. Each learning outcome may have more
than one learning activities.

At the back of this learner’s guide is a Learner’s Diary. Use this diary to record important dates,
jobs undertaken and other workplace events that will assist you in providing further details to
your trainer or an assessor. A Record of Achievement is also provided for your trainer to
complete once you complete the module.

QUALIFICATION : AUTOMOTIVE SERVICING NC II

UNIT OF COMPETENCY : Perform Maintenance Service Check-Up and Repair of
Air-Conditioning System

MODULE : Performing Maintenance Servicing Check-Up and
Repairing Air-Conditioning System

INTRODUCTION :

This module contains information and practices in diagnosing air conditioning
system. It includes definite and clear instruction in diagnosing air conditioning system
components perform testing of possible cause and clear instruction techniques and
procedure in carry-out necessary repairs.

Summary Learning Outcomes:

At the end of this module you will able to:

1. Diagnose air conditioning system
2. Performed general check-up/service/repair and replacement of auto air

conditioning system components.

Assessment Criteria:

1. Diagnosing is in accordance with company standard operation procedure and
manufacturer specification.

2. Test is completed without causing damage to any workplace properly or
vehicle.

3. Correct information is accessed/interpret form the appropriate manufacturer
specification.

4. System performance is tested and the appropriate air-conditioning service
procedures are determined.

5. Correct information is recorded on the service slip.
6. Service of the system and component are carried out in accordance with

vehicle system manufacturer specification
7. Servicing is carried out according to industry regulations/guidelines, OH and S

procedure and the Philippine clean air act.
8. System is tested and results are recorded in accordance with company

policies and procedures.

Code No. Performing Maintenance Servicing, Check- Date: Developed Date: Revised Page # 1
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Pre-requisite

1. References:

1. Automotive Car Air Conditioning Manual, Toyota
2. Automotive Car Air Conditioning Manual, Nissan
3. Automotive Car Air Conditioning Manual, Citimotors
4. Automotive Car Air Conditioning Manual, Hyundai
5. Interpreting Automotive System, by: Harry G. Hill, pp 319 - 342

2. Equipment:

1. Recovery Machine
2. Vehicle with Air con
3. Complete set of Mock-up

3. Tools:
1. set of wrenches
2. set of screw drivers
3. set of pliers

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QUALIFICATION : AUTOMOTIVE SERVICE TECHNICIAN NC II

UNIT OF COMPETENCY : Perform Maintenance Service Check-Up and Repair of
Air-Conditioning System

MODULE : Performing Maintenance Servicing Check-Up and
Repairing Air-Conditioning System

LEARNING OUTCOME #1 : Diagnose air-conditioning system

ASSESSMENT CRITERIA:

1. Diagnosing is in accordance with company standard operation procedure and
manufacturer specification.

2. Test is completed without causing damage to any workplace properly or
vehicle.

3. Correct information is accessed/interpret form the appropriate manufacturer
specification.

4. System performance is tested and the appropriate air-conditioning service
procedures are determined.

5. Correct information is recorded on the service slip.

RESOURCES:

1. Automotive Car Air Conditioning Manual, Toyota
2. Automotive Car Air Conditioning Manual, Nissan
3. Automotive Car Air Conditioning Manual, Citimotors
4. Automotive Car Air Conditioning Manual, Hyundai
5. Interpreting Automotive System, by: Harry G. Hill, pp 319 - 342

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LEARNING EXPERIENCES / ACTIVITIES

LO# 1 – Diagnose air-conditioning system SPECIAL INSTRUCTIONS
LEARNING ACTIVITIES

- Can you explain the cycle of AC
system?

- Have you performed the charging
procedure according to the industry
standard?

- Were you able to repair and replace
component as required?

- How can you describe your experience
in performing the activities of the
previous module?

1.1.1 Evaluate AC system condition a. Read Auto Air conditioning system
• Function pages 319-342 by: Harry Hill
• Operation
• Location b. Answer self-check no. 1 after
answering, get the answer key from
a. Reading information/reference book your instructor and check your work
you may also surf then internet for honestly.
more information.

b. Accomplishing self-check

1.1.2 Describing and Identifying the AC
system components:
• Compressor
• Evaporator
• Condenser
• Expansion value
• Receiver drier

1.2.1 Handling AC system parts properly
and safety

1.3.1 Identify and Describing Tools and a. Reading information
Equipment needed b. Accomplishing self-check

1.3.2 Preparing the Tools and Equipment to a. Filling- up of borrower’s slip
be used

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1.4.1 Interpreting Specification of a. Reading repair manual
Diagnosing AC system based on the
repair manual

1.4.2 Testing/Checking/Repairing re- a. Checking/Repairing AC system
checking AC system

1.4.3 Filling-up of Inspection Checklist a. Recording result

1.4.4 Comparing

1.5.1 Identifying Defects of AC system a. Reading references on: Trouble
Diagnosing charts

1.5.2 Recording result in the inspection a. Diagnosing auto AC system
checklist

1.5.3 Recording result in the inspection a. Filing-up inspection checklist
checklist

1.5.4 Making report and recommendation

1.5.5 Remedies of Auto AC system
troubles

Congratulations: You have tried to
overcome the trouble if the Auto Air
Conditioning system. You are now ready to
perform the preceding activities. Keep up
the good work!

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SELF-CHECK LO#1

Diagnose, Check-up, Repair Auto AC System

DIRECTIONS: Choose: the best answer of the following and right only the letter provided
for before the number.

1. Which of the following is not part of an air-conditioning system?
a. Evaporator
b. Condenser
c. Radiator
d. Heater core

2. Which of the following can cause poor cooling temperature?
a. Loose pan belt
b. Expansion valve opening too large
c. Expansion valve opening too small
d. Dirty condenser

3. Which of the following causes air in refrigerating system
a. Discharge air in refrigerating system
b. Suction pressure abnormally high
c. Discharge pressure abnormally low
d. Suction pressure abnormally low

4. Which of the following causes expansion valve tends to clog heat-sensing tube
mounting defective.
a. Discharge pressure abnormally high
b. Suction pressure abnormally high
c. Discharge pressure abnormally low
d. Suction pressure abnormally low

5. Which of the following act as a refrigerant control
a. Evaporator
b. Condenser
c. Compressor
d. Expansion valve

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ANSWER KEY SELF-CHECK LO# 1

1. C
2. A
3. B
4. C
5. D

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QUALIFICATION : AUTOMOTIVE SERVICING NC II

UNIT OF COMPETENCY : Perform Maintenance Service Check-Up and Repair of
Air-Conditioning System

MODULE : Performing Maintenance Servicing Check-Up and
Repairing Air-Conditioning System

LEARNING OUTCOME #2 : Perform general check-up/service/repair and
replacement of auto air conditioning system
components

ASSESSMENT CRITERIA:

1. General servicing in completed without causing damage to any workplace
property or air conditioning system component.

2. Correct information is accessed and interpret from appropriate manufacturer.
3. Air conditioning system components as dismantled, reassembled and tested to

manufacturer specifications.
4. Worn damage, deteriorated or faulty components are identified and

replaced/repaired.
5. System components are tested prior to placing into service and results are

recorded in accordance with enterprise policies and procedures.
6. Air conditioning system components are over hauled according to industry

regulation/guidelines. OH and S procedure and company procedure/policies.

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LEARNING EXPERIENCES / ACTIVITIES

LO# 2 – Perform general check-up/service/repair and replacement of auto air
conditioning system components.

LEARNING ACTIVITIES SPECIAL INSTRUCTIONS

- Were you ~b1e to overhaul compressor
motor?

- Did you observe industry standard while
overhauling the compressor?

The next activities will develop your
competency in checking the AC system
operation

1. Identifying, describing and preparing a. Read: Automotive Service System,
tools and equipment needed in checking by; Harry (3. Hill pp. 319~434O
the AC system operation.
a. Reading on the use of test
instrument:
- Manifold gauge
- Temperature gauge

2. Starting Engine.
a. Reading service manual
b. Starting the engine

3. Checking AC system operation
a. Observing the operation of AC
system

4. Checking refrigerant leak and
unnecessary noise of AC system.
a. Reading information from reference
books
b. Checking the leak of hoses and joint
of AC system

You have performed all the activities in
checking and troubleshooting the AC
system operation. You may assess your
performance.

a. Returning borrowed tools
b. Housekeeping and 5S

Congratulations: You have completed all
the activities for the module in overhauling
Aircon compressor troubleshooting and
checking the AC system performance. You
are now ready to be assessed by your
instructor. Good Iuckl

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SELF CHECK LO#2

Parts and Purpose of A/C System Components

DIRECTIONS: choose the letter of the correct answer.

1. The purpose of the blower is to:
a. Suck air from the inside of the car cabin
b. Blow air past through the evaporator
c. Force air out of the car cabin
d. None of the above.

2. The purpose of receiver drier is to:
a. Air Filter
b. Filter Air and Liquid refrigerant
c. Received air and liquid refrigerant
d. Filter liquid and gas

3. The purpose of expansion valve is to:
a. Minimize the flow of refrigerant
b. Control the thermal load of refrigerant
c. Regulates the flow of refrigerant depending on the thermal load
d. Regulates the flow of liquid and gas.

4. The purpose of refrigerant is to:
a. Circulates the fluid inside A/C system
b. Cool the fluid inside A/C system
c. Lubricate the cooling coil
e. Protect damage of A/C system

5. The purpose of condenser is to:
a. Condense heat from the radiator
b. Mixture of air and gas
c. Radiate heat from the refrigerant to the surrounding air
d. Mixture of gas and liquid

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ANSWER KEY LO#2

1. A
2. B
3. D
4. B
5. C

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INFORMATION SHEET

Making Recommendations

Every problem has to be solved, every situation that requires thinking through must be
analyzed and its components discovered in order that a solution may be intelligently
reached.

Interpretation involves the valid use of evidence and the accurate use of reasoning. The
writer states his position by citing facts and authorities from the information he gathered,
and by reasoning from the evidences he presents.

How to Phrase Recommendations

To a certain extent, it is possible to classify recommendations as formal or informal.

An informal recommendation may consist merely of a statement like:

Example: It is recommended that detergent may be added to the lubricant.

Or : Therefore a detergent should be added to the lubricant.

In any sense, any suggestion or advice constitutes a recommendation. The formality with
which it should be presented is determined by its relation to the major problem being
discussed. Usually, the more important a problem is and the longer the discussion of it,
the more need there is for a formally phrased recommendation.

A highly formal recommendation is illustrated by the following example:

After consideration of all the information available concerning the problems just
described, it is recommended:

That the present sewage disposal plant may be expanded, rather that that a new one be
constructed;

That the present filter be changed to a high rate filter;

That a skilled operator be employed.

Sometimes each main clause in a recommendation like this is numbered. Sometimes the
recommendations are presented as a numbered list of complete sentences preceded by
the subhead “RECOMMENDATIONS” and without any other introduction.

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TASK SHEET

A/C SYSTEM PERFORMANCE

By making a systematic check of the functional components of the refrigeration cycle, it
is possible to detect malfunctions which the customer had hardly been aware of.
Moreover, early detection and proper repair of the trouble will prolong the quality service
of the components as well as ensuring that the customer will be spared of unwanted
trouble.

Keep in mind that the simplest and easiest way of detecting component malfunction is
through looking and listening.

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PERFORMANCE TEST

Learner’s Name Service Check-Up and Date:
Test Attempt
Competency: Perform Maintenance
Repair of AC System 1st 2nd 3rd

Directions: OVERALL EVALUATION PERFORMANCE LEVELS
Level
CALL INSTRUCTOR, ask
instructor to assess your Achieved
performance in the following
critical task and performance 4 – Can perform this skill without supervision and with initiative
criteria below. and adaptability to problem situations.

You will be rate based on the 3 – Can perform this skill satisfactorily without assistance or
overall evaluation on the right supervision.
side.
2 – Can perform this skill satisfactorily but requires some
assistance and/or supervision.

1 – Can perform parts of this skill satisfactorily, but requires
considerable assistance and/or supervision.

Instructor will initial level achieved.

PERFORMANCE STANDARDS Yes No N/A
For acceptable achievement, all items should receive a “Yes”
or “N/A” response.

1. Were tools and equipment prepared according to kind and size?

2. Were the functions and uses of the Auto-Air-con are explained?

3. Were component parts identified?

4. Were safe handling of tools properly observed?

5. Were standard specifications determined?

6. Was A/C compressor overhauled observing industry standard
operating procedure?

7. Were tools and equipment needed in checking A/C compressor
repair prepared?

8. Was A/C operating cycle explained?

9. Were procedures in checking A/C compressor observed?

10. Was operation observed in accordance with service manual
specifications?

11. Were the leakages and clogging checked?

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Record of Achievement

Module: Dismantling/Evaluating Engine Sub-Assembly/ Cylinder Heads

Learning Outcome #1 - Identify components and related parts of cylinder head.

Performance Criteria:

1. Components of engine sub-assembly/cylinder head are identified.
2. Functions and uses of cylinder head components are explained
3. Safe handling of parts are observed
4. Standard specification is determined

COMMENTS:
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………………………………………………………

Learner has satisfied the above performance criteria.

Learner signature: ……………………………………….

Trainer signature: ………………………………………..

Date: ……………………………………………………….

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Record of Achievement

Module: Performing Maintenance Servicing Check-Up and Repairing Air-Conditioning System

Learning Outcome #2 - Perform general check-up/service/repair and replacement of auto air
conditioning system components

Performance Criteria:

1. General servicing in completed without causing damage to any workplace property or air
conditioning system component.

2. Correct information is accessed and interpret from appropriate manufacturer.
3. Air conditioning system components as dismantled, reassembled and tested to manufacturer

specifications.
4. Worn damage, deteriorated or faulty components are identified and replaced/repaired.
5. System components are tested prior to placing into service and results are recorded in

accordance with enterprise policies and procedures.
6. Air conditioning system components are over hauled according to industry regulation/guidelines.

OH and S procedure and company procedure/policies.

COMMENTS:
…………………………………………………………………………………………………………………………
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………………………………………………………

Learner has satisfied the above performance criteria.

Learner signature: ……………………………………….

Trainer signature: ………………………………………..

Date: ……………………………………………………….

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DEFINITION OF TERMS

1. Evaporator — Atomized refrigerant evaporates into gas while taking heat away
from the surroundings through the action of the cooling fan. (the surrounding will
be cooled)

2. Expansion valve- Allows the refrigerant to rapidly expand into low temperature
and low pressure. (atomized)

3. Condenser — This is installed in front of radiator. Cools high pressure and high
temperature refrigerant to its condensation point to return to high pressure liquid
with air from the cooling fan and the vehicle speed

4. Receiver drier — Removes moisture and dirt contained in the refrigerant and
stores it to enable a smooth supply of refrigerant.

5. Blower — Feeds air in the vehicle under pressure to the evaporator and feeds
cooled air into the vehicle.

6. Compressor — This is driven by V-belt from the engine to change the
evaporated refrigerant into high pressure, high temperature gas and supply it to
the condenser. The magnetic clutch is installed to enable stopping of the
compressor.

7. Refrigerant — is a substance use to produce refrigeration by expansion or
evaporation

8. Cycle — Series of events repeated all over again.

9. Air-conditioning — process of treating air as to control the humidity,
temperature dampness of air in a conditioned space.

10. Evaporation — process of changing liquid into gas.

11. Condensation — process of changing gaseous to liquid

12. Fan control knob — this knob turns the fan ON and OFF and control the
speed,

13. Mode Control Knob — this knob controls the outlet airflow

14. Temperature Control Knob — This knob allows adjustment of the temperature
of the outlet air.

15. Air- conditioner Switch — The air conditioner switch controls A/C system.
When the switch is depressed with the fan ON, the compressor will turn ON, The
indicator lamp will also light

16. Recirculation (Rec) Switch — OFF position outside air is drawn into the
passenger compartment. ON position interior air is circulated inside the vehicle.
The indicator lamp will also light.

17. Humidity — water vapor contained in the air.

18. Temperature — is the degree of heat or coldness of an object

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Resource Pack

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SHOP HAND TOOLS

After studying this module, you should be able to:

• Describe the four types of basic hand tools used in the automotive shop, and give two
examples at each.

• Explain the difference between a torque wrench and a torque-angle gauge, and
demonstrate their use.

• Show how to remove a broken bolt or stud.
• Demonstrate how to select, set up, and use a pressure-screw puller and a slide-

hammer puIler.
• Show how to cut threads on a rod and in a hole using a tap-and-die set.

HAND TOOLS AND POWER TOOLS

Automotive service work requires a great variety of tools. The proper tools properly used
enable you to do a job with safety, speed, and efficiency. You need two main types of
tools in the shop. These are hand tools and power tools.

This chapter covers hand tools. Your hand supplies the energy to use them. They
include striking, turning, gripping, and cutting tools. They also include tube bending and
flaring tools.

Power tools or machine tools use an energy source other than your muscle power.

STRIKING TOOLS

HAMMERS

A hammer is a hand tool used for
striking. The ball-peen hammer is
the one used most in the shop. Grip
the hammer on the end of the
handle. Swing it so the hammer face
strikes the object or surface
squarely. Avoid hitting the object at
an angle. Use rawhide. plastic,
brass, and rubber hammers to strike
easily marred surfaces. A dead-blow
hammer has a hollow head partially
filled with small metal shot. This
reduces rebounding.

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TURNING TOOLS

SCREWDRIVERS

Use the proper screwdriver to drive or
turn screw. Screwdrivers are made in
a variety of sizes, shapes, and
special-purpose designs. The most
common type has single flat blade for
driving screws with slotted heads.
There are also Torx-head and
Phillips-head screw drivers. Always
select a screwdriver of the proper
type and aid for the job. When using a
single-blade screwdriver, the blade
should completely fill the screw slot.
This helps prevent damage to the
screw, head.

WRENCHES

A wrench is a long-handled tool with
fixed or adjustable jaws. You use a
wrench to turn bolts, nuts, and screw.
To work on both USC and metric
fasteners, you need both USC and
metric wrenches. A 3/8- to 1-inch USC
set and a 6- to 19-mm metric set will
handle most jobs. You need these sizes
in sets of open-end, box, and
combination wrenches.

A set of hand tools used by the
automotive technician.

Types of wrenches.

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OPEN-END WRENCH Open-end wrench.

Open-end wrench usually has the jaw
opening at a 15 degree angle to the
handle. Turn the bolt or nut as far as the
space permits. Then flip the wrench over
for further turning of the fastener.

An open-end wrench has a different size on each end, make sure the wrench fits snugly
against the flats. These are the sides of a nut or bolt head. A loose fit may spring the
jaws of the wrench. Springing jaws spread apart would round off the corners of the hex.
This makes use of the proper wrench more difficult.

Never use an open-end wrench to final-tighten a fastener or to free a frozen fastener.
The jaws may spread enough to allow the wrench to slip. Use a box wrench or socket
wrench for these jobs.

BOX WRENCH

The box wrench opening surrounds or Set of box wrenches.
“boxes in” the nut or bolt head. An
advantage is that the box will seldom
slip off. However, you must lift the box
wrench completely off and then place it
back on for each swing. The wrench-
head is thin for use in tight places. The
head usually sets at a 15-degree angle
to the body. This provides hand
clearance for swinging the wrench.
The most common box wrench has 12
notches or “points” in the head. This
allows turning the fastener if the wrench
can swing 30 degrees. A six-point box
wrench holds better on a nut or bolt but
needs a greater swing. The box wrench
has different-size openings on each
end.

COMBINATION WRENCH

The combination wrench has a box on Combination wrench.
one end and an open end on the other.
The two ends are usually the same size.
The box end is more convenient for
breaking loose or final-tightening a nut
or bolt. But you must lift the box
completely free after each swing. The
open end is more likely to slip off.
However, once the fastener is loose, the
open end can turn it faster.

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FLARE-NUT WRENCH

A flare-nut (crowfoot) wrench is a Flare-nut wrenches.
special type of combination or box-end
wrench. It is used to attach or loosen a Caution: Do not turn the flare nut without holding
flare nut or tubing nut. The ends of the the coupling nut. This will usually twist
flare-nut wrench are thicker than on and break the metal tube.
other wrenches. This helps prevent
slipping and rounding off the points on
soft-metal tube fittings. The tip point box
end has one of the flats cut off. The
opening is large enough to slip over the
tube.
Most flare nuts attach to a coupling nut.
Hold the coupling nut while turning the
flare nut.

ADJUSTABLE WRENCH

An adjustable wrench has a movable
jaw that you adjust to fit nuts and bolt
heads of various sizes. Tighten the jaws
against the flats of the nut or bolt before
applying a turning force. Adjustable
wrenches are normally used only when
applying relatively light torque. They are
not always strong as fixed jaw wrenches
and may be damaged as excessive
torque is applied.

How to use an adjustable wrench.

SOCKET WRENCH

Socket wrenches are the Set of sockets w/ handles, extensions, and universal joints.
most widely used tool in
the shop. They are like
box wrenches except that
the head or socket is
detachable form the
handle. You assemble the
socket wrench you need
from the socket set in your
toolbox and attach it to the
handle. There are several
kinds of sockets. The 12-
point socket is the most
common.

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The drive lug is square and always sized in fractions of an inch. Common drive lug sizes
are ¼, 3/8, and ½ inch. The 12-point socket allows you to reach bolt or nut in tight spots.
However, if a bolt head or nut has rounded corners or excessive resistance to turning,
the 12-point socket may slip. Use a six-point socket for these. The eight-point socket is
for turning square heads. They include drain plugs, fill plugs, and pipe plugs. Spark plugs
are removed using a spark-plug socket. This is a six-point deep socket with a rubber
insert. The insert holds the plug to prevent it from falling out of the socket.

Several handles are available for sockets. The ratchet handle has a mechanism that
permits free motion in one direction but lockup in the other. You select the direction for
lockup by moving the reversing lever.

Extensions of various lengths provide access to hard-to-reach bolts or nuts. The
universal joint allows you to turn a nut or bolt while holding the driver at an angle.
Adapters allow you to use a driver with a socket having a different drive size. Also,
various kinds and sizes of screwdrivers, Torx drivers, Allen wrenches, and flare-nut
wrenches will fit the drive and adapters.

TORQUE WRENCHES

A torque wrench is basically a How a socket attaches to a ratchet handle.
special handle for a socket. An
indicator on the torque wrench
measure the torque or twisting
force. This is the amount of
force applied to a nut or bolt
while tightening it. Vehicle
service manuals and auto repair
manuals give the torque
specification for most fasteners.
A typical specification might be
to tighten a bolt to “20 lb-ft.”
This means to apply a 20-pound
pull at a distance of 1 foot from
the bolt.
To use the torque wrench,
attach the proper socket. Place
the socket on the nut or bolt
head. Then pull on the wrench
handle. When the torque
wrench indicates the specified
torque, the bolt or nut is
properly tightened. However,
the threads must be clean and
in good condition.

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Dirty or damaged threads Types of torque wrenches.
put a drag on the threads as
the bolt or nut is tightened.
This gives a false reading
on the torque wrench. It can
also result in not enough
tightening.
Many torque wrenches read
in pound-feet (lb-ft) read in
pound-inches (lb-in). Use
these where you need to
accurately apply a small
torque.

Twelve pound-inches equals one pound-foot.
The scale on metric torque wrenches is in kilogram meters (kg-m), kilogram-centimeters
(kg-cm), or Newton-meters (N-m). Newton-meters is the preferred unit to convert from
USC to Newton-meters, multiply pound-inches by 1.35.

TORQUE-ANGLE GAUGE

Tighten torque-to-yield bolts to an initial
torque with a torque wrench (7-11).
Then final-tighten the bolt by turning
them through a specified angle with a
socket wrench.
You can easily see a 90-degree turning
angle by watching how far a ratchet
handle or breaker bar moves. From
other angles, use a torque-angle gauge.
This accurately measures the turning
angle in degrees.

Torque angle gauge.

The gauge attaches to the socket driver. The socket attaches to the gauge. As the
handle turns, the degree indicates remains at the greatest angle reached.

REMOVING FROZEN NUTS AND BOLTS

When a nut or bolt is frozen, try applying penetrating oil on the threads. Give the
penetrating oil time to soak in then try rotating the bolt or nut with a suitable spanner or
socket wrench. Tapping lightly on the bolt head with a hammer may help. If all else
failed, use a chisel, nut cracker or splitter to split off frozen nuts.

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GRIPPING TOOLS

Pliers

These are hand tools with a pair Various types of gripping pliers and cutting pliers.
of adjustable jaws for gripping.
There are many styles and sizes
of pliers. Combination, slip-joint
pliers may have cutting edges at
the back of the jaws for wire
cutting. Tongue-and-groove or
groove-and-land pliers such as
Chennellock pliers have the
tongues or lands on one jaw.
The grooves are on the other.
Shifting the tongues or lands to
different grooves changes the
distance the jaws can open. The
jaws remain parallel at any
setting.
Locking pliers such as vise-grip
pliers have locking jaws. This
makes them useful as pliers,
wrenches, clamps, and small
vises.

Lock the jaws by turning a screw in one
end of the handle. This adjusts the size of
the opening. Closing the handles then
locks the jaws into place. To release the
jaws, pull the release lever.
Combination pliers can be used as hose
clamp pliers by drilling holes in the jaws.
You can then use the pliers to remove
and install spring-wire hose clamps.

Caution: Never use gripping pliers on
hardened steel surfaces. This dulls
the pliers’ teeth. Never use pliers on
nuts or bolt heads. The pliers may
slip and round off the edges of the
hex. Then a wrench or socket will
not fit on the fastener properly.

How to adapt combination pliers so they can
handle spring-wire hose clamps.

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REMOVING BROKEN BOLTS AND STUDS

Excessive torque applied to a bolt or stud Using a stud extractor to remove a broken stud.
may cause it to break. For example,
suppose a bolt or stud is damaged, rusted
or stretched. Then the bolt or stud may
break as you apply the specified torque.
When a threaded fastener breaks,
approach the problem logically. You must
remove the broken part. Be patient and
be careful not to create an even bigger
problem. Removal methods to try depend
on where the break occurred on the
fastener.

1. Break above surface – When the break is above the surface, you may be able to file
flats on two sides. Then use a wrench to back out the broken part. Sometimes you
can cut a slot in the bolt. Then remove it with screwdriver. Another way is to attach
locking pliers to the threads, then turn the bolt out.

2. Break close to surface – If the break is close to the surface, try removing the bolt with
a center punch on the bolt, but off center, then tap the punch lightly with a hammer.
By moving the punch and tapping it, the bolt may back out.

3. Break below surface – Sometimes the break is near or below the surface. Try
removing the broken bolt with a bolt or stud extractor. Center-punch the bolt and then
drill it. Use a drill that makes a hole as large as the inside diameter of the threads,
then use an extractor of the proper size to remove the bolt.

Caution: Extractors are hard and brittle. Excessive force may break the extractor. A broken
extractor can be more difficult to remove than the broken bolt. If a reasonable turning
force on the extractor does not turn the bolt, remove the extractor. Drill out the hole to
remove the rest of the bolt and retap the hole or install a thread insert.

PULLERS

Pullers remove parts assembled with an
interference fit. This includes removing
gears and hubs from shafts, and bearings
from blind holes. Pullers also remove seals
from axle and cylinder liners from engine
blocks.
The puller set has many pieces that can fit
to form the puller needed for the job. There
are three basic types of pullers. These are
pressure screw, slide hammer and
combination.

Using a screw puller to remove a steering
wheel.

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Removing an axle seal with a slide-
hammer puller.

CUTTING TOOLS

Cutting tools remove metal. They include chisels, saws, files, punches. Drill, taps and
dies are also cutting tools. Power cutting tools include grinders, hones and boring
machines.

Chisels

The chisel is a cutting tool with a single
cutting edge. There are various sizes
and shapes of chisels. Striking the chisel
with a hammer makes the chisel cut.

Caution: Always wear eye protection
when using a chisel. Never use a chisel
with a mushroomed head. When the
hammer strikes the head, a piece could
fly off. The flying metal could cut you or
injure an unprotected eye.

Various types of chisels.

HACKSAW

A hacksaw is basically an adjustable metal
frame that holds a steel saw blade. The
blade is replaceable and has from 14 to 32
teeth per inch. Cutting occurs on the
forward stroke as you push the blade
across the metal. The teeth act like tiny
chisels and cut off fine shavings or chips.
Use a long steady forward stroke. Apply
enough downward force so the teeth cut
rather than slide.

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Lift then down force on the return stroke. This helps prevent dulling the teeth. A light drag
may help clear chips from the teeth.
Select a blade with the proper number of teeth per inch for the job. The teeth must be
close enough so at least two teeth are cutting. Teeth that are too close together clog and
stop cutting. The hacksaw blade for general cutting has 14 teeth per inch.

FILES

Files are used for cutting and shaping Parts of a file.
metals, they have many cutting edges or
teeth. There are many types of files with
various “cuts”. When these cuts are far
apart, there are only a few per inch.

This is a rough or coarse-cut file. When the
cuts are close together, the file is a smooth
or dead-smooth file. A single-cut file is a
series of sharp blades. A double-cut file
has a second cut at an angle to the first.
This creates a series of teeth. Various
sizes and cuts of round, half-round, and
triangular files are used during automotive
service jobs. Always use a handle with a
file. Tapping the end of the handle on the
bench tightens the file in the handle. Keep
the file teeth clean with a file card. It has
short stiff-wire bristles that remove chips
and dirt from the teeth.

PUNCHES

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Punches are used to knock out rivets and
pins. They also align parts for assembly.
To remove a rivet, grind off the rivet head
or cut it off with a chisel then use the
starting punch and pin punch.

Various types of punches.

Mark spots where holes are to be drilled
with a center punch. The punch mark
keeps the drill bit centered as it starts
cutting. You can use the center punch to
mark parts before they are disassembled.
Align the punch marks to reassemble the
parts in the same position.

Center-punching a hole location will keep the
drill from wandering.

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TWIST DRILLS

Drill bits or twist drills are tools for making holes. The material being drilled determines
the preferred shape of the cutting edges that form the point. The grooves along the body
carry the chips out of the hole. A hand-held air or electric drill motor, or a drill press
drives the drill bit.

TAPS AND DIES

Most shops have tap-and-die sets for
cutting USC and metric threads. Taps cut
inside threads. To tap a hole, determine
the thread size needed. Refer to a tap drill
chart and select the size of drill bit
required.

The hole made by the specified tap drill will
be the proper diameter for tapping.
Dies cut outside threads on rods. A
diestock holds the die. Chamfer or bevel
the rod end so the die starts easily. The
basic procedure is the same for both taps
and dies. Apply cutting lubricant to the
surface, then begin thread cutting. After
every two turns, back off the tap or die and
apply more lubricants.

Tap being used to cut threads in a hole.

Note: You can use taps and dies to clean
and straighten damaged threads. However,
a thread chaser is the preferred tool for this
job.

Die being used to cut threads on a rod.

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