Republic of the Philippines

Department of Education
N a t i o n a l C a pi t a l Re g i o n
Sc h o o l s D i v i s i o n O f f i c e o f La s Pi ñ a s C i t y

NAME: ___________________________________________ Date: ______________________

GRADE & SECTION ____________________________ Teacher: ___________________

MODULE IN AUTOMOTIVE SERVICING NCII

Grade 12
Fourth Quarter
Week 1

MOST ESSENTIAL LEARNING COMPETENCY

o Perform carburetor adjustment – (TLE_IAAUS9-12SGF-IIg-i-30)

Objectives:
1. Perform carburetor adjustments according to industry operating
procedures.
2. Perform overhauling of carburetor in accordance with the required
procedures.
3. Apply and use proper tools and equipment in accordance with the
industry standard.

PRE-TEST: MULTIPLE CHOICE (10 points)

Directions: Read each item carefully. Write the letter that correspond to your
answer. Write your answers in a separate sheet.

1. What part of the fuel system works to controls the rate at which air flows
through the venturi?
A. Accelerator pump C. Metering jet
B. Mixture control D. Throttle valve
2. What is the following situation called? The mixture explodes rapidly and
produces wildly fluctuating pressures, could cause engine failure if
severe.
A. Detonation C. Pre-ignition
B. Idle cut-off D. Over rich mixture
3. What part of the fuel system ensures the sufficiency of fuel, for engine
operation when the throttle control is closed?
A. Accelerating system C. Idling system
B. Enrichment system D. Idle cut-off system

2
 4. What should you do if detonation is experienced?
A. Increase airspeed C. Reduce airspeed
B. Lean the mixture D. Reduce throttle setting
5. What is the purpose of the venturi in the carburetor?
A. To draw out the fuel from the nozzle
B. To heat up the fuel/air mixture for evaporation
C. To cool down the fuel/air mixture for evaporation
D. To accelerate air so the throttle butterfly doesn’t flutter
6. Why does a carburetor have an atomization and diffusion system?
A. To improve vaporization of the air
B. To improve vaporization of the fuel
C. To distribute the mixture to each cylinder
D. To condense the mixture for smoother flow through the manifold
7. Why is a mixture control required?
A. To increase the rate of mixture flow
B. To regulate the amount of air being metered
C. To regulate the amount of fuel being metered
D. To increase the rate of fuel flow as throttle is opened
8. What will an over-rich mixture most likely create?
A. Detonation due to too much fuel
B. Pre-ignition due to too much fuel
C. Detonation due to not enough fuel
D. Pre-ignition due to not enough fuel
9. What will an over-lean mixture most likely create?
A. Detonation due to too much fuel
B. Pre-ignition due to too much fuel
C. Detonation due to not enough fuel
D. Pre-ignition due to not enough fuel
10. Why should the engine have stopped using idle cut-off?
A. To ensure no fuel is left in the tanks
B. To ensure no fuel remains in the system
C. Because turning the magnet to OFF could cause damage
D. Because the engine would detonate if the magnet alone were used

Carburetor

The principles of supplying an engine with the right amounts of fuel and air
have not changed over the years. However, stricter exhaust emission laws and
the need for improved fuel economy have changed carburetor requirements.
Today’s carburetors use numerous devices to alter the air-fuel ratio with changes
in engine speed, temperature, and load.
A carburetor is basically a device for mixing air and fuel in the correct
proportions (amounts) for efficient combustion. The carburetor bolts to the
engine intake manifold. The air cleaner fits over the top of the carburetor to trap
dust and dirt.

3
 When the engine is running, downward moving pistons on their intake
strokes produce suction in the intake manifold. Air rushes through the
carburetor and into the engine to fill this low pressure. The airflow through the
carburetor is used to meter fuel and mix it with the air.

Basic Carburetor Parts

1. Carburetor Body- main carburetor housing

2. Barrel- air passage containing venture, throttle valve and main discharge
tube
3. Throttle Valve- airflow control valve
4. Venturi- restriction or narrowed area inside the barrel
5. Main Discharge Tube- fuel passage between fuel bowl and barrel
6. Fuel Bowl-fuel storage area in body

Carburetor Removal

PROCEDURE:
1. Before removing the carburetor, check the operation of the idle solenoid
valve. Remove the wire from it, then turn on the ignition (do not start the
car). Touch the wire to the electrical connector on the idle solenoid valve.
You should hear a distinct "click." If you hear the click, the valve is okay --
otherwise, it must be replaced. Turn the ignition off.
2. Disconnect the hoses and blow-by tube from the oil filler to the air cleaner,
then remove the air cleaner and set it aside.
3. Detach the fuel hose from the carburetor and quickly plug it to minimize
fuel leakage (a pencil works great for this).
4. Detach vacuum hoses if you have them; if you have no vacuum hoses,
remove the caps from the vacuum ports on the carburetor.
5. Disconnect the wire to the automatic choke heating element ( #40 in the
exploded illustration)
6. Disconnect the wire to the electromagnetic cutoff valve (#16 in the exploded
illustration).
7. Loosen the screw in the accelerator cable barrel clamp; pull the cable
forward out of the pin. Stow the cable barrel clamp and screw in a safe place
so you can find them later (small parts).
8. Remove the distributor cap to provide access, then remove the two nuts
(13mm) from the studs on the carburetor flange. Make sure to have the
front nut brightly lit so you can see what you're doing.

4
9. Remove the carburetor and gasket; there will be a new gasket in your kit,
but try to maintain the integrity of the old gasket, "just in case." Stow the
two nuts in a safe place.
10. Put a rag into the open intake manifold to keep foreign material out.

Adjusting Engine Idle Speed Procedure:

The correct idle speed adjustment is important with any carburetor, which
is a complicated part for any gasoline engine. Some late carburetors have three
separate fuel circuits in them (only two in older carburetors), and the 850-900
rpm idle is designed so the airflow through the carburetor is balanced for the
idle circuit fuel flow. That's why it has both Volume and Bypass screws in the
side (the earlier ones had only Volume screw), located on the left side of the
carburetor. This way the idle speed can be set correctly using the Bypass screw
without touching the screw on the throttle arm, which has to be set exactly right.

Refer to the exploded view as you go on.

1. Make sure that all the hoses are in place and the gasket at the base of the
carburetor is sealing properly (no vacuum leak).
2. Install the air cleaner
3. Turn on the engine and run it until it is warm, then switch it off.
4. The first step is to set the throttle plate. Back off the Fast Idle Adjuster (also
called the throttle screw) located at the top of the throttle arm. You will find
the throttle arm on the left side of the carburetor, connected at the bottom
to the accelerator cable, which runs forward to the accelerator pedal.
Fast Idle Adjuster is NOT used to adjust the idle speed. The Fast Idle
Adjuster works with the choke to give a smooth idle on a cold engine. As
the choke warms (in concert with the warming engine, hopefully) the
butterfly valve in the throat of the carburetor opens and the Fast Idle
Adjuster screw moves down the steps of the choke fast idle cam, reducing
the engine idle speed. Screwing the Fast Idle Adjuster screw in more will
increase the idle speed, but doing so messes up the Volume Control and
Bypass Screw adjustments. This destroys the idle geometry, and the car
won't run right.
5. With the choke held in the fully open position (stepped cam at its lowest
point), place a 0.003" feeler gauge between the lowest step of the choke fast
idle cam and the Fast Idle Adjuster screw.
6. Slowly turn the screw in until you feel drag on the feeler gauge. Then remove
feeler gauge and turn the screw in precisely 1/2 turn. This sets the throttle
butterfly open the required 0.004", so you can use the Bypass Screw to set

5
 the idle speed correctly. From this point on, leave the Fast Idle Adjuster
screw alone.
7. Next set the volume of gas available at idle speeds. This is done using the
Volume Control Screw. Please note that the Volume Control Screw controls
the AIR volume, not the fuel volume. Screwing it in reduces the air and
makes the fuel/air mixture richer. And of course turning the Volume
Control Screw out increases the concentration of air and makes the mixture
leaner.
The Volume Control Screw is the smaller of the two adjusting screws,
located on the left side of the carburetor just above the Idle Cutoff solenoid
(which has a black wire from the positive side of the coil attached to it). The
Volume Control Screw is NOT used to set the idle speed - that's the job of
the Bypass Screw.
Before setting the Volume Control Screw per the step below, turn
the Bypass Screw (the larger one) out a couple of turns, just to get things
started.

8. Screw the Volume Control Screw in GENTLY until it sits. Never screw it in
tightly; you will destroy the seat. Now unscrew it exactly 2-1/2 turns. This
is the initial setting.
Note: Be sure that the Volume Control Screw firmly seated, you may have trouble
adjusting the idle with the Bypass Screw if it does not properly seated. This
condition will cause stumbling on acceleration if not corrected.

9. With the Volume Control Screw out 2-1/2 turns, start the engine and let it
warm up. (Make sure the choke is fully open.)

10. Now to set the idle. This is done by controlling the volume of air going by
the Bypass Screw. The Bypass Screw is larger than the Volume Control
Screw and is located a little above and to the left of the Volume Screw.
Again, the idle speed is NOT set with the Fast Idle Adjuster on the top
of the throttle arm as it is on the older carburetors - though its name (Fast
Idle Adjuster) would lead you to think that it is used to set the idle. It is not
used to set the idle.

11. Connect a tachometer to the engine as detailed in the manufacturer's

instructions.
➢ On models having a conventional ignition system, one lead (usually black)
goes to a good chassis ground. The other lead (usually red) goes to the
distributor primary side of the coil (the terminal with small wire running
to the distributor body).

6
 ➢ On models with transistorized ignition, connect one lead (usually black) of
the tachometer to a good chassis ground. Connect the other lead (usually
red) to the negative (-) coil terminal, NOT to the distributor or positive (+)
side. Connecting the tachometer to the wrong side will damage the
switching transistor.
12. As a starting point, turn the idle Bypass Screw out to set the idle at 850
rpm (fast idle). For a semi-automatic car, use 900 rpm. It is better to start
from a little bit higher rpm going down than to start from low rpm up.
13. With the engine warmed up and the choke fully open, go back to the
Volume Screw and adjust it slowly to obtain the fastest (smoothest running)
idle speed (this is usually out - counter-clockwise). You should not turn the
screw out much outside the range of 2-3 turns (1/2 turn in/out from the
basic 2-1/2 turn out setting).
14. Then turn the Volume Control screw back IN (clockwise) very slowly until
the engine speed drops by about 20-30 rpm (slightly leaner). Look at your
tachometer. If you don't have a tachometer, listen until you can just hear
the engine speed start to drop, maybe as little as 1/8th turn on the Volume
Screw.
15. Go back to the larger Bypass screw again to reset the idle speed to 850 -
900rpm. (Again, the fast idle is better than too slow. You want it just a little
on the rich side. Too slow of an idle speed can cause the engine to overheat.)
If you find it difficult or impossible to make these settings, it is
possible that you could have stripped threads on any of these adjusters, a
damaged hole for the tapered screw, or a damaged needle valve or O-ring.
It is also possible that you have a vacuum leak (i.e., leaking of air
into the intake manifold). If there are any holes in the manifold or at any of
the connection points, then air can be sucked into the manifold, causing
the fuel-to-air mixture to become too lean. This can cause (among other
things) adjustment of the carburetor impossible.

POST-TEST: MULTIPLE CHOICE (10points)

Directions: Read each item carefully. Write the letter that corresponds to your
answer. Write your answers in a separate sheet.

1. The mixture explodes rapidly and produces wildly fluctuating pressures,

could cause engine failure if severe. What is the following situation called?
A. Detonation C. Pre-ignition
C. Idle cut-off D. Over rich mixture

7
2. What part of the fuel system ensures the sufficiency of fuel, for engine
operation when the throttle control is closed?
A. Accelerating system C. Idling system
B. Enrichment system D. Idle cut-off system
3. What part of the fuel system works to controls the rate at which air flows
through the venturi?
A. Accelerator pump C. Metering jet
B. Mixture control D. Throttle butterfly
4. What should you do if detonation is experienced?
A. Increase airspeed C. Reduce airspeed
B. Lean the mixture D. Reduce throttle setting
5. Why does a carburetor have an atomization and diffusion system?
A. to improve vaporization of the air
B. to improve vaporization of the fuel
C. to distribute the mixture to each cylinder
D. to condense the mixture for smoother flow through the manifold
6. Why is a mixture control required?
A. To increase the rate of mixture flow
B. To regulate the amount of air being metered
C. To regulate the amount of fuel being metered
D. To increase the rate of fuel flow as throttle is opened
7. What will be the probable cause of an over-rich mixture in the
carburetor?
A. Detonation due to too much fuel
B. Pre-ignition due to too much fuel
C. Detonation due to not enough fuel
D. re-ignition due to not enough fuel

8. What will be the probable cause of over-lean mixture in carburetor?

A. Detonation due to too much fuel
B. Pre-ignition due to too much fuel
C. Detonation due to not enough fuel
D. Pre-ignition due to not enough fuel
9. What is the purpose of the venturi in the carburetor?
A. To draw out the fuel from the nozzle
B. To heat up the fuel/air mixture for evaporation
C. To cool down the fuel/air mixture for evaporation
D. To accelerate air so the throttle butterfly doesn’t flutter
10. Why should the engine be stopped using idle cut-off?
A. to ensure no fuel is left in the tanks
B. to ensure no fuel remains in the system
C. because turning the magnet to OFF could cause damage
D. because the engine would detonate if the magnet alone were used

8
 NAME: ___________________________________________ Date ______________________
GRADE & SECTION ____________________________ Teacher: ___________________

MODULE IN AUTOMOTIVE SERVICING NCII GRADE 12

Grade 12
Fourth Quarter
Week 2

MOST ESSENTIAL LEARNING COMPETENCY

o Perform calibration and installation of diesel fuel injector
TLE_IAAUS9-12SDF-IIIh-j-35

Objectives:
1. Explain the function and uses of diesel fuel injector.
2. Determine diesel fuel injector standard specifications.
3. Dismantling fuel injector based on service manual.
4. Explain the calibration and installation process.

PRE-TEST: MULTIPLE CHOICE (10 points)

Directions: Read each item carefully. Write the letter that corresponds to your
answer. Write your answers in a separate sheet.

1. Which of the following is used of fuel injector?

A. Compression-ignition engine C. Steam engines
B Spark-ignition engines D. Sterling engines
2. Which of the following stroke where the fuel is injected?
A. Compression stroke C. Expansion stroke
B Exhaust stroke D. Suction stroke
3. What is the range of pressure is achieved in the injection pump?
A. < 10bar C. 120 – 200 bar
B 10 – 20 bar D. 400 – 500 bar
4. In pneumatic governor, which of the following control the amount of
vacuum applied to the diaphragm?
A. Accelerator pedal C. Lever
B. Butterfly valve D. Spring
5. Which of the following is not the part of the injector assembly?
A. Compressor spring C. Needle valve
B Diaphragm D. Nozzle
6. Which of the following is not the function of the fuel injection system?
A. Atomize the fuel to fine particles C. Filter the fuel
B Control the engine speed D. Time the fuel injection

9
 7. What are the compositions of diesel injector assembly?
A. A needle valve C. A nozzle and an injector body
B A compression spring D. All of the mentioned
8. What type of valve is needed to supply sufficient force in able to lift the
injection pump?
A. Nozzle valve C. Throttle valve
B Mechanical valve D. None of the mentioned
9. In what particular process where there is a spring tension that leads to
the opening of the valve making the pressure controlled?
A. Top C. Bottom
B Center D. none of the mention
10. A six-cylinder, four-stroke diesel engine develops a power of 200 kW at
2000 revolution per minute. The brake specific fuel consumption is 0.3 kg
/ kW – h. What is the time for injection if the injection takes place over 20°
crank angle?
A. 1 millisecond C. 1.66 milliseconds
B 1.5 milliseconds D. 2 milliseconds

Diesel Injector

When signaled by the engine control unit the fuel injector opens and
sprays the pressurized fuel into the engine. The duration that the injector is open
(called the pulse width) is proportional to the amount of fuel delivered.
Depending on the system design, the timing of when injector opens is either
relative each individual cylinder (for a sequential fuel injection system), or
injectors for multiple cylinders may be signaled to open at the same time (in a
batch fire system).

Fuel injection is a system for admitting fuel into an internal combustion

engine. It has become the primary fuel delivery system used in automotive
engines, having replaced carburetors during the 1980s and 1990s. A variety of
injection systems have existed since the earliest usage of the internal combustion
engine.

The primary difference between carburetors and fuel injection is that fuel
injection atomizes the fuel by forcibly pumping it through a small nozzle under
high pressure, while a carburetor relies on suction created by intake air
accelerated through a Venturi tube to draw the fuel into the airstream.

Modern fuel injection systems are designed specifically for the type of fuel
being used. Some systems are designed for multiple grades of fuel (using sensors
to adapt the tuning for the fuel currently used). Most fuel injection systems are
for gasoline or diesel applications.

10
Mechanics of diesel fuel injectors

Basic diesel fuel injectors contain a fuel supply line, an intake valve, an
exhaust valve and the fuel injection apparatus. Each cylinder is attached to its
own fuel supply line, all of which run from the fuel tank to the engine. Fuel is
transferred through these fuel supply lines to the fuel injector device attached to
each cylinder. Along the way, the fuel passes through a filter that removes
residue and impurities.

When the diesel fuel reaches the injector device, it becomes highly
pressurized. The fuel injector is attached to a small pump, which forces air into
the injector and pressurizes the diesel fuel. The injector then sprays the diesel
fuel through a small nozzle into the cylinder's combustion chamber. The nozzle
contains a series of small holes, which ensure even distribution of the diesel fuel
into the cylinder's combustion chamber.

An air intake valve sucks air into the chamber, which mixes with the
vaporized diesel fuel and intensifies the combustion. An exhaust valve removes
the resulting emissions from the combustion chamber, and a return fuel line
removes any excess fuel from the combustion chamber and returns it to the fuel
tank.

Advancements in Diesel Fuel Injectors

Diesel fuel injectors have become increasingly sophisticated and efficient

in recent years. Modern diesel fuel injectors are regulated by computers, which
monitor the amount of air entering the engine and regulate the amount of diesel
fuel that is sprayed into the combustion chamber. Fuel injectors have also been
modified slightly to accommodate the use of biodiesel fuel, which is diesel fuel
made from plant and animal oils rather than from petroleum.
Biodiesels are not as powerful as petroleum-based diesel fuel, so more
biodiesel fuel is required to run an engine. Hence, diesel fuel injector pumps
have become more powerful and more closely integrated with the system's
computer in order to ensure that the appropriate amount of fuel is delivered to
the combustion cylinder.

11
Diesel injection pump repair

A diesel injection pump refers to a device used to pump or send fuel into
the diesel engine's cylinders. Diesel injection pumps can malfunction for
numerous reasons; some basic troubleshooting techniques usually resolve the
problem.

Air in Fuel Lines

A loss of pressure results when air gets in the fuel lines of a diesel injection
pump, causing engine starting or stalling problems. Bleeding the fuel system of
air and checking for any leaks in the lines -- and replacing any lines as needed
-- typically corrects the pump problem.

Injector Clogging

Diesel injectors clog over time due to fuel sediment buildup in the nozzles.
Perform an injector overhaul every 100,000 to 150,000 miles, or as needed, to
restore proper diesel injection pump function.

Clogged Filter

A clogged fuel filter can keep a diesel injection pump from gaining access
to the fuel necessary to keep the engine running. The fuel filter should be
regularly cleaned of any dirt or sediment and replaced.

Injection Pump Problems

Injection pumps refer to devices used to pump fuel into diesel engine
cylinders. Injection pumps require precise timing, a high pressure environment
and the synchronization of numerous components. Issues involving any of these
factors can lead to injection pump problems

Rotor Seizing

The injection pump rotor, or pump component that connects to the

crankshaft in the distributor section, can seize or lock up due to lack of pump
lubrication. This lubrication shortage often results from a clog in the pump.
Under such circumstances, the pump and fuel filters should be checked for clogs
and lubrication should be added.

12
Ruptured Diaphragm

The diesel lift pump contains a diaphragm which fills with oil. A ruptured
diaphragm causes the pistons to vibrate and ultimately wear down. This results
in fuel bypassing the injection pump altogether, causing low or nonexistent fuel
pressure. Replacing the diaphragm and any worn pistons is necessary to restore
proper injection pump function.

Excess Air

Air entering the fuel lines due to cracks, leaks or other entry points results
in excess air being pumped by the injection pump. This leads to fuel pressure
loss, which can cause an engine to stall or not start altogether.

How to Troubleshoot a Diesel Fuel Injection

With the complexity of today's diesel engines, the sheer number of things
that can go wrong in such a system is maddening. The diesel fuel injection
system is the component of the diesel engine that pumps the fuel into the engine.
If this component is in some manner malfunctioning, it can reduce the
performance of your engine, cause unnecessary wear, or even prevent your
engine from starting. It is possible to troubleshoot a number of these problems
by yourself.

Instructions
1. Check for and clear any clogs in the distributor section of the fuel pump. These
clogs can cause the rotor to seize. These systems use the diesel fuel itself as a
lubricant.

2. Check for air in the fuel lines if you are experiencing problems either with
starting the engine or you experience stalling. If air gets into the lines it results
in a loss of fuel pressure in the system, thus leading to problems such as the
inability to start the engine or stalling.

3. Check for corrosion on the circuit board responsible for the regulation of fuel
flow into the system. Check the bottom of your injection pump for the
connections. If you find significant corrosion, you may need to replace the unit.
This problem results from the nature of the technology itself, with the designs
on which the injection system is based being older than, and not meant for, the
computer that controls it.

13
 4. Check your fuel filter(s) for clogging. Change them if necessary. This type of
routine maintenance is generally performed every 100000 to 150000 miles.

5. Check for water in the fuel system. If you find water, you will need to replace
or repair the splinter unit, which functions to remove water. Common symptoms
of water in the fuel system include stalling, poor performance, and not being able
to start the engine.

6. Check for a rupture of the diesel lift pump diaphragm. Signs of a rupture
include wearing of the piston. Symptoms of such a rupture include a lack of fuel
pressure or low pressure.
7. Check the calibration of the injection unit. If you suspect the calibration is off,
recalibration is usually accomplished at a manufacturer's service center. This
type of issue is usually found in new systems.

How to Tell if a Diesel Pump is Good

In both diesel engines and in gasoline engines, the fuel is injected into the
cylinders by a fuel pump. The pump is obviously a very important part of the
engine, since without it, the cylinders would not receive any diesel fuel. If you
recently purchased a diesel vehicle, or if you just have a sneaking suspicion that
the pump in your diesel is going bad, there are a few ways that you can determine
if the problem really is the pump. If you eliminate the problems, your fuel pump
is most likely fine.

Instructions

1. Listen for any moments of silence when your engine is running. Normally, you
can hear a study hum of the engine running. If this sound seems to stop
intermittently, the problem may be the diesel fuel pump. If your engine runs
steadily, this indicates that fuel pump is running well.

2. Try to start your engine. There are different sounds that an engine makes
when it is having certain problems. If the engine "cranks" -- sounds like it's trying
to start, but does not -- this indicates a problem with the fuel pump. If the engine
starts normally, the fuel pump is most likely good.

3. Focus on how the car runs when you are on the highway. If the vehicle
responds well to your gas and brake pedal, your fuel pump is functioning well.
If you notice that the car slows down even when you haven't let off the gas, your
fuel pump may need to be replaced.

14
4. Examine the fuel pump while the engine is moving. Check to make sure it is
running smoothly and that there are no obvious signs of rust or mutilation.

POST-TEST: MULTIPLE CHOICE (10points)

Directions: Read each item carefully. Write the letter that corresponds to your
answer. Write your answers in a separate sheet.

1. What is the range of pressure is achieved in the injection pump?

A. < 10bar C. 120 – 200 bar
B.10 – 20 bar D. 400 – 500 bar
2. In pneumatic governor, which of the following control the amount of
vacuum applied to the diaphragm?
A. Accelerator pedal C. Lever
B. Butterfly valve D. Spring
3. Which of the following is used of fuel injector??
A. Compression-ignition engine C. Steam engines
B. Spark-ignition engines D. Sterling engines
4. Which of the following stroke where the fuel is injected?
A. Compression stroke C. Expansion stroke
B. Exhaust stroke D. Suction stroke
5. In what particular process where there is a spring tension that leads to
the opening of the valve making the pressure controlled
A. Top C. Bottom
B. Center D. none of the mentioned
6. A six-cylinder, four-stroke diesel engine develops a power of 200 kW at
2000 revolution per minute. The brake specific fuel consumption is 0.3
kg / kW – h. What is the time for injection if the injection takes place
over 20° crank angle?
A. 1 millisecond C. 1.66 milliseconds
B. 1.5 milliseconds D. 2 milliseconds
7. Which of the following is not the part of the injector assembly?
A. Needle valve C. Nozzle and an injector body
B. Compression spring D. all of the mentioned
8. Which of the following is not the part of the injector assembly?
A. Compressor spring C. Needle valve
B Diaphragm D. Nozzle
9. Which of the following is not the function of the fuel injection system?
A. Atomize the fuel to fine particles C. Filter the fuel
B Control the engine speed D. Time the fuel injection

10. In what particular process where there is a spring tension that leads to
the opening of the valve making the pressure controlled?
A. Nozzle valve C. Throttle valve
B Mechanical valve D. None of the mentio

15
 NAME: ___________________________________________ Date ______________________
GRADE & SECTION ____________________________ Teacher: ___________________

MODULE IN AUTOMOTIVE SERVICING NCII

Grade 12
Fourth Quarter
Week 3

MOST ESSENTIAL LEARNING COMPETENCY

o Procedures in overhauling hydraulic clutch mechanism
TLE_IAAUS9-12SCL-IVe-f-39

Objectives:
1. Perform and follow installation procedures based on
manufacturer’s specification.
2. Perform procedure in replacing hydraulic valve mechanism
based on repair manual.
3. Perform procedure in setting clutch pedal free play based on
manufacturer’s specifications.

PRE-TEST: MULTIPLE CHOICE (10 points)

Directions: Read each item carefully. Write the letter that corresponds to your
answer. Write your answers in a separate sheet.

1. What are the two types of pressure plates?

A. Coil spring C. Extension spring
B Diaphragm spring D. Torsion spring

2. What part of the clutch system reduces friction between clutch fork
and pressure plate?
A. Clutch housing C. Pressure plate
B. Flywheel D. Throw out bearing

3. Which of the following parts of the cover assembly that hold the
pressure plate against the clutch plate?
A. Lever C. Springs
B. Thrust bearings D. Struts

4. What type bolts is located in the rear of engine, which encloses clutch
components and transmit bolts to the back?
A. Clutch housing C. Pressure plate
B. Flywheel D. Throw out bearing

16
 5. Which of the following is the coefficient of friction of the clutch plate?
A. 0.1 C. 0.8
B. 0.4 D. 1.3

6. What part of clutch system reduces friction between clutch fork and
pressure plate?
A. Clutch housing C. Pressure plate
B. Flywheel D. Throw out bearing

7. What type of clutch has a higher coefficient of friction, low pressure

plate pressure, lower clutch pedal pressure, and for smoother
operation?
A. Ceramic/Metallic clutches C. Organic clutches
B. Multi-disc clutches D. Throw out bearing

8. What part bolted to crankshaft, smooth iron face, wears well and
dissipates heat?
A. Clutch housing C. Pressure plate
B. Flywheel D. Throw out bearing

9. Where is the clutch located?

A Between transmission and engine
B. Between transmission and rear axle
C. Between transmission and differential
D. Between transmission and propeller shaft

10. What point thus the clutch actually wearing?

A. At highway speeds when the vehicle is in top-gear
B. While the clutch disc and the flywheel are spinning at different
speeds
C. While the engine and the transmission are spinning at the same
speeds
D. While the engine and the transmission are spinning at the different
speeds

Remove clutch unit

1. Remove the transaxle.

2. Suitably mark the pressure plate cover in relation to the flywheel to ensure
replacement to the original position.
3. Progressively loosen and remove the pressure plate retaining bolts, working
in a diagonal sequence across the assembly.
4. Remove the pressure plate and driven plate assemblies from the flywheel
noting the installation direction of the driven plate hub.
5. Remove the release lever and bearing assembly as one unit from the
transaxle clutch housing by pulling on the release lever adjacent to the pivot
to release the retaining clip.

17
6. Slide the release bearing from the lever.
7. If necessary, remove the rubber dust excluder from the clutch housing.

Check and inspect clutch system

1. Check the drive plate facing for wear, glazing or oil contamination. Renew the
driven plate if the facings are oil soaked, highly glazed or worn to within 0.3
mm of the rivet heads. If the facings are contaminated with oil the source of
the leak must be located and rectified.

2. If the driven plate is serviceable do not allow any cleaning solvent, grease or
oil to contaminate the plate facings.

3. Mount the driven plate between centers and check the runout using a dial
gauge. Renew the driven plate if the exceeds 0.8mm.

4. Check the driven plate for worn splines

and loose or damaged hub cushion
springs. If necessary, renew the driven
plate.
5. Check the pressure plate assembly for
wear on the diaphragm spring fingers,
cracked diaphragm spring and a
distorted cover. Check the pressure
plate face for wear, scoring, heat cracks
or burn marks. Minor scoring or burn
marks should be corrected with
sandpaper. If necessary, renew the
pressure plate assembly.
Flywheel, driven plate and pressure plate
https://www.howacarworks.com/basics/how-a-
car-clutch-works

6. Check the flywheel for heat cracks, burn marks or scoring. Minor scoring or
burn marks should be corrected with sandpaper. If necessary, renew the
pressure plate assembly.
7. Using a dial gauge, check the flywheel face runout. If the flywheel is scored
or the runout exceeds 0.1mm, renew the flywheel
8. Rotate the release bearing by hand and check that no roughness, wear and
lack of lubrication is evident. Do not wash the bearing in solvent as the
internal lubricant will be washed away.

18
9. Check the release lever, retaining clip, dust excluder and pivot for cracks,
wear, bend and damage. Renew the unserviceable parts as necessary.

Install the clutch and associated parts

1. Sparingly lubricate the release lever contact surfaces, the release bearing
contact surfaces and transaxle input shaft splines with molybdenum disulfide
lithium base grease. Slide the driven plate onto the transaxle primary shaft
and remove the excess grease.
2. Install the release bearing to the release lever ensuring that the spring clip is
correctly installed.
3. Ensure that the release lever retaining clip is installed in the release lever and
install the lever and bearing assembly to the transaxle. Position the lever over
the pivot and press on the lever firmly until the retaining clip is forced over
the head of the pivot. Check the release lever and bearing for smooth, free
operation.
4. Install the dust excluder to the clutch housing.
5. Install the driven plate to the flywheel in the direction noted on removal
ensuring that the raised section of the driven plate is facing away from the
flywheel. Using a clutch aligning tool, align the center of the driven plate with
the crankshaft. Alternatively, use a 16mm diameter round section of wood or
metal approximately 150 mm in length.
6. Install the pressure plate to the flywheel. If the original pressure is being
installed, that the mating marks are aligned.
7. Install and tighten the pressure plate retaining bolts progressively and evenly
in a diagonal sequence to the specified torque ensuring that the bolts adjacent
to the locating dowels are tightened first. Withdraw the aligning tool.
10. Install the transaxle to the vehicle as described in the Manual Transaxle
section.
11. Check and adjust the clutch pedal height and free travel as described later
in this section.
12. Road test the vehicle and check for correct clutch operation.

Hydraulic system

Bleed hydraulic clutch system

1. Ensure hydraulic cylinder is maintained at least three quarters full during
the following operations.
2. Remove the rubber cap from the slave cylinder bleeder valve and attach a
transparent hose to the bleeder. Immerse the open end of the hose in a
container partially filled with clean brake fluid.

19
3. Have an instant slowly pump the clutch pedal several times and hold the
pedal down.
4. Open the bleeder valve to allow the fluid and air to flow into the container.
Close the bleeder valve when all fluid and air stops flowing from the hose and
slowly release the clutch pedal.
5. Repeat operations (3) and (4) until a clear stream of fluid, void of air bubbles
flows into the jar.
6. Remove the hose, install the rubber cap to the bleeder and check the
operation of the clutch. If

Clutch pedal

Remove and install clutch pedal

1. Working inside the vehicle, remove the screws retaining the right hand side
lower dash panel to the dashboard below the steering column.
2. While supporting the lower dash panel, disconnect the wiring from the
radio/cassette speaker and the instrument cluster rheostat. Disconnect the
ventilation duct and rest the lower dash panel on the floor with the bonnet
cable still connected.
3. Disconnect the clutch pedal return spring.
4. Remove the clutch clevis pin and washer retaining the master cylinder
pushrod to the clutch pedal.
5. Remove pivot nut and bolt and withdraw the clutch pedal, sleeve and
bushes.
6. Inspect the pivot bolt and bushes for wear and damage. Check the pedal for
crack and wear in the pivot bush bore. Renew the required parts as
necessary.

Installation is the reversal of the removal procedure with attention to the

following points:

1. Lubricate the pivot bush and the pivot bolt with multipurpose grease.
2. Tighten the pivot bolt and nut to the specified torque.
3. Check the clutch pedal height and free travel as describe later in this
section.

20
Clutch adjustment

Adjust clutch pedal height

1. Fold back the carpet below the clutch

pedal to expose the asphalt sheet
covering the floor panel.
2. Measure the distance from the center
of the pedal pad and floor panel as
shown in the illustration.
3. If the distance is not within
specifications, adjust the pedal stop
bolt until the pedal height is correct.
Check the pedal free travel.
Clutch pedal height and free travel
measuring points.
A = 5-15 mm, B = 139 mm.
https://www.howacarworks.com/basics/how-a-
car-clutch-works

Adjust clutch pedal free travel

1. Position a ruler to the side of the clutch pedal with the edge resting on the
floor panel.
2. Depress the pedal lightly by hand until resistance from the master cylinder
piston is felt and measure the pedal free travel on the ruler as shown in the
illustration. Compare the free travel to specifications.
3. If necessary, loosen the pushrod locknut and lengthen or shorten the pushrod
as necessary until the specified free travel is obtained. Tighten the locknut
securely.

POST-TEST: MULTIPLE CHOICE (10points)

Directions: Read each item carefully. Write the letter that corresponds to your
answer. Write your answers in a separate sheet.

1. Which of the following parts of the cover assembly that hold the
pressure plate against the clutch plate?
C. Lever C. Springs
D. Thrust bearings D. Struts

2. Which of the following is the coefficient of friction of the clutch plate?

C. 0.1 C. 0.8
D. 0.4 D. 1.3

21
3. What are the two types of pressure plates?
A. Coil spring C. Extension spring
B Diaphragm spring D. Torsion spring

4. What part reduces friction between clutch fork and pressure plate?
A. Clutch housing C. Pressure plate
B. Flywheel D. Throw out bearing

5. What part of the clutch system reduces friction between clutch fork
and pressure plate?
A. Clutch housing C. Pressure plate
B. Flywheel D. Throw out bearing

6. What type of clutch has a higher coefficient of friction, low pressure

plate pressure, lower clutch pedal pressure, smoother operation?
A. Ceramic/Metallic clutches C. Organic clutches
B. Multi-disc clutches D. throw out bearing

7. What part bolts to the rear of engine; encloses clutch components.

Transmission bolts to the back.
A. clutch housing C. pressure plate
B. Flywheel D. throw out bearing

8. What part bolted to crankshaft, smooth iron face, wears well and
dissipates heat
A. clutch housing C. pressure plate
B. Flywheel D. throw out bearing

9. Where is the clutch located?

A Between transmission and engine
B. Between transmission and rear axle
C. Between transmission and differential
D. Between transmission and propeller shaft

10, What point thus the clutch actually wearing?

A. At highway speeds when the vehicle is in top-gear
B. While the clutch disc and the flywheel are spinning at different
speeds
C. While the engine and the transmission are spinning at the same
speeds
D. While the engine and the transmission are spinning at the different
speeds

22
 NAME: ___________________________________________ Date ______________________
GRADE & SECTION ____________________________ Teacher: ___________________

MODULE IN AUTOMOTIVE SERVICING NCII

Grade 12
Fourth Quarter
Week 4

MOST ESSENTIAL LEARNING COMPETENCY

o Procedures in assembling manual transmission TLE_IAAUS9-12OMT-
Ie-j-45

Objectives:
1. Perform disassemble transmission parts.
2. Perform procedure in assembling transmission as per standard
operating procedures.

PRE-TEST: MULTIPLE CHOICE (10 points)

Directions: Read each item carefully. Write the letter that corresponds to your
answer. Write your answers in a separate sheet.

1. What gear connects the drive shaft in a manual transmission?

A. Belt C. Layshaft
B. Collar D. Transaxle

2. Which following part connects the manual transmission and engine?

A. Belt C. Differential
B. Clutch D. Driveshaft

3. Which type of manual transmission used the double-declutching?

A. Constant-mesh gearbox C. Sliding mesh gearbox
B. Epicyclical gearbox D. Synchromesh gearbox

4. Which types of gears are used in constant mesh gearbox?

A. Bevel gear C. Spur gear
B. Helical gear D. Worm gear

5. Why are the helical gears commonly used in transmission over spur
gears?
A. Low cost and high strength
B. Low noise level and low cost
C. Low noise level and economy
D. Low noise level and high strength

23
6. What does a tachometer used to measure?
A. The gear ratio in the transmission
B. How many miles per hour you are traveling
C. The tackiness of the engine oil and when it needs to be changed
D. How many revolutions per minute the engine crankshaft is making

7. Which of the following is the need of the gearbox?

A. To vary the power of the vehicle
B. To vary the speed of the vehicle
C. To vary the torque of the vehicle
D. To vary the acceleration of the vehicle

8. Where is the overdrive located?

A. Between transmission and engine
B. Between transmission and rear axle
C. Between transmission and differential
D. Between transmission and propeller shaft

9. How do you start a manual transmission when your battery is dead?

A. You can’t start any car when your battery is dead.
B. Roll it down a hill and release the clutch while in first gear.
C. Turn the key while the parking brake is on and you are in neutral.
D. While depressing the brake, press down on the gas pedal once and
turn the key.

10. Where is the clutch pedal located?

A. It is on the floor to the right of the gas pedal.
B. It is on the floor to the left of the brake pedal.
C. It is next to the gearshift on the center column.
D. It is on the floor between the brake pedal and the gas pedal.

24
TRANSAXLE SUBASSEMBLY ASSEMBLY PROCEDURE

Layout of the transmission output shaft

https://www.thecarconnection.com/tips-article/1088353_how-does-my-cars-
transmission-work

Service Tip:

The synchronizer sleeve has a large, deep groove located on the outside
diameter at the rear of the synchronizer assembly. The synchronizer hub
has a longer front hub than rear. When building up the synchronizer
assembly align the file marks on the sleeve and hub and place the sleeve
groove at the opposite end of the synchronizer hub from the long front hub.

1. Install the third and fourth synchronizer assembly with the longer front
inner hub facing up. The synchronizer sleeve should be facing
downward,
2. Be sure the notches on the synchronizer blocker rings align
with the inserts of the synchronizer assembly.

3. Install the third and fourth synchronizer assembly snap ring. Tap
the snap ring with a hammer and punch to ensure it is seated.

4. Turn the rear of the output shaft upward to install the remaining output
shaft parts.

25
5. Lubricate the inside diameter of the second speed gear and slide on the
output shaft with the cone clutch facing up.

6. Install the synchronizer blocker ring so the cone clutches meet.

7. Install the first and second synchronizer assemblies so the large, deep
shift fork groove is facing downward.

8. Install the first and second synchronizer snap ring making sure it is
seated the output shaft groove.

9. The first gear synchronizer blocker ring can be installed and the inserts
aligned.

10. Lubricate the inside diameter of the first speed gear and install with the
steel thrust washer and the spring washer.

11. Using a hydraulic press install the rear bearing onto the output
shaft. Install the rear bearing snap ring.

12. Install the speedometer drive gear and retaining clip.

13. With the output shaft assembled, test your assembly work

a. Check that all gears on the output shaft rotate freely.

b. Check that the synchronizer blocker rings are not jammed on the gear
cone clutches

c. Make sure all snap rings are seated into place

14. Place petroleum jelly into the socket at the rear of the transmission
input shaft and install the roller bearings.

TRANSMISSION ASSEMBLY PROCEDURE

1. Place thrust rings and washers at either end

of cluster gear assembly.

NOTE: Petroleum jelly or heavy grease

can be used to hold these parts
in place during assembly.

26
2. Insert the cluster gear assembly,
thrust rings, washers, and dummy
shaft through the rear opening of
the transmission housing. Be sure
the thrust washer tangs face away
from the cluster assembly and the
tangs index with the grooves inside
the transmission housing.

3. Align the cluster assembly with

the holes in the transmission
housing and insert the counter
shaft and woodruff key from the
rear.

4. Using a plastic hammer, tap the

counter shaft and woodruff key
into place in the transmission
housing while removing the Roller bearings being installed in the
dummy shaft. transmission input shaft using petroleum
jelly or heavy grease to hold rollers in place
.
Modern Automotive Technology 7th Edition, James Duffy,
The Goodheart-Wilcox Company, Inc., 2009. (ISBN: 978-
1-59070-956-6)
5. Lubricate the reverse idler gear inside diameter and install the s://www

reverse idler gear, shaft, and woodruff key from the rear of the
housing.

6. With snap ring pliers, expand the extension housing snap ring and
slide the extension housing over the output shaft assembly. Be sure
the snap ring seats in the rear bearing outer groove.

7. Place the fourth gear synchronizer blocker ring into place on the third
and fourth synchronizer assembly. Be sure the notches of the
synchronizer blocker ring align with the synchronizer inserts.

8. Place the transmission input shaft on the pilot (front) of the output shaft.

27
Service Tip:
9. Feed the input shaft, output shaft assembly, and extension
housing through the rear opening of the transmission housing.
10. The reverse idler might have to be moved back and forth on the shaft to
accommodate the assembly operation.
11. Align the extension housing bolt holes and install the extension
housing bolts. Do not tighten these bolts until the front
transmission bearing is installed.
12. Install the large outer front bearing snap ring over the outer bearing race.
13. Slide the front transmission bearing onto the transmission input shaft
and seat into place.
14. Install the small front transmission bearing snap ring.
15. Align the front bearing retainer and gasket to the transmission housing.
Be sure the lubricant drainage groove aligns with the transmission
housing. Install the front bearing retainer bolts.
16. Tighten extension housing to transmission housing bolts.
17. Move all synchronizer sleeves to the neutral position.
18. Place the transmission cover gasket in place.
19. Shift the forks on the cover plate to the neutral position.
20. Install the cover plate with the shift forks seating into the synchronizer
sleeves and tighten all bolts.
21. The transmission should be shifted through all gear ranges
before installing into the vehicle.

28
POST-TEST: MULTIPLE CHOICE (10 points)
Directions: Read each item carefully. Write the letter that corresponds to your
answer. Write your answers in a separate sheet.

1. A manual transmission is connected to the engine through the:

A. Belt C. Differential
B. Clutch D. Driveshaft

2. What connects the gears to the drive shaft in a manual transmission?

A. Belt C. Layshaft
B. Collar D. Transaxle

3. Which type of manual transmission used the double-declutching?

A. Constant-mesh gearbox C. Sliding mesh gearbox
B. Epicyclical gearbox D. Synchromesh gearbox

4. Which types of gears are used in constant mesh gearbox?

A. Bevel gear C. Spur gear
B. Helical gear D. Worm gear

5. Why are the helical gears used commonly in transmission over spur
gears?
A. Low cost and high strength
B. Low noise level and low cost
C. Low noise level and economy
D. Low noise level and high strength

6. Which of the following is the need of the gearbox?

A. To vary the power of the vehicle
B. To vary the speed of the vehicle
C. To vary the torque of the vehicle
D. To vary the acceleration of the vehicle

7. What does a tachometer measure?

A. The gear ratio in the transmission
B. How many miles per hour you are traveling
C. The tackiness of the engine oil and when it needs to be changed
D. How many revolutions per minute the engine crankshaft is making

8. Where is the overdrive located?

A. Between transmission and engine

29
 B. Between transmission and rear axle
C. Between transmission and differential
D. Between transmission and propeller shaft

9. Where is the clutch pedal located?

A. It is on the floor to the right of the gas pedal
B. It is on the floor to the left of the brake pedal
C. It is next to the gearshift on the center column
D. It is on the floor between the brake pedal and the gas pedal

10. How do you start a manual transmission when your battery is dead?
A. You can’t start any car when your battery is dead.
B. Roll it down a hill and release the clutch while in first gear.
C. Turn the key while the parking brake is on and you are in neutral.
D. While depressing the brake, press down on the gas pedal once and
turn the key.

30
 REFERENCES:

Modern Automotive Technology Seventh Edition, James E. Duffy, The Goodheart

Willcox Company, Inc., 2009. (ISBN 978-1-59070-956-6)

Automotive Technology, A systems Approach Fourth Edition, Jack Erjavec, The

Thomson-Delmar Learning Company, Inc., 2005. (ISBN 1-4018-4831-1)

Diesel Technology Seventh Edition, Andrew Norman and John “Drew”

Corinchock, The Goodheart-Wilcox Company, Inc., 2007. (ISBN-13: 978-1-
59070-770-8)

Carburetor Service Manual. Ford Marketing Corporation Autolite-Ford Parts

Division, National Service Department.

Engine Performance Evaluation with 1972 Emission Control Systems.

Stock Code No. TMH-104. Detroit, Michigan: Chrysler Motor
Corporation, Service Department.

Motors Auto Repair Manual. 27th ed. New York: Motor Magazine,
1964. Pp. 1280.

Stockel, Martin W. Auto Mechanics Fundamentals. Chicago:

Goodheart-Wilcox Company, Inc., 1969. Pp. 480.

Vehicle Emission Control Manual. Washington, D. C.: Division

of Manpower, U. S. Office of Education.

Medium/Heavy Duty Truck Engines, Fuel & Computerized Management

Systems 2nd Edition, Sean Bennett, The Thomson/Delmar Learning Company,
INC., 2004. (ISBN13:978-1-4018-1499-1)

Heavy Duty Truck Systems 4th Edition, Sean Bennet, Delmar Cengage Learning,
2006. (ISBN-13:978-1-4018-7064-5)

Modern Automotive Technology 7th Edition, James Duffy, The Goodheart-Wilcox

Company, Inc., 2009. (ISBN: 978-1-59070-956-6)

Automatic Transmissions and Transaxles, James Duffy, The Goodheart-Wilcox

Company, Inc., 2005. (ISBN: 1-59070-426-6)

Manual Drive Trains and Axles, Chris Johanson, James Duffy, The Goodheart-
Wilcox Company, Inc., 2004. (ISBN: 1-59070-320-0)

31
 32
Week 4- Week 4- Week 3- Week 3-
Post-Test Pre-Test Post-Test Pre-Test
1B 1D 1C 1B
2D 2B 2C 2B
3D 3D 3B 3D
4B 4B 4B 4D
5D 5D 5A 5C
6C 6D 6B 6B
7D 7C 7D 7B
8D 8D 8C 8C
9B 9B 9A 9A
10 B 10 B 10 C 10 C
Week 2- Week 2- Week 1- Week 1-
Post-Test Pre-Test Post-Test Pre-Test
1C 1A 1C 1D
2D 2A 2D 2C
3A 3C 3D 3D
4A 4D 4D 4D
5C 5B 5D 5A
6C 6B 6A 6D
7D 7D 7A 7D
8B 8B 8B 8C
9B 9B 9A 9B
10 A 10 A 10 B 10 B
ANSWER KEY: