ashok layland
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Ashok Leyland
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Ashok Leyland
Ashok Leyland is an Indian automobile manufacturing company based in Chennai, India.
Founded in 1948, it is the 2nd largest commercial vehicle manufacturer in India, 4th largest
manufacturer of buses in the orld and 1!th largest manufacturer of truc"s globally. #perating
si$ plants, %sho" &eyland also ma"es spare parts and engines for industrial and marineapplications. It sells about !',''' vehicles and about (,''' engines annually. It is the second
largest commercial vehicle company in India in the medium and heavy commercial vehicle
)*+C- segment ith a mar"et share of 28/ )2''(0'8. ith passenger transportation
options ranging from 19 seaters to 8' seaters, %sho" &eyland is a mar"et leader in the bus
segment. he company claims to carry more than !' million passengers a day, more people than
the entire Indian rail netor". In the truc"s segment %sho" &eyland primarily concentrates on
the 1! ton to 23 ton range of truc"s. oever %sho" &eyland has presence in the entire truc"
range starting from (.3 tons to 49 tons. ith a oint venture ith 5issan *otors of 6apan the
company made its presence in the &ight Commercial -ehicle )&C- segment )7(.3 tons.
%sho" &eylands : subsidiary #ptare has shut don its bus factory in ;lac"burn, &ancashire.
his subsidiarys traditional home in &eeds has also been vacated in favour of a purpose built
plant at ?herburn@in@Almet.
HISTORY
ASHOK MOTORS
%sho" *otors as founded in 1948 by Baghunandan ?aran, an Indian freedom fighter from
unab. %fter Independence, he as persuaded by IndiaDs first rime *inister 5ehru, to invest
in modern industrial venture. %sho" *otors as incorporated in 1948 as a company to assemble
and manufacture %ustin cars from Angland, and the company as named after the founders only
son %sho" ?aran. he company had its headEuarters in Baai ?aalai, Chennai )then *adras
ith the plant in Annore, a small fishing hamlet in the 5orth of Chennai. he Company as
engaged in assembly and distribution of %ustin %4' passenger cars in India.
UNDER LEYLAND
?ometime later, Baghunandan ?aran died in an air crash, prior to that he had been negotiating
ith &eyland *otors of Angland for assembly of commercial vehicles as he envisioned
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commercial vehicle ere more in need at that time than ere passenger cars. he company later
under *adras ?tate overnment and other shareholders finalised for an investment and
technology partner and thus &eyland *otors oined in 1934 ith eEuity participation, changing
the name of the company to %sho" &eyland. %sho" &eyland then started manufacturing
commercial vehicles. nder &eylands management ith ;ritish e$patriate and Indian e$ecutives
the company gre in strength to become one of Indias foremost commercial vehicle
manufacturers.
he collaboration ended sometime in 19(3 but the holding of ;ritish &eyland, no a maor
;ritish %uto Conglomerate as a result of several mergers agreed to assist in technology hich
continued until the 198's. ost 19(3, changes in management structures sa the company launch
various advanced vehicles and pioneering innovations in the Indian mar"et, ith many of these
models continuing to this day ith numerous upgrades over the years.
PRODUCT RANGE OF THE COMPANY INCLUDES:
• ;uses
• ruc"s
• Angines
• Gefence + ?pecial -ehicles
ASSOCIATES COMPANIES:
• %utomotive Coaches + Components &td )%CC&
• &an"a %sho" &eyland
• indua Foundries
• IBIH%B0-?
• %sho" &eyland roect ?ervices &imited
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• Aa!ds"A#h$e%e&en's
• In the ourney toards global standards of Euality, %sho" &eyland reached a maor
milestone in 199= hen it became the first in Indias automobile history to in the I?#
9''2 certification. he more comprehensive I?# 9''1 certification came in 1994, ?
9''' in 1998 and I?# 14''1 certification for all vehicle manufacturing units in 2''2. It
has also become the first Indian auto company to receive the latest I?#J? 1!949
Corporate Certification )in 6uly 2''! hich is specific to the auto industry.
• DIRECTORS( REPORT
• Pe!)o!&an#e " O*e!a'$ons
• he Girectors have pleasure in presenting the %nnual Beport of the Company, together
ith the financial statements, for the year ended *arch =1, 2'13.
• Co&*any Pe!)o!&an#e
• Guring the year under revie, your Company itnessed a modest recovery in the Indian
economy, enabling the *edium + eavy Commercial -ehicle )*+C- industry to
signal an uptrend after to years of don cycle. hilst overall commercial vehicle
volumes declined by 2.8/ over the previous year, the *+C- segment volumes
increased by 1!/. Kour Company improved its mar"et share from 2!.1/ to 28.!/ in the
*+C- segment, facilitated by appropriate product mi$ in the groth segments, a
sustained focus on meeting customer reEuirements and initiatives in netor" e$pansion.
*+C- e$port volumes gre by =1.(/ to 11,218 units from 8,311 units last year,
enabled by groth in target e$port mar"ets.
• In the &ight Commercial -ehicle segment, the industry volumes contracted by 1=.4/.
oever, your Company has been able to sustain the mar"et share in the small
Commercial -ehicle )20=.3 segment supported by sustained product improvements and
variants on G#?, hich is the 2nd largest player in the segment. he ne %B5AB
range of products has also achieved significant mar"et share in the !0(.3 segment, its
first full year after launch.
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• oer ?olutions ;usiness continued to have subdued demand due to improved poer
availability and slodon in Industrial J %gricultural segments. he ?pare arts volumes
have bounced bac" due to higher demand and focused actions at improving parts
availability and competitiveness. ighlights of performance are discussed in detail in the
*anagement Giscussion and %nalysis Beport attached as Anne+,!e-D to this Beport.
• DI.IDEND
• he Girectors recommend a dividend of 43/ )Bs. '.43 per eEuity share of Bs. 1J0 each
for the financial year ended *arch =1, 2'13. ayment of dividend is subect to the
approval of shareholders at the ensuing %nnual eneral *eeting.
• FUND RAISING
• E/UITY - /UALIFIED INSTITUTIONAL PLACEMENT
• Guring the year under revie, your Company successfully placed 183,2'',''' eEuity
shares through the process of ualified Institutional lacement )I and raised an
amount of Bs. !!!.(2 crore. he proceeds received through I ere utilised for the
purpose for hich it as raised. ConseEuent to the above, the paid up value of the eEuity
share capital of the Company stands increased from Bs. 2!!.'( crore to Bs. 284.39 crore.
• DE0T
• Se#,!ed Non-Con%e!'$1le De1en',!es 2NCD3
• Guring the year, your Company redeemed in full 5CG ?eries %& 14 placed in 6uly 2'1'
amounting to Bs. (' crore. 5o fresh 5CGs ere issued during the year.
• R,*ee Te!& Loans
• Kour Company has repaid or prepaid ?ecured Bupee erm &oan availed from ;an"s to
the tune of Bs. 43' crore during the year. 5o fresh erm &oan as availed during the
year.
• E4TERNAL COMMERCIAL 0ORRO5INGS 2EC0S3
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• Guring the year under revie, your Company repaid AC; loan instalments that fell due,
eEuivalent to ?G (1.!! *n. Kour Company availed fresh AC;s for ?G 2' *n, from
a ;an" for an average tenor of 3 years on unsecured basis. he funds dran under AC;s
ere utilised to fund capital e$penditure program of the Company and other approved
end uses as per e$tant Beserve ;an" of India uidelines and the terms of the loan. %s at
*arch =1, 2'13, long term borroings stood at Bs. =,=23 crore as against Bs. 4,1'= croreon *arch =1, 2'14.
In'!od,#'$on 'o En6$ne Re*a$! - S',dy G,$de
In'!od,#'$on
he engine is the poer plant of a vehicle. %utomotive engines have gone through tremendous
changes since the automobile as first introduced in the 188's, but all combustion engines still
have three reEuirements that must be met to do their ob of providing poer 0 air, fuel, and
ignition. he mi$ture of air and fuel must be compressed inside the engine in order to ma"e it
highly combustible and get the most out of the energy contained in the fuel mi$ture. ?ince the
mi$ture is ignited ithin the engine, automobile poer plants are called $n'e!nal #o&1,s'$on
engines. *ost can be further classified as !e#$*!o#a'$n6 *$s'on engines, since pistons move up
and don ithin cylinders to provide poer. his up@and@don motion is converted into turning
motion by the cran"shaft.
Some of the main engine components
his course ill provide an introduction
to automotive engines and engine repair.
?ubects covered ill includeL
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M *aor engine components
M Angine classifications
M he four stro"e cycle and other
engine design operations
M Angine construction
M eneral engine mechanical diagnosis
M Angine removal and installation
M Cylinder head and valve train diagnosis and repair
M Angine bloc" assembly diagnosis and repair
Un$' 7 8 0as$# En6$ne Pa!'s
and O*e!a'$on
Un$' O19e#'$%e:
%fter completion of this unit, students
should be able to identify internal
combustion engine components and their
modes of operation.
S*e#$)$# O19e#'$%es:
M Identify engine design
associated terms and definitions
M Identify internal combustion engine components
M nderstand and be able to e$plain basic internal combustion engine operation
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M Identify common internal combustion engine design classifications
% small engine, such as one found in a lan moer, usually contains only
one cylinder and piston. %utomotive engines use a number of cylinders to
produce sufficient poer to drive the heels, but operate much li"e a
small engine in many ays. &etDs loo" at one cylinder of an engine to see
ho the main parts or" together.
En6$ne 0lo#k
he bloc", highlighted at right in grey, is a heavy metal casting, usually
cast iron or aluminum, hich holds the loer parts of the engine together
and in place. he bloc" assembly consists of the 1lo#k , #!anksha)',
&a$n 1ea!$n6s and
#a*s #onne#'$n6 !ods,
*$s'ons, and other
components, and is
referred to as the
1o''o& end. he bloc"
may also house the
camshaft, oil pump,
and other parts. he
bloc" is machined ith
passages for oil
circulation called o$l
6alle!$es )not shon
and for coolant
circulation called
a'e! 9a#ke's.
Cyl$nde!s
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he cylinders are round holes or 1o!es machined into the bloc" for the pistons to travel up and
don in.
P$s'ons
Combustion pressure acts upon the tops of the pistons in the cylinders, forcing them donard.
sually made of aluminum, the pistons transmit the donard force to the connecting rods.
he top of the pistonDs travel is called op Gead Center )GC and the bottom of a pistonDs
travel is called ;ottom Gead Center );GC.
P$s'on R$n6s
Bings are installed in grooves around the pistons to form a seal beteen the piston and the
cylinder all. o types of rings are usedL #o&*!ess$on !$n6s, hich prevent combustion
pressure from entering the cran"case, and o$l #on'!ol !$n6s, hich prevent engine oil from
entering the #o&1,s'$on #ha&1e! above the piston. #il rings scrape e$cess oil from the
cylinder alls for return to the cran"case.
Cylinde Piston Connecting Rod
Conne#'$n6 Rods
% rod connects each piston to the cran"shaft. he small, upper end of the rod commonly has a
bushing pressed into it. %*$s'on *$n, or !$s' *$n, attaches the piston to the rod through this
bushing, hich allos the rod to pivot as needed. he larger, loer end of the rod is attached to
the cran"shaft through !od 1ea!$n6 $nse!'s that are stationary relative to the rod and allo the
cran"shaft to turn ithin the rod on a film of oil.
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C!anksha)'
he cran"shaft is a strong, alloyed iron or steel shaft that converts
the up@and@don motion of the pistons into a turning motion that
can be transmitted to the drive train. he cran"shaft is supported
by the bloc" in several places along its length. he cran"shaft rides
in &a$n 1ea!$n6s, hich are inserts similar to the rod bearings at
these supports. here the cran"shaft is connected to the rods and
here it is supported by the bloc" are called 9o,!nals. he cran" is
finely machined and polished at these places. he cran"shaft is
also drilled ith a netor" of oil passages to deliver oil under
pressure to these places from the oil galleries. Co,n'e!e$6h's are
formed onto the cran"shaft to help prevent vibration.
hese eights are added to offset the eight of the piston and
connecting rod assemblies. %t the front of the cran"shaft, outside
the engine front cover, a heavy heel containing a rubber vibration
damper is installed. %lso called a ha!&on$# 1alan#e!, it often
incorporates the cran" drive belt pulley, hich poers belt@ driven
accessories. %t the rear of the cran"shaft, a large )lyheel is
mounted. he flyheel can serve several purposesL a ring gear is
mounted to its circumference to provide a means to start the
engine. It also connects the engine to the transmission. Finally, on
vehicles ith manual transmissions, the flyheel is made very
heavy to help smooth out poer pulses from the engine )this is
accomplished by the torEue converter on vehicles eEuipped ith
automatic transmissions.
Cyl$nde! Head
&i"e the engine bloc", cylinder heads are usually cast
from either iron or aluminum. *ost -@type, opposed, and
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@type engines have to cylinder heads. Inline engines
have only one cylinder head. he head bolts to the top of
the bloc", covering and enclosing the tops of the
cylinders. he head forms small poc"ets over the tops of
the pistons called #o&1,s'$on #ha&1e!s. he s*a!k
*l,6s are threaded into holes in the head and protrude
into the combustion chambers )gasoline engines. In'ake
*o!'s and e+ha,s' *o!'s are cast into the head, and small
holes called %al%e 6,$des are machined into it to position
the valves. he %al%es act as gates. hen open, they let
air and fuel into the cylinder and e$haust gas out. hen
closed, they seal the
pressure of compression in the combustion chamber. he
valves close against machined, press@fitted inserts in the
combustion chamber ports called %al%e sea's. #n
overhead cam engines li"e the one pictured here, the
head also houses the #a&sha)'. he assembly, together
ith other valve train components and the inta"e and
e$haust manifolds, is referred to as the 'o* end.
;eteen the head and the bloc", a head 6aske' seals the
combustion chambers, and ater and oil passages.
Cyl$nde! Head
.al%e T!a$n
he valve train consists of the %al%es, #a&sha)', and
other associated parts. he valves control the flo of theincoming air@fuel mi$ture and the outgoing e$haust
gasses. he $n'ake %al%es are larger than the e+ha,s'
%al%es, and many engines today have to inta"e and
to e$haust valves per cylinder to improve efficiency
and performance.&i"e the cran"shaft, the camshaft rides
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on a film of oil as it rotates on ournals. Botation of the
camshaft opens the valves, and %al%e s*!$n6s close
them. he camshaft has carefully machined high spots
called lo1es that act upon the valves )or other parts to
open each valve at precisely the right time. %s the lobe
moves aay, the spring closes the valve. ?ome engines
have dual overhead cams )G#C, ith a cam for the
inta"e valves and one for the e$haust valves. he engine
shon here uses a single overhead cam )?#C.
Angines ith the camshaft located in the
bloc" are called *,sh!od en6$nes, because
long pushrods are used to transmit the
camshaftDs movement up to the !o#ke!
a!&s, hich roc" to open the valves. #n
these engines, the cam acts on a valve
lifter, hich in turn acts on a pushrod to
move the roc"er arm and open the valve.
e ill e$amine this arrangement later.
#verhead cam engines may have a set of
parts called valve folloers, hich operate
li"e lifters. ?ome engines have a gear on
the camshaft to drive the ignition
distributor and oil pump, and some diesel
engines and older gasoline engines have a
rounded lobe on the camshaft to drive a
mechanical fuel pump.he engine top end
and bottom end must be timed together so
that the valves ill open and close at the
proper times for the positions of the
pistons, and this is accomplished through
the camshaft drive. he camshaft is driven
by a Timing Gears and Belt Valve Train
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sproc"et gear mounted on the front of the
cran"shaft.
he sproc"et either meshes ith a sproc"et on the front of the camshaft, or, more often, the to
sproc"ets are lin"ed by a belt or a chain. In the engine shon here, '$&$n6 6ea!s and a '$&$n6
1el' are used. ;oth sproc"ets must be installed ith their timing mar"s aligned in the proper
positions in order to time the engine.
The Fo,!8S'!oke Cy#le 2O''o Cy#le3
% s'!oke is one movement of the piston either don from op Gead Center )GC to ;ottom
Gead Center );GC, or up from ;GC to
GC. he term Nstro"eO also refers to the physical distance beteen these to points. #ne
stro"e of the piston moves the cran"shaft through one@half of a revolution. %lmost all
engines on the road today operate on a cycle of four piston stro"es. he stro"es are the
$n'ake s'!oke, #o&*!ess$on s'!oke, *oe! s'!oke, and the e+ha,s' s'!oke. his cycle turns
the cran"shaft through to revolutions and then the process begins again.
In'ake S'!oke
he process begins ith the inta"e stro"e. he piston moves don from top dead center )GC
to bottom dead center );GC. he movement of the piston creates a partial vacuum, draing air
and fuel into the cylinder through the open inta"e valve. he ideal air@fuel mi$ture for
performance, economy and emission control is 14.( parts air to 1 part fuel. #n hrottle ;ody
fuel Inection );I systems and old carbureted systems, fuel is carried in the air stream through
an inta"e manifold and into the inta"e port. #n *ultiport Fuel Inection )*FI systems, each
cylinder has its on inector, hich allos fuel to be inected into the port ith more precision
and uniformity than possible ith hrottle ;ody systems. Guring this stro"e, the e$haust valveremains closed.
Co&*!ess$on S'!oke
%fter the piston passes ;GC, the compression stro"e begins. he inta"e valve closes and the
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mi$ture in the cylinder is compressed by the piston as it moves upard again to GC. he
inta"e and e$haust valves are both closed during this stro"e, so the pressure and temperature of
the air@fuel mi$ture rises. % typical compression ratio for a gasoline engine might be 9L1. he
compression ratio is the volume of the cylinder, including the combustion chamber, ith the
piston at ;GC compared to the volume ith the piston at GC. he cran"shaft has no made
one revolution.
Poe! S'!oke
his is hat itDs all aboutP %s the piston nears GC ith both valves closed, the compressed air@
fuel mi$ture is ignited. Combustion occurs, resulting in a tremendous pressure increase that
pushes the piston bac" don the cylinder. his is the poer or Nor"ingO stro"e. he inta"e and
e$haust valves remain closed. In an idling engine, this happens in each cylinder about five times
a second and running at 4,''' B* it happens over =' times a secondP
E+ha,s' S'!oke
5o, the spent gasses must be removed from the cylinder to ma"e room for the ne$t air@fuel
charge. he e$haust stro"e begins as the piston nears ;GC. he e$haust valve opens and the
piston moves upard again, pushing the burned e$haust gases out of the cylinder. he inta"e
valve remains closed until the piston has almost reached GC again. %t this point, the engine
has completed one full cycle, and the cran"shaft has rotated tice. he entire process then
repeats.
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Intake Compression Power Eha!st
O'he! En6$ne Des$6ns
hile the vast maority of automobile engines are gasoline@ poered, four@stro"e reciprocating
piston engines, other engine designs have been developed and used in automobiles, some Euite
successfully. %dditionally, changing economic, environmental, and political conditions have
created a demand to modify or retire this proven or"horse ith ne or re@or"ed designs. %s
materials and technologies improve and evolve, some of these contenders may come into
common use in automobiles.
To8S'!oke Cy#le En6$nes
% to @stro"e cycle engine is another reciprocating piston design. Avery donstro"e delivers
poer in this design, and it has no valve train. Instead, in a conventional to@stro"e gasoline
engine, the air@fuel and e$haust gas are managed by the piston as it covers and uncovers inta"e
and e$haust ports in the side of the cylinder. It also has no oil sump or pressuriQed oil delivery
system, because the cran"case is part of the fuel delivery system. Instead, the cran"case is
lubricated by mi$ing a small amount of oil ith the fuel. ;eing able to deliver poer ith every
don stro"e and not having a heavy valve train means the to@stro"e engine can provide a lot of
poer for its siQe and eight. o@stro"e engines have been used for many years in small engine
applications such as outboard boat engines, motorcycles, ultralight aircraft, chainsas and lan
eEuipment, etc. ?ome to@stro"e engine automobiles have been imported to the .?., and many
medium and heavy duty diesel applications are currently eEuipped ith to@stro"e engines.
nfortunately, the light eight and simplicity come at a price. Conventional to@stro"e
gasoline engines produce higher e$haust emissions and yield loer fuel economy than a
comparable four@stro"e engine. his is largely due to the burning of the oil in the
combustion chamber and lea"age of unburned fuel inherent in the engineDs design. he causes
of this ill be clearer hen e e$amine the operation of the engine. 5evertheless, the to@
stro"e engine has received reneed interest in recent years, as innovations and advancements in
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fuel inection, materials, and engine management systems develop. hese engines have a
pressuriQed lubrication system, fuel inectors, and superchargers that compress the inta"e air,
similar to a to@stro"e diesel engine.
The To8S'!oke Cy#le
eDll begin the e$planation of the to@stro"e cycle ith thefiring of the spar" plug, hichoccurs before every donstro"e. %s the piston moves don, delivering poer, the inta"e and
e$haust ports are both covered. %t the same time, the donard movement of the piston is
pressuriQing the cran"case ith the ne$t air@fuel charge, hich as dran into the cran"case
through the air@fuel inlet and around the reed valve. his pressure forces the reed valve to close.
%s the piston continues donard, it uncovers the e$haust port. Bemaining combustion pressure
begins to blo the spent gas out the port. Further donard movement uncovers the inta"e port
as ell, and both ports are open for an instant, as the pressuriQed air@fuel charge from the
cran"case enters the cylinder. he incoming air@fuel purges the remaining e$haust gas from the
cylinder. %s the piston travels upard again, it covers the inta"e and e$haust ports so
compression can begin. %t the same time, the pistonDs movement creates a vacuum in the
cran"case, opening the reed valve again and draing in the ne$t air@fuel charge.
End of !p stroke "ear end of down stroke
D$esel En6$nes
he diesel engine is another reciprocating piston
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design. Giesel engines in passenger cars and light
truc"s operate on the four@stro"e cycle, but they
have important differences from the gasoline
engines e have discussed. he most significant
difference is the ay in hich diesel engines ignite
the fuel. Bather than using a spar" to start the
combustion, a diesel engine uses the heat produced
by compression of the air in the cylinder. Giesel
engines must compress the air much more than a
gasoline engine does 0 about tice as much 0 in
order to produce enough heat to ignite the fuel.
Co&*!ess$on $6n$'$on engines such as diesels must
be designed heavier and stronger than s*a!k
$6n$'$on engines to ithstand the compression and
combustion produced in the cylinders. hese
engines have steel sleeves pressed into their
cylinder bores.
Unde!s'and$n6 0!akes L %ir bra"e systems are used on heavy truc"s for safety, efficiency and
reliability. #ne maor advantage to an air bra"e system is that since air never runs out, the air
bra"e system can alays be replenished. %n air bra"e system is marginally functional even
ith a small lea". ;ut donDt read that asR it is safe to drive your mi$er ith an air lea".
Th!ee $n OneL he air bra"e system is actually three separate
systems @ ?ervice ;ra"e, ar"ing ;ra"e and Amergency
;ra"e. he various components of an air bra"e system or"
together to create and maintain a supply of compressed air and
convert air pressure energy into mechanical force.
Se!%$#e 0!ake: his system applies and releases the )service
bra"es hen the driver pushesJreleases the
bra"e pedal. ushing the bra"e pedal, opens a valve to let air flo from the air tan" through
the airlines to a bra"e chamber. his air forces a pushrod out, hich in turn pushes a slac"
aduster, turning the camshaft, tisting the ?@Cam forcing the bra"e linings to ma"e contact
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ith the bra"e drum. his causes friction, hich slos the vehicle. #ne drabac" to air bra"es
is bra"e lag, hich is the time reEuired for air to flo through the lines and force the
engagement of the linings to the drum. hough the travel time is less than a second, air bra"es
do not apply immediately after the driver pushes the bra"e pedal, as they do in a car.
Pa!k$n6 0!ake: o par" the vehicle, a driver applies the spring bra"es by pulling out the
yello valve on the dash. his releases air from the bra"e chamber hich allos the bra"e
spring to e$pand and forces the pushrod out hich pushes a slac" aduster that turns the
camshaft, tisting the ?@Cam and forcing the bra"e linings against the bra"e drum.
E&e!6en#y 0!ake bra"es are held off by air pressure inside the bra"e chamber, hich holds
bac" a very poerful spring. hen there is insufficient air in the system to "eep the spring in
the chamber restrained, the emergency bra"es automatically engage. hen air pressure falls
belo !' psi, a lo pressure arning light ill come on along ith an audible buQQer. If air
pressure continues to fall, the emergency bra"e ill automatically apply hen air pressure
drops to 2'@43psi.
he fail safe engineering of air bra"es ill not allo you to control activation of the
emergency bra"e so loo" for a safe place to pull off the roaday as soon as the lo pressure
arning activates.
Cylinder Head Diagnosis and Repair
On8Ca! .al%e Seal Re*la#e&en'
%s mentioned earlier in this course, many technicians ill replace valve seals on high@
mileage engines in response to customer complaints of oil consumption andJor visible smo"e
out of the tailpipe. his is a short@term repair in many cases. Beplacing the valve seals does
not recondition the cylinder head, and may not solve the oil consumption problem long@term.
M Man,)a#',!e!;s s*e#$)$# *,1l$shed se!%$#e *!o#ed,!es de'a$l$n6 #o&*onen' and
)as'ene! !e&o%al o! $ns'alla'$on se
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1. Gisconnect the negative battery cable.
2. Bemove the engine accessories necessary for valve cover removal.
=. Bemove the valve cover)s.
4. Bemove the valve train components )e.g., roc"er arms, camshafts necessary to gain
access to the valve springs.
3. Bemove the spar" plugs.
!. Insert an air hose adapter into the spar" plug opening for the cylinder being serviced.
(. Connect the shop air hose to the adapter and pressuriQe the cylinder.
8. se a valve spring compressor to compress the valve spring.
The!e a!e as &any d$))e!en' des$6ns o) %al%e s*!$n6 #o&*!esso!s as 'he!e a!e
%al%e'!a$n des$6ns= 0e s,!e 'o ,se 'he !$6h' #o&*!esso! )o! 'he en6$ne yo,;!e
o!k$n6 on 'o &$n$&$>e 'he *oss$1$l$'y o) $n9,!y o! da&a6e=
9. Bemove the valve loc"s, retainers, and spring )?ee image.
A &a6ne' $ll 1e handy he!e 'o !e&o%e and #a*',!e 'he %al%e lo#ks= 0e #a!e),l no'
'o d!o* 'he& on#e 'hey ha%e 1een !e&o%ed=
1'. Bemove the old valve stem seal.
11. Inspect the valve loc"s, valve loc" grooves, and the valve
stem and tip for signs of ear or damage.
12. Inspect the valve springs for sEuareness and signs of ear or
damage. *easure their free height. o do this, stand all of the
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springs on a flat surface ne$t to each other. hey should stand
the same height and should stand sEuarely. If there is any
discrepancy in their height or if any of the springs do not stand
sEuarely, replace all of the springs.
The 'ens$on o) ea#h %al%e s*!$n6 #an 1e 'es'ed ,s$n6 a
s*e#$al 6a,6e= E+'ens$%e 'es'$n6 o) %al%e s*!$n6s $s
6ene!ally no' #os' e))e#'$%e= In &os' #ases $' $s #hea*e! 'o
!e*la#e
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da&a6ed %al%e lo#ks $ll #a,se &a9o! en6$ne da&a6e hen
'he a))e#'ed %al%e )alls $n'o 'he #yl$nde! and #oll$des $'h
'he &o%$n6 *$s'on h$le 'he en6$ne $s !,nn$n6
1!. Bepeat these steps for each valve assembly.
1(. Beinstall the valve train components and valve cover)s.
18. Beinstall the spar" plugs and ires.
19. Beinstall the engine accessories and connect the negative battery cable.
2'. Connect the e$haust ventilation eEuipment.
0e s,!e 'o ,se a**!o%ed e+ha,s' %en'$la'$on e
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If the head is to be resurfaced or reconditioned, it should be partially disassembled once it has
been removed from the engine. ;olt@on parts, li"e the inta"e and e$haust manifolds, thermostat
housing, roc"er shaft or camshaft, spar" plugs, glo plugs, fuel inectors and the li"e should be
removed at this time if they ere not removed hile pulling the head off.
M 5hen !e&o%$n6 o! !e$ns'all$n6 'hese *a!'s )ollo &an,)a#',!e!;s s*e#$)$#
*,1l$shed se!%$#e $n)o!&a'$on and $ns'!,#'$ons )o! 'he %eh$#le 'ha' yo,;!e
o!k$n6 on=
M Man,)a#',!e!;s s*e#$)$# se!%$#e *!o#ed,!es de'a$l$n6 #o&*onen' and )as'ene!
!e&o%al o! $ns'alla'$on se
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s,!)a#es as *!e%$o,sly d$s#,ssed= Clean$n6 6aske' s,!)a#es $'h s,!)a#e #ond$'$on$n6
d$sks $s NOT !e#o&&ended 1y %eh$#le &an,)a#',!e!s=
Cyl$nde! Head Ins*e#'$on
:noing the specific customer complaint )as discussed earlier can help you find hat
youDre loo"ing for hen inspecting the cylinder head.
For e$ample, cooling system concerns, li"e overheating and loss of engine coolant, can in
many cases be traced to a arped or crac"ed cylinder head. #il consumption complaints can
sometimes be traced to orn valves and guides. *isfire and poer loss complaints are
sometimes caused by burned valves that cannot "eep the pressure of combustion confined to
the inside of the cylinder.
In addition, you may find that in some cases that replacing crac"ed, orn, or high@mileage
cylinder heads ith ne or reconditioned heads ma"es the most economic sense for the vehicle
oner.
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5a!*a6e Che#k
Chec" the head gas"et surface for arpage
using a *!e#$s$on s'!a$6h'ed6e and a set of
thin )eele! 6a,6es. Chec" the head gas"et
surface lengthise and crossise in several places.
%s a general guideline, arpage lengthise
should not measure more than .''= in. )'.'(!
mm for a three cylinder )-! head, .''4 in.
)'.1'2 mm for a four cylinder or -8 head, or
.''! in. )'.132 mm for a straight si$ head.
hen measuring side@to@side, the ma$imum
alloable limit for arpage for any head is .
''2 in. ).'3 mm
M Man,)a#',!e!;s s*e#$)$#
s*e#$)$#a'$ons )o! a!*a6e sho,ld
1e )olloed 'o 'he le''e!= The
)$6,!es 6$%en he!e a!e 6ene!al
6,$del$nes=
If a cylinder head is arped, it should be
straightened before any other machine or"
is done. his is typically a ob that most
shops ill sublet out to an automotive
machine shop.
?ome heads can be milled )shaved don to ma"e the gas"et sealing surfaces flat and true again.
#verhead cam cylinder heads are sometimes straightened by bolting the head don over shims
to a straightening fi$ture. he head and fi$ture are then heated in an oven to 43' to 3'' deg. F
)2=' to 2!' deg. C for three to si$ hours. he assembly is then cooled sloly to Nde@stressO the
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GENRAL SERI.ES STEPS :8
E&*'y$n6 o) #o&*onen's
Components should be emptied as much as possible before dismantling commences.
?ome drain locations may become easier to access later during the or".
?ee belo for the components that are involved, although these are not in any particular order.
For more detailed information and or"ing instructions refer to the other service information
in the respective groups from 1 to 9.
Fluids and chemicals shall be handled, separated and stored in a suitable ay and in
accordance ith local legislation and regulations.
En6$ne o$l and )$l'e!s
Grain the engine oil through the drain plug )%.
Bemove the engine filtersR the full flo filter ); and bypass filter )C.
Man,al 6ea!1o+ o$l and )$l'e!
Grain and empty the gearbo$ oil through the drain plug
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nscre the oil filter housing and remove the seal and oil filter.
Gea!1o+ $'h #o&*a#' !e'a!de! o$l )$l'e!
Bemove the oil filter ) from the oil filter housing.
Cover )G, gas"et )A, adapter )F and stay tube ).
F 6ea!1o+ o$l
A,'o&a'$# 6ea!1o+ o$l and )$l'e!
Grain the oil by removing the oil sump drain plug
);, and unscre the oil filters )%.
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F$nal d!$%e o$l
opping@up and drain plugs )% and );.
F$nal d!$%e $'h h,1 !ed,#'$on o$l
opping@up and drain plugs )% and ;.
he oil in the hub shall be drained separately.
Re'a!de! o$l
Grain plug )G, topping@up plug )%, vent plug )A.
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T!ans)e! 6ea!1o+ o$l
Grain plug )C, topping@up plug );, level plug )%.
Poe! 'ake8o)) o$l d!a$n$n6 and )$l'e! !e&o%al
Grain plug );, levelJtopping@up plug )%.
5a'e! se*a!a'o! )$l'e!
Bemove the filter.
D!$%en )!on' a+le o$l
Front a$le heel gears. Grain plug )%,
levelJtopping@up plug );.
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Front a$le differential carrier. Grain plug );.
U!ea 'ank
Bemove the filler cap from the urea
tan". Bemove the drain plug. Ampty
the urea tan".
No'e: If urea solution comes into contact
ith disconnected electrical connectors,
the urea solution spreads rapidly through
the iring and o$idises the metal, hich
can damage the connectors and cabling.
U!ea )$l'e!
Bemove the drain plug and drain
the filter housing. Bemove the urea
filter )% from the pump unit.
No'e: If urea solution comes into contact
ith disconnected electrical connectors,
the urea solution spreads rapidly through
the iring and o$idises the metal, hich
can damage the connectors and cabling.
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F,el 'ank
Ampty the tan" by removing the drain plug.
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0REAKS:
S,**ly Sys'e& Co&*onen's
he A$! Co&*!esso! pumps air into the air tan"s supplying the compressed air to poer the
air bra"e system and other air operated devices such as the ater tan", ire ;oss, chute loc",
tilt hopper, etc. It is lubricated by engine oil and is usually gear driven.
he A$! Co&*!esso! Go%e!no! controls hen the air compressor ill pump air into the tan"s.
hen air tan" pressure rises to the set ma$imum, or the Ncut outO level, )around 123 psi the
governor stops the compressor from pumping air. hen the tan" pressure falls to the Ncut inO
pressure )around 1'' psi, the governor allos the compressor to start pumping again.
%n A$! D!ye! helps to "eep the system free of contaminants. % filter, typically containing a
desiccant, is installed beteen the compressor and air tan" to remove moisture and oil from
the air.
A$! Tanks store compressed air. he tan"s ill hold enough air to allo the bra"es to be used
several times even if the compressor stops or"ing. he tractors supply air tan" receives air
from the compressor and delivers it to the primary and secondary air tan"s. he tan" closest to
the compressor is commonly referred to as the Net tan"O because that is here most moisture
condenses.
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D!a$n .al%es manually or automatically purge the air tan"s. Compressed air usually has some
ater and oil in it, hich tends to collect in the bottom of the tan". he ater can freeQe in cold
eather and lead to bra"e failure. Go not depend on the automatic drain valve 0 *anually drain
the air tan"s at the end of each driving day.
he A$! S,**ly Ga,6e on the dash indicates ho much pressure is in the air tan".
5ote @ ;ra"es out of adustment are the S1 violation at eigh stations and the leading cause of
bra"ing inefficiency in an air bra"e system. he manual adustment of an automatic slac"
aduster to bring a bra"e pushrod stro"e ithin legal limits is mas"ing a mechanical problem
and not fi$ing it. he manual adustment should only be used as a temporary measure to correct
the adustment in an emergency situation as it is li"ely the bra"e ill soon be bac" out of
adustment. *anual adustment of slac" adusters is dangerous because it can give the operator
a false sense of security about the effectiveness of the bra"ing system.
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A$! 0!ake Tes'
Ansuring the bra"es are in pea" operating condition is easily the single most important part of
your truc" inspection 0 Kour life and the lives of others depend on being able to stop hen you
need to. he belo guide ill help you develop a proper routine hen completing the daily
safety inspection of your mi$er truc".
T$'an A$! 0!ake Tes' P!o#ed,!es
he test must begin ith the folloing assumptionsL
M %ir tan"s ere drained during the previous post trip. Grain valves are closed.
M ire ;oss eEuipped truc"s @ heel valves closed. Beopen the heel valves upon completion of
the bra"e test to allo the system to inflateJdeflate as needed.
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A$! Co&*!esso! 0,$ld Ra'e :
M ?tart the engine and allo the air pressure to increase to 83 ?I. hen the air pressure
gauge reaches 83 ?I, adust the engine speed to 9'' B*?.
M o satisfy this chec", the air pressure must reach 1'' ?I ithin 2 minutes
A$! Leak Tes':
;efore starting this chec", the air system must be at full system pressure hich is usually
beteen 123@14' ?I. Bev the engine to 12''@14'' B*? and atch the air pressure gauge.
hen the air system is fully pressuriQed, the pressure gauge ill stop climbing and the
compressor governor ill "ic" out folloed by a N psssst” air release. Complete the folloing
stepsL
M Belease par"ing bra"e
M ?hut off engine
M Gepress the bra"e pedal as you ould in an emergency situation and hold the pedal don
for the count of one minute.
M %fter the initial drop in air pressure from depressing the bra"e pedal, the truc" must not
lose any air as detected by hearing or movement of the air pressure gauge.
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Lo A$! 5a!n$n6:
M urn the "ey to the B5 position 0 Go not start the engine
M Fan the bra"e pedal off and atch the air pressure gauge. he lo air arning light on the
dash and the buQQer must sound before the air pressure reaches !' ?I=
E&e!6en#y 0!ake Po* O,' :
urn off the "ey to stop the lo air arning buQQer
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No= o) Gea! and S$>e
GEAR DRI.E TO PARLLER SHAFT
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