602
car hard to handle after a turn? If your tires show any unusual
wear patterns and/or you answered yes to any o f these ques­
tions, your car probably needs an align m en t.

Angle of
inside wheel
F igu re 19-7:
Turning
radius.

Angle of
outside wheel
F o ca l point

Checking your steering
C heck ing your steering is easy. Just stand outside your
vehicle, near the door on the driver’s side. Stick your hand
through the open window and move the steering wheel, with
your eye on the left front tire. If you can move the steering
w'heel at all before the tire starts to move, then you need to
have both your steering and alignm ent checked. There should
be no “play” in the steering wrheel before the signal is trans­
mitted to the tires.
As you drive your car, be alert to signs that it isn’t han­
dling as easily as before. If the vehicle seems to have a mind
o f its own and begins to resist you on turns (and pulling out of
turns), take a good look at your tires for signs o f wear caused
bv m isalignm ent.

603

Checking your tires for wear
You should check your tires for wear at least once a month
and before and after long trips. To determine whether you
need to (a) buy new tires, (b) have your wheels balanced, (c)
have your wheels aligned, or (d) change your driving habits,
simply read your tire treads for clues. Table 19-1 and Figure
19-8 show you what to look for.
Table 19-1

How to Read Your Treads

Clue

Culprit

Remedy

Both edges w orn

U nderinflation

Add more air, check for leaks

Center treads worn

O verinflation

Let air out to m anufacturer's

specifications

One-sided w ear

Poor alignm ent

Have wheels aligned

Treads w orn unevenly,
with bald spots, cups,

W heel im balance
and/or poor alignm ent

Have w heels balanced and
aligned

W heel im balance
or w o rn shocks

Have w heels balanced or

Edges of front tires
only worn

Taking curves too fast

Slow down I

Saw-toothed w e ar

pattern

Poor alignm ent

Have w heels aligned

or scallops
Erratically spaced
bald spots

replace shocks

( continued)

Table 19-1 (continued)
Rem edy

Clue

Culprit

W hining, thumping,
and other w e ird noises

Poor alignment, worn

Have w heels aligned or buy

tires or shocks


new tires or shocks

Poor alignment

Check w e a r on treads and act

or underinflation

accordingly

Squealing on curves


604

Figure 19-8:
W h a t the
s ig n s of
p o o r tre ad
w e a r m ean.

Severe underinflation

O verinflation

Poor alignm ent

Poor alignment

Underinflated tires wear out faster, create excessive heat,

increase fuel consumption, and make your car harder to handle.
Overinflated tires can “ blow out” more easily, wear out faster,
and make the car unstable and unsafe to handle. And a new
set o f tires on wheels that are out o f alignment can wear out
completely in as little as one day o f hard driving!
To determine w h at’s causing problems with your tires, try
the following:
♦

Look for th in gs e m b ed d ed in each tire. Do you see
nails, stones, o r’ other debris em bedded in the treads?
Remove them. But if you’re going to remove a nail, first
make sure that your spare tire is inflated and in usable
shape.
I f you hear a hissing sound when you pull a nail, push the
nail back in quickly and take the tire to be fixed. If you
aren’t sure w h eth er air is escaping, put some soapy wa­
ter on the hole and look for the bubbles made by escap­
ing air. If you’re still not sure whether the nail may have
caused a leak, check your air pressure and then check it
again the next day to see whether it’s lower (for help,
see “C heck ing your air pressure,” earlier in this chap­
ter). Tires with leaks should be patched by a professional.
I f the leak persists, get a new tire.

♦

Look at the sid ew a lls. Check for deeply scuffed or worn
areas, bulges or bubbles, small slits, or holes. Do the tires
fit evenly and snugly around the wheel rims?



605
♦

L ook at the treads. Most tires have tread-wear indica­
tors built into them (see Figure 19-9). These bars of hard
rubber are normally invisible but appear across treads
that have been worn down to Xs o f an inch of the surface
o f the tire (the legal limit in most states). If these indica­
tors appear in two or three different places, less than
120 degrees apart on the circumference o f the tire, re­
place the tire.
If your tires don’t show these indicators and you think
that they may be worn below legal tolerances, place a
Lincoln penny head-dow n in the groove between the
treads. If you can see the top of Lincoln’s head, your tire
probably needs to be replaced.

Figure 19-9:
It's tim e for
ne w tires
when
tre a d -w e a r
in dica tors
appear.

To measure tread wear more exactly, place a thin ruler
into the tread and measure the distance from the base of the
tread to the surface. It should be more than Xs inch deep.

(Note: I f your front tires are more worn than your rear ones
and show abnormal wear patterns, you probably need to have
your wheels aligned.)
♦

Pay attention to leaks. If you keep losing air in your
tires, have your local service station check them for leaks.
Sometimes an ill-fitting rim causes a leak. The garage
has a machine that can fix this problem easily.
If the garage can't find a leak, your rims fit properly, and


606
you’re still losing air, you probably have a faulty tire valve
that’s allowing air to escape. You can buy tire valves to
replace the ones on your car. Look for the number molded
into the base o f the tire valves; then buy new ones that
match it.
In the process o f replacing the valve, you will lose most of
the air from the tire, so either plan to do this job at a gas
station where you can have access to an air hose, or have a
m echanic replace the valve for you.

Words and phrase - Tit vd cum tu:
♦>

Tire size codes: cdc md ve kich cd ciia lop.

♦>


Speed ratings: toe do

•>

Tire quality grade codes: cdc md chi cap chat luqng cua
lo p
DOT identification and registration: so nhan dien va so
dang ky D O T

❖

Other sidewall information: nliUng tliong tin kliac xac
dinli tren tlianli ben cua lop.

♦> C hecking tire inflation pressure: k iem tra dp suat hai
lop.
•> A dding air to your tires: bom th em hoi
❖

Rotating your tires: xoay lop

♦> Balancing your wheels: cdn bdng cdc banli xe.
❖

A ligning your wheels: dinh thdng h a n g cdc banh xe.

♦> C hecking your steering: kiem tra do mdn lop xe
♦> C hecking your tires o f wear: con g tdc kiem tra tay lai



607

Translate the paragrap 1, 2, 3 into Vietnamese Bdi dich doan 2, 2, 3
1.

Cau true cua lop xe.
Mdi lop xe dieu co mot so thanh phan chinh (xem hinh 19-1):
♦ Mat gai la phdn cao su cua lop thudng de bi mdn vd de
bi rach nlianli. Cdc liieu hinh cua mat gai giup cho lop
khdi bi truqt tren dudng vd klioi bi dam tilling. Cdc hinh
gai nay cung la nhitng dau hieu tuyet vdi de bao cho
chung ta biet lop bi mdn. O phan chi "ltiem tra do mdn
cua lop".
♦ Mat ben cua lop la phdn lop xe ndm giiia mat gai vd
vien lop. Phdn nay duqc goi la "nhitng bi mat ndm tren
thd nil lop" duqc de cap d phdn sau cua chuong nay se
giai md tdt cd nhitng dit lieu duqc due nan tlianli lop.
♦ Vien lop la m ot vong day thep duqc dinh dang de giU
lop xe ndm tren vanli banh xe.
♦ Vo lop Id than lop ndm ben dudi mat gai vd tlianli lop.
Vd nay giup cho lop dinh duqc hinh dang khi duqc bom
cang thay vi d e cho lop bom len g io n g nliU m ot cliiec
kinh khi cdu. Vd lop duqc lam bdng nliieu vat lieu ltliac
nhau duqc g o i la cdc day bo.
♦ Cdc dai lot cung duqc lam bdng cdc sqi bo duqc cdn len
m ot ldp cao su vd ndm ben dudi mat gai vd than lop. Vd
nay giup cho lop dinh duoc hinh dang khi duqc bom cdn
thay vi de cho lop bom len g ion g nliU mot /mill khi cdu.
Lop duqc lam bdng nliieu vat lieu kliac nhau duqc goi la
cdc day bo.

Cdc dai lot cim g duqc lam bdng cdc sqi bo duqc cdn len
m ot top sao su vd ndm giita than lop

vd mat gai. Dang


608
vat lieu nay duac dung lam cdc dai vd phuong tliitc md
no boc xung quanli vien lop se xa c dinh loai lop vd gid
cd ciia no. N guyen thuy ngudi ta sii dung cotton d$ lam
cdc soi bo nhung cdc soi nay som nliUdng clio cho cdc
vat lieu tot hon nliU thep, aram id (no cilng hon thep).
Soi thuy tinh polyester, to nhdn tao vd nylon. Cdc radi­
als duoc tao dai bdng thep la danh lop pho bien

nhat

ngay nay.
♦ Van lop cd cliiec ndng d e cho khi di vdo vd ra khdi lop,
than van giQ cho khi klioi bi tlioat ra khdi lop. Moi mot
van thi ph ai cd m ot lop day d e kliong cho bui vd hoi
nUdc xam nhap vdo lo.
* Cho den tlidi gian gan day thi cdc lop duqc che tao vdi
nliieu ket cdu kliac nhau. Titng cd cdc loai lop xien cd
cdc soi bo duoc boc xun g quanli vien lop, cdc lop clieo.
Sau dd cdc loai lop nay duqc thay the bdng cdc lop cd
dai xien la no cd cdu true cu n g g io n g nhu lop xien nhung
cdc dai thi duqc lam bdng m ot

vat


lieu kliac duqc boc

xun g quanli vien lop d e g iu p cd do mdn lau hon, kho bi
dam tliung hon vd cd tinh on dinli gian hudng. Ngay nay
tdt cd cdc x e deu duqc ldp cdc lop don g tdm vd cung do
la tdt cd cdc loai xe cu n h at d eu sii dung tdt cdc loai lop
nay nen cdc loai lop xien vd cdc loai lop cd dai xien
kliong cdn duqc sii d u n g nUa.
Cdc lop d on g tdm da tro nen m ot tieu chuan do no cung
cap duqc do van chuyen tdt hon, dac biet la o tdc do cao, cdc
lop nay cd kliuynli hudng la bam xu on g m at du ong hieu qua
hon, dac biet la tai nhitng do cua; cliung cd the cung cap vdi
sd dam hoat d on g gap 2 lan so vdi cdc loai lop cd bo cheo.
Cdc lop d on g tdm cliay it tao nliiet hon boi vi no cd it ma sat
tron. (cdc loai lop xien vd cdc loai lop cd dai xien thi cd cdc
ldp boi keo ddn truyen nliieu ma sat trong vd nlueu nliiet hon


609
khi chuyen ddng). Do mdn ciia cdc lap cd thay doi tu 25000
ddm tro len phu tliuoc vdo vat lieu dai duac sd dung. Phdn
tren ciia cdc lop cd dai tliep cd the ton tai til 40000 den 100000
ddm vdi dieu liien lioat dong binli thudng.
De quyet dinli dung loai lop danh cho xe ban thi liay xem
phdn "liUdng ddn mua lop" a sau chuong nay.

2. Nhitng bi mat tren thanh ben cua lop, ditctc
bQC l o !


Co nliieu ngudi sdn sang bo ra them sd tien de mua cdc
lop duqc danli ten tlianli cdc cliU cai Ion mau trdng tren
thanli lop nhu macho Wildcats hay Tough Guys nhung ban cd
biet rdng sU phong pliu ciia thdng tin viet bdng nhitng chit cai
nlio nliat mau den tren tlianli lop thi cd the cd gid tri hon
nliieu ve mat lau ddi ltliong vd thdng tin nay duqc viet tu do
neu ban biet cacli giai md no. Cho du ban ltliong phai la mot
ngi/di td md vdi dit lieu a cdc phdn sau day cung cd the giup
ban khi mua vd bao duong cdc lop.

Cac md ve kich cd cua lop.
Vi du day la thdng tin ve mdt md lop m etric P thudng gap
dd la P205 /75R-14:
♦ P la loai xe (trong trudng liqp nay la lianh liliach. Cdc
md liliac bao gom L T dung cho xe tai nhe vd T dd la
dung tain thoi hoac lop dit pliong)
♦ 205 la chieu rong cua mat cdt lop duqc do ngang qua
mat ga tit tlianli ben nay qua thdng ben kia tinh bdng
m l.(trong trudng liqp nay do rong cua lop la 205)
♦ 75 la ty le canh ben thay sd seri lop - dd la ty le eliieu
cao tlianli ben cua lop so vdi chieu rong (eliieu cao cua
thanh ben lop bdng 75% so vdi clueu rong cua no). Cdc
lop cd cdc sd s e n thap (nho hon 70) thi duqc xem la cdc
lop cd mat hinh thap vd cd tlianli ben ngan.


610
♦ R la loai lop. (R d on g tdm, B la co dai ch eo, D lop bo
cheo hoac lop bo xien va E la hinh elip. T rong trudng
hop nay thi lop nay g o i la lop don g tarn)

♦ D uong kinh ciia banli x e duqc do bdng don vi inches,
(trong trudng liqp nay dudng kinh la 14 inches)

Toe do
D oi khi co m ot cliU cai p h u xuat hien giQa m at cdt vd loi
lop chdng lian nliu P 2 0 5 / 75SR 14 chQ cai phu S chi mite toe
do the liien tdc do an todn toi da cua lop. MQc tdc do ltliong
ndi len duqc dieu gi ve liet cdu do van chuyen do mdn ciia lop
nhitng no do ltlia ndng cua lop chiu duqc cdc m uc nluet do cao
do toe do cao tao ra. Dudi day la m ot bdng liet ke cdc cliQ cai
chi mQe toe do cd y ngliia la g i:
♦ F = 50 mph
♦ G = 56 mph
♦ J = 62 mph
♦ K = 68 mph
♦ L = 75 mph
♦ M = 81 mph
♦ N = 87 mph
♦ P = 93 mph
♦ Q = 100 mph
♦ R = 106 mph
♦ S = 112 mph
♦ T = 118 mph
♦ U = 124 mph
♦ H = 130 mph
♦ V = 149 mph


611
♦ Z = 149+ mph

Ban cung co the tim mile toe do duqc liet ke cung voi cdc
chi so ve tai trong cua lop chdng han nhu 97H. Trong trUbng
hop nay 97 la chi so ve ty trong, H la chi mile toe do.
Neu xe cua ban nguyen thuy duqc ldp cdc loai lop chi toe
do thi ban phai nen thay cdc loai lop nay bdng cdc loai lop chi
mite toe do.

Cdc md chi cap chat litcfng cua lop
Hay tim cdc cap lop nay tren thanh bi cua lop hoac tren
thanh ben ciia lop hoac tren cdc nhdn ddn vdo mat gai lop.
dudi day la y ngliia cua chung:
♦

Do mon ciia lop: phu tliuoc vdo tinli trang kiem tra lty
ludng. T rong tliUc te thi m ot loai lop duqc danh gid
bdng chi so 200 thi no se co do mdn mat gai gap hai lan
so vdi loai lop duqc danli gid chi so 100 - neu tdt cd cdc
yeu to ga y mdn kliac deu nliu nhau.

♦ Sm'c k eo: dd la cap AA, A, B, hoac C no the liien ltlia
nang cua lop dilng tren dudng nliUa Udt lioac tren cdc
via lie beton g ditdi cdc dieu liien kiem soat (AA la cong
suat cd the la tot nliat) cdc cap nay chi pliu tliuoc dieu
liien thdng d phia trildc chit liliong pliu tliuoc vdo doan
cua hay doan quay dau. M ot loai lop cd cap C la no da
dat duqc tieu cliuan kiem tra cua chinh pliu trong khi
cdc loai lop B, A, vd AA (theo trinh tu giam ddn) thi no
vilqt qua tieu cliuan

cua cliinli pliu.


♦ N h iet d o: Cap A, B, vd C nay la no the hien cliiu nhiet
vd klia nang tai nhiet neu lop cd dung do can vd khong
qua tai. Cap C dap itng cdc tieu cliuan toi tliieu ciia Hoa
Ky trong khi cdc cap B vd A thi no vUqt qua tieu cliuan
ciia Chinh Phu.


612

So nhan dien vd so ddng ky DOT
So nhan dien D O T xac dinh tren thanh ben cdc cliitc ndng
nhu la m ot so ddng ky cho lop trong trudng hap cd yeu cdu
tlidc mdc. Sd nay cho ban biet noi vd thai gian sdn xuat cua
lop. Hau liet cdc di2 lieu viet bdng md thi klion g cd j nghla
quan tron g Idm. NliUng neu ban to md tlii vi du sau day se chi
cho ban b iet nliieu chit cai vd chi? so kliac nhau cua mot mau
md DOT, D O T W O K A A B C 262, cd nghla la:
♦ D O T cd nglila la lop nay dat duac lioac vi/qt qua tieu
cliuan an todn cua cuc van tai Hoa Ky
♦ W O la nha m ay sdn xuat ra lop. Bdi vi cdc lop duqc sdn
xuat d cdc nha m ay kliac nhau nen ban liliong cdn biet
tdt cd cdc bien doi cua md nay. N eu ban quan tdm muon
b iet cdc noi sdn xuat ra cdc lop tlii liay lioi ngudi ban
hang.
♦ K A la chi cho biet kich cd lop. T rong trudng hop nay
kich cd lop la P194 / 75R14. Bdi vi kich cd lop cung duqc
xac dinh tren tlianli ben cua lop nen ban ltliong cdn biet
tdt cd cdc bien doi cua md nay.
♦ A B C la no ch i cho biet nhdn liieu vd tinh cliat cua lop

thay vi giai md cdc chit nay thi ban cd th e doc trong so
hudng ddn m o td lop d e biet chi tiet.
♦ 2 6 2 la no chi tlidi gian sdn xuat lop (tron g trudng hop
nay sd 262 cd nghla la lop duqc sdn xuat trong tuan thii
2 6 cua ndm 1982 that la trang nlia ph ai lilion g?)
D e biet them nhieu chi tiet trong viec mua lop thi hay xem
"liUdng ddn mua lop d sau chuong nay"

phan

Nhting thdng tin khde xde dinh tren thanh
ben cua^lop.
H ay ltiem tra cdc tlianli ben ciia lop d e b iet duqc cdc dit
lieu an todn sau d r y :


613

♦

Tai trong toi da: Trong litqng cua lop la bao nhieu thi
co the la an toan thudng la bieu luen bdng kg hoac bdng
pounds

♦ A p suat toi da: la dp suat khi toi da de co the gilt an
todn cho lop thitdng duqc the hien bdng pounds/ inches
Ban cd the tim thay cdc cacli liitang ddn ve kiem tra cdc
dp suat lop, cach doc tren mat gai de tim dau moi vd cdc cong
viec kliac md ban co the tliitc hien tren lop a phdn sau ciia
cliUong nay goi la cliam soc lop.


3. HiXdng ddn mua lop
Dudi day la m ot so lop md ban cdn phai danh gid:

♦ Cdc
tren
ddu
(bim
hoat

loai lop chay of tdt cd cdc mua la tieu chucin
liau liet cdc xe hai. Mite toe (xem mite toe do a phdn
cua chuong nay) thudng la S lioac T. neu "M+S"
vd tuyet) duqc in d tlianli ben cua lop thi lop se
dong tot trong tinh trang tliai tiet kliong cdn phai

sit dung cdc loai lop dung de chay trong tlidi tiet cd
tuyet.
♦ Cdc lop xe du lich thtfctng thi ddc hon

so vdi cdc lop

xe chay trong tdt cd cdc mua vd cluing cd ddc tien hay
kliong phu tliuoc vdo titng sdn pham. Cdc loai lop nay
thudng cd mite toe do la S lioac T

♦ Cdc mu'c co hieu suat duqc thiet ke danli cho cdc ngudi
lai xe bac. Cdc lop nay phuc vu tot han cho hoat dong
thdng vd chay den nhitng doan cua nlutng thudng cd do
on hon vd mdn nlianli han. Cluing thudng duqc dinh tdc

do Id H vd cd mat hinh rong thap hon.
♦ Cdc ld p co hieu suat sieu cao vd cd cd cdc mat tich
citc vd mat tieu citc vdi mot mite do Ion hon: cdc lop nay


614
cliay nlianli han, lioat don g thdng a dieu kien tot hon a
nhitng dieu liien dm Udt vd liho rao nhung chau it tliodi
mdi han vd cliay tot han. Cdc lop nay cd be mdt rong
hon vd thudng cd mite toe do la V hoa c Z.

♦ Cdc lop xe tai n h e: cho cdc xe tai nlie, cdc loai xe cao
cap. Cdc lop nay cd nliieu dang ltliac nhau duqc tliiet he
lioat d on g a nhitng dieu hien binh thudng cliay tren dudng
vd ngoai dudng lioac pliuc vu cho cd hai. Cdc mat gai
day han p h u c vu chay a dia liinli ngoai dudng luu thdng
no se cung cap m ot site heo manli han tren cdc be mQt
ltliong lat dudng. Cdc lop xe tai n h e cu n g dd giam ve site
d id binli thudng d id nang lioac chd sieu ndng.
♦ C d c lop x e ch ay tren tu yet co th e la tot han so vdi cdc
lop xe chay a tdt cd cdc m ua d u n g d e cliay a tren cdc
vung niii ncri cd tuyet rai nliieu nliUng chu ng rat on vd
liliong hoat d on g tot tren cdc dudng luu thdng hoi ham.
Do vay chi sit du ng cdc loai lop nay klii cdn thiet.
♦ Cdc loai lop xep cd the duqc cliay md kliong cdn pliai co
bdt ky m ot dp suat khi ndo ben tron g lop. Cdc loai xe sit
d u n g lop xep thi ltliong cdn pliai cd kich x e hay lop dit
p lion g (neu ban sd du ng m ot loai x e ddi 1997 hay loai xe
mdi hon C hevrolet C orvette hay m ot loai xe mdi cd trang
bi m ot loai tUang tu nliU vay thi chdc lidn ban cd loai lop

ddng tdm dac b iet nay). Cdc tlianli ben cua lop thi no co
cdc nu t k et liqp dac b iet d e lam ch o lop klioi bi xep
xu on g khi lop mdt dp suat khi. Ban cd th e lai xe vdi mot
sd lop x ep vdi tdc do len den 50m /gid hoac 50 dam
hoac cao hon md liliong lie liU liong lop.
Cliay lop xep d cdc mite tdc do cao a tron g m ot tlidi gian
ddi thi cd the bi. h on g lop do vay cdc nlia sdn xuat xe hen
cd ldp m ot

lie thdng canh bao vi du x e C orvette thi cd


615
cdc bo cdm bien dp suat lop a moi banh xe do vay tai xe
co the duqc bao lueu khi mot hay nlueu lop bi xep lioan
todn. Do ngudi tai xe kliong the cdm nhan duqc bdt ky
mot sU cdm nlian ndo khi lop bi xep nen den bao hieu se
phat sang tren bdng dieu ltliien bao liieu cho ngudi tai
xe biet gidi lian toe do dieu ltliien cua tai xe vd klioang
cacli de tranli gay liong them cho lop hay banli xe.
TrUdc khi quyet dinli ve mot loai lop dac biet thi ban liay
nliin ky thoi quen lai xe cua minh:

Ban co kho dieu khien banh xe hay k h o n g ? N eu ban
cd khuynh hudng dot cliay cao su khi den nhitng doan cua khi
kliai lianli vd khi dilng thi ban pliai biet la cao su dd xuat
pliat tit ddu. Mot cap lop re tien cd the bi mdn rat nlianli, ban
cd the mua mot loai lop cd cliat luqng tot nliat trong klia ndng
co the.
Ban co lai nhanh va lai nhieu tren ditdng cao toe

hay khong ? Mot cliiec cd be mat cling hon thi se lau mdn hon
vdi cdc dieu liien nay.
Ban cd chay xe nhieu tren mat diidng co dd go ghe,
cd chd nhieu tai tron g hoac de xe diidi trdi ndng trong
mot khoang thdi gian ddi hay k h o n g ? Ban se cdn cd nliUng
cliiec lop cd cliat luqng cao hon cd do ben hon de trdi qua
nhitng tliacli tliitc nay.
Thdi tiet nhu' the ndo d khu vitc ciia ban? N gay nay,
cdc loai xe ddn dong bdng cdc banh xe trudc vdi cdc loai lop
chay trong tdt cd cdc mua duqc xUong sdn suat vdi cong nghe
cao vi no cd site keo manli hon so vdi tdt cd cdc loai lop cu
chay d nhitng vung cd tuyet md da phai thay the khi mua he
dd den. Tuy nliien neu ban cliay xe dudi nhitng dieu kien citc
ky kliac ngliiet cdn phai kiem tra cdc loai lop thiet he cho cdc
dieu kien thoi tiet nay: neu tro mita nhieu thi ban hay tim
nhitng cliiec lot phuc vu cho trdi mita cd cdc ranli gai sieu
rong. Cdn d nhitng noi cd nliieu tuyet hay d cdc doi cd da thi
tim nhitng noi cd clul M +S (bun vd tuyet) glu tren thanh ben


616
cua lop.
Co ph a i ch ay xc hau hct tron g thanh p h o ncfi phai
d d n g nhieu vd qu ay ddu n h ieu hay k h o n g ' Thi co cdc
loai lop m em hon co cdc mat gai ron g hon la phu hop nhat.
N h u vay neu ban co y dinh g id x e lai trong vong mot vdi
ndm thi ve mat lau ddi ban co th e tiet kiem tien bdng cach la
chap nhan nlidng cliiec lop ddc tien hon, ben hon so vdi nlidng
cliiec lop re tien hon hay nlidng cliiec lop duqc danli gid sii
du ng it hon 40000 dam. NliUng cliiec lop re tien se mdn nlianli

hon vd ve m at lau dai thi se ddc hon neu ban di/a ra mot tinh
todn ve gia mua, gid lap rap, gia cdn chinh d bo lop lie tiep.
Con m ot dieu niia la neu ban bi x ep lop lioac lop xe liliong
bam tren mat dudng thi pliai chiu m ot th iet hai Ion hon nhieu
neu xe liU liong.
* Ban co the tim cdc d d lieu xac dinh dung liicli cd lop cho
xe cua ban tron g tai lieu liUdng d en cua nha sdn xuat
hay tren nhdn ddng vdo xe. N eu liliong co hai dd lieu
nay thi hay hoi ngudi ban hang.
* Cho du la ban kliong lie m ua cdc loai lop nlio hon cdc
loai lop danli x e ban nliUng ban cung cd the mua cdc
loai Ion hon cd hay 2 cd (neu do h o ciia banh xe cho
pliep) de di chuyen tot hon vd cd ltlid ndng chuyen chd
tai trong nliieu hon. T uy nliien ban nen mua cdc loai lop
Ion nay thanh cap vd ldp len co t true. H ay hoi tliq may
hay ngUoi ban h a n g lop xe hoac phu tung xe noi tieng de
biet dung p h a m vi kich cd lop danh cho xe ban. De biet
them chi tiet tlii liay xem phdn sau cua chuong nay duqc
goi la hudng ddn mua lop.
* Cdm sd du ng hai lop tren cu n g true xe cd kich cd liliac
nhau.
* N eu ban chi thay m ot hodc 2 lop thi hay thay cdc lop
trudc de dieu kliien vd thdng 6 nlidng doan cua tdt hon (bdi


617
vi trong luqng trubn den phia trudc khi ban thdng xe).

♦ Neu ban vdn dung nhUng loai lop cd bo xien hoac


cd

dai xien tren xe bdt budc ban pliai thay tdt cd cdc ldp
nay trong cung m ot thdi diem bang cac loai lop ddng
tdm khi cluing bi mdn. Ban kliong the thay nlueu loai
lop ltliac nhau tren cung xe; md ban phai thay cung loai
lop tren tdt cd bon bank. Mi(c do cliay xc rat Ithac nhau
den mile cdc lop ddng tdm no se bi lech liang neu ban
thd ldp tdt cd cdc lop bdng cdc lop ddi cu.
♦ Phai nlid la ban phai til tao do ldp cua cdc lop mdi, do
vay ban ltliong nen lai xe nlianli hon 60 dam /gid trong
vong 50 dam ddu tien tren cdc lop mdi hay lop dit phong.
♦ Hay cdt gift cdc lop mdi md ban ltliong sit dung trong
chd toi de xa chd nguon nliiet manli vd cdc md to dien vi
no se tao ra cdc ozon.

Notes of figure - Chu thich hinh
1

Hinh 19-1: H ieu m ot cliiec lop qua liinli ve

2

Hinh 19-2: D ung m ot dp lte do lop de Idem tra xe xem lop
cd dung do cdn hay ltliong.

3

Hinh 19-3: cach de thay ddi lop


4

Hinh 19-4: Goc nghien g tdi cua true banh xe

5

Hinh 19-5: do nghieng cua cdc banli xe so vdi mat plidng
dilng.

6

Hinh 19-6: Do clium ciia cdc banli xe.

7

Hinh 1-9-7: Ban kinh quay

8

Hinh 19-8: Ddu hieu mdn mat gai lop cd y nghla gi

9

Hinh 19-9: Den luc ban phai cdn nen thay lop mdi khi
xuat hien cdc ddu hieu chi do mdn mat gai tren lop.


618

Troubleshooting Leaks,
Squeaks, Smells, and
Strange Sensations
Purpose and layout - Muc dich vd bo cuc:
□

R ecognizing the sounds o f trouble: nhan biet nliQng tieng
on cua su co.

□

G ettin g rid o f squeaks, rattles, and vibrations: xti ly
nhitng tien g keu Idc cdc lach each vd nhUng dao dong.

□

Sniffing out unusual smells: p h a t hien ra cdc mui la

□

D eciphering smoke signals: xa c dinli nhitng tin hieu tao
klioi

□

Locating and dealing with leaks: dinli vi vd xii ly nhitng
cho bi. rd ri.

□

Getting to the bottom o f strange sensations: kiem tra vd
giai thich nhitng cdm g ia c la.

□

T rou b le sh o otin g with directional signals: xii ly sit cd
cdc tin h ieu chuyen liUdng.

As you w ork on your vehicle, you’ll get to know it better.
Before long, you’ll becom e m ore sensitive to its signals. If
som ething sounds funny or smells funny or just doesn’t feel
right, you’ll soon sense it. This can help you forestall expen­
sive repairs, because you’ll be able to prevent trouble or catch
it before it becom es a major problem. This chapter shows you
how to use your eyes, ears, and nose to sense automotive


619
symptoms, and how to deal with those symptoms.
The words in special type are defined in the Practical
Glossary o f Automotive Terms at the end of this book.

1.Sounds
You probably know how your vehicle sounds when it’s run­
ning properly, and your ears can alert you to anything that
sounds strange. Well, listen to your ears! If you hear a strange
or different sound, pay attention to it and react accordingly.
♦

If a fan belt or accessory belt “sings” (m akes a con ­
tinuous, h igh pitch ed sound), readjust or replace it.
These belts should have at least half an inch of play and
shouldn’t be frayed, cracked, or glazed on the underside.
Some belts tend to sing more than others. Rubbing a bit
of petroleum jelly on the undersides o f these belts usu­
ally quiets them down. You can find instructions for ad­
justing and replacing belts in Chapter 14.
D on’t drive with a broken fan belt. If you carry a spare
belt or an old belt in the trunk, you may be able to save
yourself towing charges.

♦

If your radiator “sin gs” (sim ilar sound, d ifferen t
tune), check the radiator pressure cap. The rubber gas­
ket may be worn, and steam from the hot engine may be
escaping past it. Chapter 14 tells you how to remove a
radiator cap safely

♦

If your tires squeal on curves - and you aren’t sp e ed ­
ing - check their inflation pressure, treads, and align ­
ment by using the instructions in Chapter 19.

♦

If you hear a w hining or hum m ing sounds on curves,
your w heel bearings may be wearing. Chapter 18 turns

you on to the sensual thrill of repacking them with your
bare hands.

♦

If your tires “tram p” (make a w eird, rhythm ic sound


620
as you d r iv e ), check inflation, tire w ear, and wheel
b alan cin g (see Chapter 18).
♦

If you h ea r sq u e a lin g w hen you step on the brake,
you’ve probably worn the brake pads down too far. Get
them replaced immediately. Some disc brakes are natu­
rally noisy, but if the sound gets louder, take heed.

♦

If som eth in g ticks rh ythm ically w hile your engine
idles, shut o ff the engine, wait ten minutes, and then
check the oil level. The hydraulic lifters that operate the
valves in your engine can make these noises if you’re
down as little as a quart o f oil. If the level is low, add oil
up to the “ Full” line on the dipstick and check again in a
couple o f days. I f you have enough oil, have a mechanic
check the valve adjustm ent if your car has adjustable
valves (some d on ’t). Faulty valves can seriously affect your
car’s perform ance and fuel consumption.

♦

If you h ear a loud kn ock in g sound in your engine,
pull to the side o f the road im m ediately and call for road
service. It may be just a loose rocker arm or carbon buildup
inside the engine, but if it’s a loose b e a rin g or a faulty
piston, letting it go unheeded can destroy the whole en­
gine.
Mild knocking or “ pinging” may be the result of using
fuel with the w rong octane rating. C heck your owner’s
manual to see w hether your vehicle needs low-octane or
premium gas.

♦

If you hoar the en g in e running after y o u ’ve turned
o ff the ign ition , your engine is dieseling. This condition
is often flue to using fuel with too high an octane rating,
but a tank o f inferior gas or an idle speed that's set to
high may also be the culprit.

♦

If you h ear ru m b lin g noises com in g from under or
tow ard the re a r of the veh icle, the trouble could be a
defective exhaust pipe muffler, or catalytic converter; or


621

it could be coming from a worn universal joint or some
other part of the drive train. Have a service facility put
the car up on a hoist and find the problem.
♦

If you hear clunking under your vehicle, especially
when you go over a bump, check the shock absorbers
and suspension system. If it’s toward the rear, your tailpipe
or muffler may be loose.

♦

If you hear a w histling noise com ing from under
the hood, check the hoses for vacuum leaks. If the whis­
tling comes from inside the vehicle, there’s probably a
leak in the weather-stripping. Patch the weatherstripping
according to the directions in Chapter 24.

♦

If you hear an unlocatable sound, get an old stetho­
scope from a medical supply house or ask your family
doctor. As shown in Figure 20-1, take off the rubber disc
and insert a piece of tubing in its place (about 134 inches
will do). Then put the plugs in your ears, run the engine,
and move the tube end o f the stethoscope around the
hood area. The stethoscope amplifies the sound as you
near the part that’s causing it.

Figure 20-1:

A piece of
tubing and
an old
stethoscope
make an
efficie n t
tro u b le ­
shooting
device.


622
A metal combination wrench w orks the same way. Place
one end o f the wrench on the bone behind your ear and,
leaning over, place the other end o f the wrench on the
parts that seem to be the source o f the noise. Be careful
not to get a shock or get your hair tangled in the fan.
♦

I f you r b ra k es squeal, the brak e lin in gs may be glazed
or worn. Som e disc brake pads have built-in wear sen­
sors that squeal when it’s time to replace them. Even
though som e disc brakes tend to squeal under normal
circumstances, it’s safer to have the brakes checked, or
follow the instructions in C hapter 18 and check them
yourself.

♦

I f the car id les with an offb ea t rh yth m , it isn’t be­

com ing creative; it’s probably m isfirin g - one of the spark
plu gs or the wires that connect them to the distributor
cap may be at fault. Try the following:
• With the engine off, check the spark plug cables for
breaks or shorts in the wiring.
• W ith the en gin e off, rem ove the spark plugs one at a
tim e and c h e c k w h e th e r t h e y ’ re c le a n and properly
gapp ed . Replace any that are fouled or burned.
I f that doesn’t help, have a technician check the igni­
tion system with an electronic engine analyzer. People
used to check spark plugs by holding the end o f the spark
plug cable close to a metal surface to see whether a spark
ju m p ed across when the en g in e w a s cranked, but the
high voltage in most ignition system s now makes that
procedure extrem ely dangerous.

♦

If the id lin g is rough but e v en and you r vehicle has
a c a rb u re to r, the carburetor settings may need to be
adjusted. Chapter 13 shows you how to do this yourself.
I f that doesn’t work, you may need to replace the car­
buretor. Fuel-injected vehicles d on ’t have carburetors, and
a technician must check and adjust these complex elec­


623

tronic systems. Try checking the compression in each
cylinder, following the instructions in the section o f Chap­

ter 13 called “Checking the Compression in Your Cylin­
ders.” If the engine needs to be rebuilt, you may prefer to
get another engine -or another vehicle.
An easy way to see whether your car is idling evenly is
to place a stiff piece o f paper against the end o f the
tailpipe while the car is idling (with the em ergen cy
brake on, please). Doing so amplifies the sound and en­
ables you to hear the rhythm. A misfiring cylinder comes
through as a pumping or puffing sound. An even but rough
idle is a clue that it’s time to retune your carburetorespecially the idle m ixture and idle speed screw s.
Chapter 13 has instructions for doing this job.
♦

If your car sounds like a je t plane or m akes some
other loud, abnorm al sound, a hole in the m uffler is
probably the cause. Replace it immediately: Traffic cops
hate noisy mufflers, and carbon monoxide hates people!

♦

If the horn is stuck, your vehicle is producing what
may be the worst noise it can make. Before this happens,
have someone honk your horn until you can locate it un­
der your hood. There are usually two horns. Each has a
wire leading to it. I f your horn gets stuck, pull these
wires to stop the noise (see Figure 20-2) - sometimes you
have to pull only one. When you have the horn fixed, tell
the mechanic that you pulled the wires and find out why
the horn got stuck. (If you can’t get at the horn wires,
disconnect one battery terminal or pull the fuse that goes

624

Figure 20-2:
If your horn
gets stuck,
pull a w ire
to silence it.

to the horn to stop the noise.)
♦

If your car sou n ds like an old taxi, especially when
you drive it on a b u m p y roa d , it may just need lubri­
cation (see Chapter 16). H ow ever, the problem might be
worn shock absorbers or struts, suspension ball joints, or
broken stabilizer links (see Chapter 11).
You may get used to the squeaks and groans, but they
also indicate wear, because th ey ’re caused by parts rub­
bing together or m oving without the proper lubrication.
Obviously, action is called for. The following section may
be o f help.

2. Squeaks, Rattles, and Vibrations
If you hear suspicious rattles, squeaks, or vibrations, you
may be able to save you rself som e m oney by checking and
tightening the follow ing items before seeking professional help:
♦

Loose screw s and bolts (C heck both inside the vehicle
and under the hood.)

♦

R earview and side m irrors

♦

D ash b oard k n obs and trim

♦

S ou n d -system sp e a k e r grills

♦

W in dow and door cran ks and locks


625
♦

A shtray (Is it empty? Does it fit .snugly?)

♦

Glove box (Is the door shut tight? Is anything in the
glove box rattling around?)

♦

Hubcaps (If your vehicle has them, remove them and
check inside for pebbles.)

♦

Outside trim

♦

Trunk (Is som ething you’ve stashed in there moving
around?)

If none o f these is the culprit, or if the noise persists, have
a repair facility find the cause. Often, something inside the
vehicle vibrates sympathetically because another part of the
vehicle is running roughly.
Many squeaks respond well to a lube job (see Chapter 16
for details on doing one yourself). If there is a persistent
squeak under the vehicle, your mechanic may be able to in­
stall an additional grease fitting in the squeaky area at a low
cost. Tweety Bird and other old Mustangs o f her vintage were
prone to squeaks in the A -frame under the front bumper. A
grease fitting on each side o f the upper control arm cured the
sound effects quickly and cheaply.

3. Smells
Ideally, other than that new-ca” smell, the only odors you
should smell inside your vehicle should come from smelly things

that you’ve put in it: the takeout lunch that you bought at a
drive-through, the perfume that your 6-year-old squirted all
over herself, your not-so-freshly groomed dog who’s pressing
his nose against your recently washed windows. You can get
rid of persistent odors easily by using Febreze, a spray that
eliminates odors rather than masking them. But if you smell
any of the items in the following list, take immediate action
to correct it:
♦

Do you sm ell rubber burning under the hood? One


626
o f your hoses may have come loose and landed on a hot
part o f the engine. Rescue it before it melts through.
♦

Do you sm ell bu rn ed ru b b er with the hood closed?
Feel your w heels. I f one is hot, a brake shoe may be
dragging, or you may have left the parking brake on. If
neither o f these checks out, an overheated clutch may be
the cause.

♦

Do you sm ell oil b u rn in g? (It has a thick, acrid odor.)
First check the oil dipstick by following the directions in
C hapter 3. Your oil pressure gauge may be lying, and you
may be out o f oil. Or your engine may be overheating,

and your temperature gauge may be broken. If neither is
the case, look a r o jn d the engine for an oil leak that may
be frying in the heat o f the running engine. If the oil
situation seem s to be okay, check the transmission fluid
dipstick. Som etim es a faulty vacuum modulator can si­
phon the fluid out o f the transmission and feed it to the
engine, w here it’s burned. Also, if the transmission fluid
is very low, it can be burned in the transmission because
the gears aren’t lubricated enough and are getting very
hot.

♦

Do you sm ell oil or e x h a u st fum es in the passenger
co m p a rtm e n t? The cause could be burned oil from the
engine area - but it could also be a faulty exhaust pipe
under the car that lets exhaust gases get into the vehicle
through the floorboards.
Exhaust fumes are full o f carbon monoxide, so if you smell
oil or exhaust in the car, be sure to keep your windows
open at all tim es and have the problem checked out as
quickly as you can. W e ’ve all heard stories about people
who have died on the highw ay from carbon monoxide or
from passing out at the wheel because o f it. Such stories
are true.

♦

Do you sm ell so m e th in g sw eet and ste a m y ? Take