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10
Chapter
I-
General Engine Repair
The
fuel pump
capacity
on
a
ll engin
es should be
1
pint
in
45
seconds or
less.
( 13)
I
NSPECT
AND
CLEAN
FUEL
PUM
P BOWL.
R
emove and
clean the fuel pump
bowl.
Install
a new
filter
on
the
223,
239,
or 256
cubic inch e
ngine.
Clean
the
filter
on
the
279 or 3
17
cubic
inch
engine.
Install
the sedime nt
bowl
and a
new
gasket.
(
14
)
CLEAN CARBURETOR
.
Clean
the
carburetor
fuel
bowl. Set the
floa
t
or
fue
l
level, and
ch
eck
the
ac-
celerator pump operation.
(IS) CLEAN
AIR CLEANER.
Clea
n
the a
ir cleaner,
oil
the
element
(dry-type),
and
insta
ll. If the air
cleaner
is
the
oil
bath-type, fill to the indicated
level
with
engine
oil of the
specified
viscosity.
(16)
TEST
ENG INE
VACUUM.
Check the engine
m
ani
fold vacuum
a
t
id le
speed.
If
t he vac
uu
m
is lower
than normal,
check for
leak-
age
at
the vacuum
lines and
intake
manifo ld. Check
the
carburetor
idle
adjustment.
If
the vacuum
is
still
below
norma
l
or
is
erratic,
it
is
an
indication
of
bad
rings,
sticky valves,
weak
valve
spring, or
leaking gaskets. If
this condition
exists, it
should be
reported to the
customer.
(
17) ADJUST
CARBURETOR
IDLE.
Connect
a
vacuum
ga
u
ge, and set
the idle
sp eed t
o
specifications
with
a tachometer
installed
o
n
t he engine. Set the idle
fuel
adjustme
nt
to the point
of
high
est a
nd steadiest
mani
fold vacuum
a
nd
/
or at
the
smoothest engine
idle.
R
eset
the
idle speed
if
required.
(
18
) CHECK
DEPOPPER
OPERATION. Check
the
operatio
n
of
the
carburetor
d ep
opper
valve
on the
256,
279, and
3
17
cubi
c
inch
engines.
(
19)
CH
ECK GOVERNOR OPERATION
-
256,
279, AND 317
CUBI
C
INCII ENGI
NES
. F
ollow
the
procedure under
"8.
i\'
l inor
Tune-Up."
(20)
ROAD TEST.
R
oad
test
the
vehicle as
a
final
check
on
the work performed.
Also, notice
the perform-
ance of
the
tran
smission,
axle,
brakes,
a
nd
any
optional
accessories.
R
ecomme
nd
a ny addit ional service
required
w hen
the vehicle is delivered to the
owner.
3. ENGINE REMOVAL AND INSTALLATION
Engin
e
removal
a
nd installation
procedures are sepa-
rated
accord
ing
to the
va rious
truck
body
sty
les.
A
separate procedure
is given for
Con
ventio na
l
a
nd
Cab
F
orward
Trucks
equipped with
F
ordomatic.
The
en gin
e
mounts
used
to
install
t
he
e
ngin
es o
n
a
work st
and are
illustrat
ed
in figs.
1,
2, a nd 3.
R.
Conventional
Truck.
T
he
en
gi ne
removal
a
nd installation
procedure
fo
r
the conventional truck
a lso applies
t
o
the
school
bu
s.
(1.)
REMOVAL.
Drain the cooling
system.
Drain
the cra nkcase.
R
e
m
ove
the hood.
R
e
m
ove the fan as-
sembly and the fan
belt.
D
isconnect
the heater hoses
at
the
engine.
R
e
move
the radiator
and
shroud
assembly.
Too· l-r5 4r~5005·D
(SPlINED
SHAFT)
Tool-T54T-COO5·E
(KEYED
SHAFT)
Fig. I-Engine Moun,-239 0,256 Cubic Inch Engine
NOTE: On
trucks
e
quipped
with an
air
cOmpre&80r
o
pen
the
air
reser voir drain
cock.
Loosen
the
fitting
at
the
reser'voir
inlet
line.
Disconnect
the
air
line
and clip at
the
front
of th
e engine,
then lay th
e line
against
th
e e
ngine
side com.partme
nt.
R
emove the air
cleaner,
the
n
tape the
carburetor air
ho
rn
closed.
D isconn
ect
the
windshie
ld wiper vacuum
hose a
t the
ma nifold.
Disconnect
the hand throttle
control, choke
cable,
accelerator
rod,
and
the
accelerator
retrac ting s
pring at
the
carburetor.
D
isconnect
the
e
n
gine
temperature se
nding unit wire,
Too,I-T52r-~)5
·
(:JD
(Splined
Shalt)
Toal-
T52T-6005 ·K1D (Keyed
Shoft
)
Fig. 2-Engine Moun' Adap'e,-223 Cubic Inch Engine
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