1953 JEEP DJ gas tank size

'Jeep'
UNIVERSAL
SERIES
SERVICE
MANUAL

C

FIG.
C-22—-CHECKING
FUEL
PUMP
PRESSURE
—
DAUNTLESS
V-6
ENGINE a
couple of strokes to be sure the pump is primed.

Using
a half-pint
bottle
or similar measure, pump
Vi
pint [0,24 It] of fuel by cranking the
engine

with
the starter motor. Count the strokes neces­
sary
to
fill
the measure. If more than 20 strokes

are
required, the fuel pump is inefficient, the tank
line is leaking air, or the fuel supply is restricted.

Check
fuel filter in the fuel tank if line is restricted.

C-24.
Check Manifold Vacuum

To
check the intake manifold vacuum on the
Hurri­

cane F4 engine, remove the ventilation valve and

L
fitting from the manifold and install special adapter. On the Dauntless V-6
engine
remove the
pipe plug located in the right
rear
of the intake
FIG.
C-23—CHECKING MANIFOLD VACUUM
—

HURRICANE
F4
ENGINE
manifold and install special adapter. Connect the

vacuum
gauge
tube to the special adapter as shown

in
Fig. C-23 for the
Hurricane
F4 engine.

Start
the engine. Connect a Tachometer
Tool,

C-3896,
from the distributor
primary
terminal to ground and set the
engine
speed at the specified

rpm.
given in Par. C-30. Observe the vacuum
read­

ing and interpret as follows:

a.
A steady reading from 18" to 20" [457 a 508
mm.] of mercury is a normal reading, indicating
that valve and
spark
timing, valve seating, and
piston ring sealing are all satisfactory.
b. A steady but below normal reading indicates

a
condition common to all cylinders such as a

leak
at the carburetor gasket, late ignition or valve
timing, or uniform piston ring and bore wear.

c.
A slowly fluctuating or drifting reading in­ dicates that the carburetor idle mixture is incorrect

Look
for the cause in the fuel system.

d.
A rhythmic pulsating reading is caused by a
condition affecting one or more cylinders, but not

all,
and indicates leaky valve, gasket blowby, re­
stricted intake port, or an electrical miss.
e. An intermittent pulsating reading is caused by

an
occasional malfunction, such as a sticking valve
(all
valves may be
erratic
in operation if the valve
springs are weak), electrical miss caused by insuffi­
cient distributor point tension or low coil
voltage

coupled with inconsistent
spark
plug
gaps
or fouled
plugs, or
dirt
in the fuel system finding its way into
passages of
critical
size or valve
seats
in the
car­

buretor.

f.
A normal reading that quickly falls off (with

engine
running at
2000
rpm.) indicates exhaust
back
pressure caused by a restriction in the exhaust
system.

g.
Make indicated corrections to bring vacuum to 18" to 20" [457 a 508 mm.] of mercury normal

reading.

C-25.
Carburetor Adjustments

•
Refer to Fig. C-24, C-25 and C-26.

Carburetor
adjustments should not be attempted

until
it is known that
engine
ignition and com­
pression are in
good
order. Any attempt to adjust

or
alter the carburetor to compensate for faulty conditions elsewhere
will
result in reduced econ­
omy and overall performance.

Caution:
If an
engine
is idling too slow or rough,
this may be caused by a
clogged
ventilator valve

or
hose;
therefore, never adjust the carburetor idle
without first checking the crankcase ventilator
check valve and
hose.

The
air cleaner must be left in place while making
idle speed and mixture adjustments. All lights and accessories, must be turned off. The positive
crank­

case ventilator system should also be in
good
oper­
ating condition when making carburetor adjust­ ments.
Either
of
these
items noticeably affects the

air
fuel ratio at idle.

•
Hurricane
F4 Engine.
Note:
The idle mixture adjustment procedure for
the late model
YF-4941S
and
YF-6115S
Carter

31

p

BRAKES
be either a defective master cylinder or the use of
low grade brake fluid which has expanded because
of heat. Use standard duty brake fluid conforming to
SAE-J1703
specification.

P-7.
Bleeding
Brakes

The
hydraulic
brake system must be bled whenever

a
fluid line has been disconnected or air
gets
into the system. A leak in the system may sometimes
be indicated by the presence of a spongy brake
pedal.
Air trapped in the system is compressible

and
does
not permit the pressure, applied to the
brake
pedal, to be transmitted solidly through to
the brakes. The system must be absolutely free
from
air at all times. When bleeding brakes, bleed
at that wheel with the
longest
line from the master
FIG.
P-5—BLEEDING
BRAKES

1—Bleeder
Screw
cylinder
first, the next
longest
second, etc. During
the bleeding operation the master cylinder must
be kept at least %
full
of hydraulic brake fluid.

To
bleed the brakes, first carefully clean all
dirt

from
around the master cylinder filler plug. If
bleeder tank is used follow the manufacturers in­
structions.
Remove the filler plug and
fill
the master
cylinder
to the lower
edge
of filler neck.
Clean
off

all
bleeder connections at all four wheel cylinders.

Attach
bleeder
hose
and fixture to right
rear
wheel

cylinder
bleeder screw and place end of tube in a
glass jar, and submerged in brake fluid. Open the bleeder valve one-half to three-quarters of a
turn.

See
Fig.
P-5.
Depress the
foot
pedal, allowing it to return very
slowly. Continue this pumping action to force the
fluid
through the line and out of the bleeder
hose
which
carries with it any air in the system. When bubbles cease to appear at the end of the bleeder
hose, close the bleeder valve and remove the hose.
After
the bleeding operation at each wheel cylinder
has been completed,
fill
the master cylinder reser­
voir
and replace the filler plug.
Do not re-use the liquid which has been removed

from
the lines through the bleeding process because
of air bubbles and
dirt.

P-8.
Brake Hoses

a.
Hydraulic
lines (tubing and hose) are the means
of transmitting fluid under pressure between the master cylinder and the wheel cylinders.

Note:
On
some
vehicles a proportioning valve is
located in the
rear
brake line along the inside left
frame
side
rail.
The valve is not serviceable and
must be replaced as an assembly.

Should
replacement be necessary make certain the valve is properly positioned with the centerline of
the hex plug (in the bottom of the valve) in the
vertical
position. Refer to Fig. P-l.

The
hoses
are the flexible links between the wheels

or
axles and the frame or body. The
hoses
must

withstand
the fluid pressures without expansion
and
must be free to flex during spring deflection
and
wheel turns without causing damage to the
hose.

b.
Hydraulic
lines are subject to damage and
deterioration. Hoses should be inspected for cuts,

chafing,
cracks,
twists and
loose
frame supports.

Hydraulic
tubing should be inspected for signs of
leakage (due to faulty flares or
loose
connections);

restrictions
(due to dents or corrosion); and wear (due to friction against other metal parts). Always
use correct type and size of wrench on fittings.

Avoid
damage to female fittings by supporting fit­
ting with tube nut during removal of assembly.

c.
On fittings where gaskets are used, always use
a
new gasket. Copper gaskets take a set and may
not form a
good
seal if reused.

d.
When replacing hydraulic brake hose, attach
hose
to wheel cylinder and securely tighten hose,
then attach
opposite
end to frame fitting or tubing.
Avoid
twists in
hose
when assembling to frame fitting
or
tubing. Hold
hose
end securely with

wrench
while attaching tubing to hose. If
hose
end
clip
is used, make certain clip is assembled properly.

Check
for interference during spring deflection or
rebound and during front wheel turns.

e.
Check
for any possible contact between front

brake
hose
and inner sidewall of tire when the front
wheels are in maximum
turn
position.
Check
for sufficient but not excessive length of
hose
between
the clamp and the wheels by turning the wheels
from
one extreme
turn
position to the otherl
f.
Check
that there is no possibility of any contact between the
tail
pipe and
rear
brake
hose
under
all
operating conditions.
P-9.
Brake Pedal Adjustment

There
should always be at least W [12,7 mm.]
free pedal travel before the push rod
engages
the master cylinder piston.

This
adjustment is accomplished by shortening or 326