1953 JEEP DJ air conditioning

'Jeep*
UNIVERSAL
SERIES SERVICE
MANUAL

D
straight
in the hole, then tap the dowel lightly

with
a hammer until it
bottoms.

d.
When installing bearing eaps, be sure to tighten
the
bolts
evenly in each cap to
pull
it into place
without bending the
dowels
or distorting the
bearing
cap.
e. Other parts of the block which require inspec­ tion
and
possible
repair,
but which are directly
related
to other
engine
components (such as tappets, pistons, camshaft, valves, crankshaft, and

oil
pump) are covered later in this section.

D-35.
Cylinder
Bores

The
cylinder bores may be reconditioned by honing
or
reboring. Use oil-soaked rags to protect
crank­

shaft
journals
and other
engine
parts from abrasive
dust during all reconditioning operations.

Both
honing and reboring of the cylinders must be
done
carefully to fit the pistons and to obtain
specified clearances. If reboring of the cylinder bores is not required but the walls are glazed, use

a
finishing
hone
to remove the glaze. Reboring the cylinders must not be attempted unless ade­
quate facilities and experienced service technicians
are
available. The amount of material to be re­moved is determined from the original diameter
of the cylinder bores (3.125" to 3.127") [79,375 a
79,426
mm.] plus the amount of oversize in diameter
of the oversize pistons to be fitted. Pistons are
available
in the following oversizes.
.010"
[0,254
mm.] .030" [0,762 mm.] .020" [0,508 mm.] .040" [1,016 mm.}

The
largest cylinder bore
will
determine the over­
size to which all cylinders must be rebored, since the size and weight of all pistons must be uniform
to maintain proper
engine
balance. The maximum rebore should not exceed .040" [1,016 mm.] from

standard.
Measure
the cylinder diameters by making mea­
surements both parallel to and at right angles to
crankshaft
over entire piston travel and at
bottom

of cylinder. Proceed as follows:

a.
If bores are scored; if out-of-round
exceeds
.005
"
[0,127 mm.]; if diameters differ more than .005";

or
if taper
exceeds
.005
"
on diameter, it is generally
recommended that cylinders be reconditioned by
reboring
and honing to the next oversize using new
pistons of the proper size.

Note:
If reboring is performed, allow .0015"
[0,0381
mm.] for final honing.

All
cylinder bore diameters must be within .002
"
[0,0508
mm.] after reconditioning.

b.
If bore measurements are within the above

limits,
but indicate hollows or waviness, cylinders should be honed with 250 grit
stone
hone. Pump
hone
up and down in cylinder while it is rotating
to produce a satin-finish, diamond cross-hatched

pattern
approximately 30° with horizontal. Hone
only enough to correct waviness.
c. If cylinder bore correction is unnecessary, break the glaze on cylinder walls with a 250 grit
stone

hone
or with a suitable deglazing tool. Operate the
hone
or deglazer to obtain diamond cross-hatched

pattern
previously mentioned.

d.
Regardless of type of correction on cylinder
walls,
wash out bores thoroughly afterwards and
apply
a light coat of
engine
oil. If cylinders have
been rebored or honed heavily, measure cylinder
diameters again to assure proper selection of piston
size.

D-36.
Pistons, Rings, and Connecting Rods
Pistons are each fitted with three rings, two com­ pression rings and one oil control
ring.
The pistons have an extra
groove
above the top ring which acts as a heat dam or insulating
groove
to protect
against sealing of the top ring in the ring
groove

with
hard
carbon. The piston pin is secured by the lock screw.

The
pistons and connecting rods were removed from
the
engine
as assemblies. If cylinders were rebored,
new oversized pistons and rings
will
have to be in­

stalled.

Disassemble the pistons and rods. Remove the
two compression rings, the oil control
ring,
and the oil control ring expander from each piston. Do not remove the
bolts
from the lower end of the
connecting rods unless the
bolts
are damaged.
Clamp
each connecting rod and piston assembly

in
a padded bench vise and remove the piston pin

lock
screw and lockwasher. Press the piston pin
out of the piston and connecting rod.
Clean
all
carbon,
gum, and lacquer
deposits
from both the

inner
and outer surfaces of each piston, connecting

rod,
and piston pin. Use a ring
groove
cleaner or a
broken
ring filed to a sharp square
edge
to clean
the carbon from the piston ring
grooves
and the

insulator
groove. Use care not to scrape metal from
the sides of the
grooves
or make
burrs
on ring
groove
surfaces. Run a length of wire through the

oil
spray
hole
near the lower end of the connecting

rod
to clear the
hole
of hardened oil
deposits
or
foreign matter.
Carefully
inspect the pistons and
replace
any that are broken or cracked. Replace
pistons if any of the ring lands are chipped, broken,
or
rounded on the
edges;
or if the piston is scored,

scratched,
or burned so seriously that the imperfec­
tions cannot be removed with a hand honing
stone

or
crocus cloth.

Replace
the pistons as follows:

a.
After cylinder bores have been carefully checked for out-of-round and taper (Par. D-35), check fit
of each piston to cylinder bore with block and
pistons clean and dry and at approximately 70
°F.
[21°C]
by using Piston Fitting Gauge And Scale

Tool
No. C-690 as shown in Fig. D-7. Use a .003"
[0,0762
mm.] thickness
gauge
%" [19 mm.] wide.

The
piston is fitted upside down in the block to
facilitate the operation. The
gauge
must extend the
full
length of the piston on the thrust side
(opposite

side from slot in piston
skirt).
Scale should register
5
to 10 pounds [2,3 a 4,5 kg.]
pull
to remove the
thickness
gauge
from
between
cylinder
wall
and piston. Excessive
pull
indicates need for a slightly

smaller
piston or additional honing of cylinder. In­ sufficient
pull
indicates need for fitting a larger piston. 47

'Jeep*
UNIVERSAL SERIES SERVICE
MANUAL

P
f. On vehicles without a transmission brake hold
the brake
shoes
in their relative position and
engage
the parking brake cable
into
the parking

brake
lever.
g. On vehicles without a transmission brake in­
stall
the parking brake strut and spring
between

the parking brake lever and the primary
shoe.

h.
Place the brake
shoes
on the backing plate and

install
the retainer pins, springs and retainers.

i.
Install the anchor pin plate.

j.
Install the lever and
sleeve
on the primary
shoe
then install the secondary return spring, then the
primary
return spring.

Important:
A
"L"
or "R" is located on the hex­

agon
side of the lever crank for identification. The
lever crank marked "R" applies to the primary
shoe
on the
left
rear brake assembly. The lever
crank
marked
"L"
applies to the primary
shoe
on
the right rear brake assembly.
k. Place the upper linkage rod in the
groove
of the
anchor pin and
engage
the hook of the link rod
into

the adjusting lever.

I.
Install the brake drum. Install the wheel and

tire
assembly.
m. Adjust the brakes as described
below.

P-19.
Brake
Shoe
Initial
Adjustment —

a.
Should wheel brake units have
been
disassem­ bled for any reason, an initial adjustment
MUST
be made
before
drum installation.

b.
When the brake parts have
been
installed in
their correct position, initially adjust the adjusting
screw assemblies to a point where approximately Y% [9,53 mm.] of threads are
exposed
between
the

star
wheel and star wheel nut.

Note:
Following the initial adjustment and final
assembly, check brake pedal height to ensure

brake
operation. Then drive the car in reverse and
FIG.
P-12—BRAKE SHOE ADJUSTMENT
1—
Star
Wheel
2—
Lever

3—
Screwdriver
4—
Brake
Adjusting Tool
forward,
making 10 to 15 brake applications prior
to road testing.
This
action balances the adjust­
ment of the four brake units and raises the brake
pedal.
c. Adjustment may be made manually by remov­ing the access
slot
cover and using a brake adjust­
ing
tool
or screw driver to rotate the star wheel
until
the wheel is in the locked position. To tighten, rotate the star wheel in the clockwise direction.
Then
back off the star wheel at least 15 to 20

notches
(clicks).

d.
To back off the star wheel on the brake, insert
ice pick or thin blade screw driver in adjusting screw
slot
to hold lever away from adjusting screw.

Back
off on adjusting screw until wheel and drum

turn
freely. Replace adjusting
hole
cover.

Caution:
DO NOT attempt to back off on ad­
justing screw without holding adjuster lever away from screw as adjuster
will
be damaged.
P-20. Master Cylinder Reconditioning —
Dual
System

Refer
to Fig. P-13.

DISASSEMBLY
a.
Remove the filler cap and empty all fluid.
b.
Remove the snap ring, push rod assembly, and
the primary and secondary piston assemblies. Air pressure applied in the piston
stop
hole
will
help
facilitate the removal of the secondary piston as­
sembly.
c. The residual check valves are located under
the front and rear fluid
outlet
tube
seats.

d.
The
tube
seats
must be removed with the
self-

tapping screws supplied in the repair kit to permit removal of the check valves. Screw the self-tapping
screws
into
the
tube
seats
and place two screw

driver
tips under the screw head and force the
screw upward as shown in Fig. P-14.
e. Remove the expander in the rear secondary cup, secondary cups, return spring, cup protector,
pri­

mary
cup, and washer from the secondary piston.
f. The primary piston, with the rubber cups in­ stalled, is supplied in the repair kit.

CLEANING
a.
After disassembly, immersion of all metal parts
in
clean brake fluid or a brake system cleaner is
recommended. Use air
hose
to blow out dirt and cleaning solvent from recesses and internal pas­

sages.
When overhauling a hydraulic brake unit,
use all parts furnished in the repair kit. Discard
all
old rubber parts.

b.
After cleaning, place
all"
hydraulic
system parts
on clean paper or in a clean pan.

INSPECTION
Inspect all other parts for damage or
excessive

wear.
Replace any damaged, worn, or chipped
parts.
Inspect hydraulic cylinder bore for
signs
of
scoring, rust, pitting, or etching. Any of
these
will
require
replacement of the hydraulic cylinder. 331

'Jeep'
UNIVERSAL
SERIES SERVICE
MANUAL

P h.
Install
the tube seats, flat side toward the check

valve,
and press in with tube nuts or the master

cylinder
brake pipe tube nuts.

BLEEDING
a.
Before the master cylinder is installed on the
car,
the unit must be bled.

b.
Support the cylinder assembly in a vise and

fill
both fluid reservoirs with approved brake fluid,

e.
Loosely install a plug in each
outlet
of the

cylinder.
Depress the push rod several times until

air
bubbles cease to appear in the brake fluid.

d.
Tighten the plugs and attempt to depress the piston. The piston travel should be restricted after
all
air is expelled.
e.
Install
the master cylinder on the car and bleed
the hydraulic lines at the wheel cylinder. Refer to
Par.
P-7.

P-21.
Wheel
Cylinder
Reconditioning
•
Refer to Fig. P-15.
Note:
Make sure a replacement brake cylinder
has the same part number as the original cylinder.

FIG.
P-15—WHEEL
BRAKE CYLINDER
1— Boot

2—
Piston

3—
Cylinder
Cup
4—
Cup
Spring
5—
Cylinder

6—
Bleeder
Screw
a.
To remove a wheel cylinder,
jack
up the vehicle

and
remove the wheel, hub, and
drum.
Disconnect
the brake line at the fitting on the brake backing
plate. Remove the brake
shoe
return spring which

will
allow the brake
shoes
at the toe to
fall
clear of the brake cylinder. Remove two screws holding
the wheel cylinder to the backing plate.
b.
Remove the rubber dust covers on ends of

cylinder.
Remove the pistons and piston cups and
the spring.

c.
Wash the parts in clean alcohol.

d.
Examine the cylinder bore for roughness or
scoring.
Check
fit of pistons to cylinder bore.
e. When reassembling the cylinder, dip springs, pistons and piston cups in brake fluid.
Install

spring
in center of the wheel cylinder.
Install

piston cups with the cupped surface towards the

spring
so that the flat surface
will
be against
the piston.
Install
pistons and dust covers.
f.
Install
wheel cylinder to the backing plate and connect brake line and install brake
shoe
return

spring.

g. Replace wheel, hub, and
drum.

h.
Bleed the brake lines (Par. P-7).

P-22. TROUBLE
SHOOTING

P-23.
Squeaky
Brakes

In
most cases, squeaks are entirely eliminated by

correct
adjustment of the brakes. Squeaks may be
caused however, by glazed linings, lining wore thin
to the point of
exposed
rivets or by vibration. A

drum
will
not vibrate when the brake is securing

uniform
contact over the entire lining surface, ex­
cept when due to improper conditions such as the
linings becoming glazed.
Glazed
surface of the

brake
linings may be removed by a stiff
wire
brush.
Occasionally
squeaks are caused by roughened
sur­

face of the
drum,
which can usually be remedied
by rubbing down with emery cloth and by wiping
the brakings surface clean. In extreme cases it may
be necessary to reface the drum in a lathe. Should
this be done, do not remove a metal thickness greater than .030" [0,762 mm.] - .060" [1,52 mm.]

overall
diameter.

P-24. Rattles
in
Brakes

See that the tension of the springs in the brakes

and
attached to the control system are sufficient to

return
brakes and brake mechanism to their normal
position.
Return
springs are so placed that they
keep all slack out of the control system by tension on all joints.

Brakes
will
not rattle inside the
drum
if the springs
holding the
shoes
are kept at the proper tension. 333