DODGE TRUCK 1993 Service Repair Manual

5
- 44
BRAKES

• Check rotor lateral runout and thickness variation
if pedal pulsation or an occasional low pedal condi­
tion was experienced. Measure runout with a dial in­
dicator. Measure thickness with a micrometer at a
minimum of four points around the braking surfaces.
The rotor measurement points are shown in Figure
17.
Fig. 17 Rotor Measurement
Points
CHECKING ROTOR MINIMUM THICKNESS
Measure rotor thickness at the center of the brake-
shoe contact surface. Replace the rotor if it is worn
below minimum thickness, or if refinishing would re­ duce thickness below the allowable minimum. Rotor
minimum thickness is usually specified on the rotor

hub.

ROTOR THICKNESS VARIATION Variations in rotor thickness will cause pedal pul­
sation, noise and shudder.
Measure rotor thickness at 6 to 12 points around
the rotor face (Fig. 18). Position the micrometer ap­
proximately 25.4 mm (1 in.) from the rotor outer cir­ cumference for each measurement (Figs. 17 and 19). Thickness should not vary by more than 0.025 mm
(0.001 in.) from point-to-point on the rotor. Refinish
or replace the rotor if necessary.
ROTOR RUNOUT Check rotor lateral runout with Dial Indicator
C-3339 (Fig. 18). Excessive lateral runout will cause
brake pedal pulsation and rapid, uneven wear of the
brakeshoes.
Position the dial indicator plunger approximately
25.4 mm (1 in.) in from the rotor edge. Be sure
wheel bearing end play is reduced to zero before
checking runout. Maximum allowable runout is 0.127 mm (0.005 in.).
Fig. 18 Checking Rotor Runout And
Thickness
Variation

ROTOR REFINISHING Rotor braking surfaces can be refinished by sand­
ing and/or machining in a disc brake lathe. The lathe
must be capable of machining both rotor surfaces si-

•

BRAKES
5 - 45 multaneously with dual cutter heads. Equipment ca­
pable of machining only one side at a time will
produce a tapered rotor. The lathe should also be equipped with a grinder
attachment or dual sanding discs for final cleanup or
light refinishing.
If the rotor surfaces only need minor cleanup of
rust, scale, or scoring, use abrasive discs to clean up
the rotor surfaces. However, when a rotor is scored or
worn, machining with cutting tools will be required.

CAUTION:
Do not refinish a rotor if
machining

would
cause
the rotor to
fall
below minimum allow­
able
thickness.

ROTOR REMOVAL
(1) Raise and support front of vehicle.
(2) Remove wheel and tire assemblies.
(3) Remove support key retaining screw (Fig. 6).
(4) Remove caliper support key and spring with
pin punch or drift (Fig. 19).

Fig.
19
Removing
Caliper
Support
Key And
Spring
(5) Remove caliper and brakeshoes from adapter.
Do not allow brake hose to support caliper
weight. Support caliper on stool, or secure cali­
per to nearby frame or chassis component with
wire.
(6) Remove hub cap. (7) Remove drive flange snap ring with Tool
C-4020 (Fig. 20).
(8) Remove flange nuts and lock washers and re­
move drive flange. Discard the flange gasket.
(9) Straighten tang on lock ring. (10) Loosen outer locknut and adjusting nut with
Tool DD-1241-JD (Fig. 19). Then remove outer lock- nut, lock ring, inner adjusting nut and outer bearing. (11) Remove hub and rotor from spindle.
Fig.
20
Removing
Drive Flange
Snap
Ring

(12) Remove seal and inner bearing from hub if
bearing or seal requires service.
(13) If wheel bearing races require service, remove
them with suitable remover tools or with brass drift. (14) Clean rotor and hub and wheel bearings in
solvent.

ROTOR
INSTALLATION
(1) Repack wheel bearings and coat spindle with
Mopar high temperature bearing grease. (2) Install new bearing races, bearings and seals in
hubs if necessary. (3) Install hub on spindle and install outer bearing
and inner adjusting nut. (4) Tighten adjusting nut to 68 Nrni (50 ft. lbs.)
with Special Tools DD-1241-JD and C-3952 to seat
bearings. (5) Adjust wheel bearings as follows: (a) Back off adjusting nut.
(b) Retighten adjusting nut to 54 N*m (40 ft. lbs.)
while rotating hub and rotor. (c) Back off adjusting nut approximately 135 to
150 degrees. (d) Install lock ring and locknut.
(6) Tighten lock nut to a minimum of 88 N»m (65
ft. lbs.). Bearing end play should be 0.025 - 0.25 mm (0.001 - 0.010 in.). (7) Bend one tang of lock ring over adjusting nut
and another tang over locknut to secure them. (8) Install new gasket on hub and install drive
flange, lock washers and nuts. Tighten nuts to 41 - 54 N«m (30 - 40 ft. lbs.). (9) Install flange snap ring with Tool C-4020.
(10) Install hub cap.
(11) Install caliper and brakeshoes. Tighten sup­
port retaining screw to 20 Nnn (15 ft. lbs.) torque. (12) Install wheel and tire assembly and lower ve­
hicle.

i - 46
BRAKES

• DRUM
BRAKES—ELEVEN
INCH

INDEX
page
Brake Drum Inspection
and
Refinishing
........ 48

Brake Drum
Installation
.................... 48

Brake Drum Removal
46

Brake
Shoe
Installation
. 47

Brake Support
Plate
Installation
49
Brake Support
Plate
Removal
............... 49
page
Brakeshoe Removal
...................... 46

Cleaning
and
Inspection
47

General
Information
46

Wheel Cylinder
Installation
50
Wheel Cylinder Overhaul
49

Wheel Cylinder Removal
49

GENERAL
INFORMATION
Chrysler eleven inch rear drum brakes are used on
D and W150 models (Fig. 1). All applications are two
shoe,
internal expanding units with a self adjuster
mechanism. A single wheel cylinder is used to ex­
pand the dual brakeshoes. The lower ends of the
brake shoes are connected by a star wheel adjusting screw which is part of the self adjusting mechanism.

SUPPORT PLATE PARKING

BRAKE

STRUT
AND
SPRING RETURN
SPRING ANCHOR
PLATE RETURN CABLE
SPRING GUJDE
PRIMARY
SHOE
AND
LINING

SHOE SPRING
ADJUSTER SCREW
ASSEMBLY
ADJUSTER
LEVER LEVER
SPRING PARKING

BRAKE
LEVER
ADJUSTER CABLE AND
SPRING
SHOE
RETAINER, SPRING
AND
PIN

SECONDARY SHOE
AND
LINING
J9005-62

Fig.
1 Eleven
Inch
Drum
Brake
Assembly

BRAKE
DRUM REMOVAL
(1) Raise and support vehicle. (2) Remove wheel and tire.
(3) Remove clip nuts securing brake drum to wheel

studs.
(4) If drum is difficult to remove, retract brake-
shoes as follows: (a) Remove rear plug from access hole in support
plate. (b) Insert a thin screwdriver into access hole and push self adjusting lever away from adjuster screw
star wheel. (c) Insert Tool C-3784 into brake adjusting hole
and rotate adjuster screw star wheel to retract
brakeshoes.
(5) Remove brake drum.
(6) Inspect brakelining for wear, alignment, or ev­
idence of leakage from axle or wheel cylinder.

BRAKESHOE
REMOVAL
(1) Remove rear wheel and drum.
(2) Remove shoe return springs with Tool C-3785
(Fig. 2).
SHOE
RETURN SPRING SPECIAL
TOOL

(REMOVING
AND
INSTALLING)
SHOE
TO SHOE

SPRING LEVER
SPRING
ADJUSTING
LEVER
RH225A

Fig.
2 Removing/Installing
Shoe
Return
Springs
(3) Remove adjuster cable. Slide cable eye off an­
chor pin and remove cable from adjuster lever.
(4) Remove cable guide from secondary shoe and
remove anchor plate from anchor pin. (5) Remove adjuster lever. Disengage lever from
spring by sliding lever forward to clear pivot and
work lever out from under spring.
(6) Remove adjuster lever spring from pivot.
(7) Disengage and remove shoe spring from brake-

shoes.

BRAKES
5 - 47
(8) Disengage and remove adjuster screw assembly
from brakeshoes.
(9) Remove brake shoe retainers, springs and pins
with Tool C-4070, (Fig. 3). Fig. 3 Removing/Installing Shoe Retainers, Springs
and Pins (10) Remove secondary brakeshoe from support
plate. (11) Remove strut and anti rattle spring (Fig. 4).
Fig. 4 Removing/Installing Strut And Spring
(12) Remove parking brake lever from secondary

shoe.

(13) Remove primary shoe from support plate.
(14) Disengage parking brake lever from parking
brake cable.

CLEANING AND INSPECTION
Clean the brake components, including the support
plate and wheel cylinder exterior, with a water dampened cloth or with Mopar brake cleaner. Do not
use any other cleaning agents and do not use com­
pressed air to remove dirt and dust. Replace the brakeshoes if worn to within 1.5 mm
(1/16 in.) of the rivet heads or if bonded lining is less
than 4 mm (3/16 in.) thick. Examine the lining con­
tact pattern to determine if the shoes are bent or the drum is tapered. The lining should exhibit contact across the entire width. Shoes exhibiting contact only
on one side should be replaced and the drum checked
for runout or taper.
Clean and inspect the adjuster screw assembly. Re­
place the assembly if the star wheel threads are damaged, or the components are severely rusted or corroded.
Discard the brake springs and retainer components
if worn distorted, or collapsed. Also replace the springs if a brake drag condition had occurred. Over­
heating will distort and weaken the springs. Inspect the brakeshoe contact surfaces on the sup­
port plate (Fig. 5). Remove light rust and scale from
these surfaces with 180 grit emery cloth or sandpa­
per. However, replace the support plate if any of the contact surfaces are worn or rusted through. Also re­
place the plate if it is bent or distorted.
Fig. 5 Shoe Contact Surfaces

BRAKE
SHOE INSTALLATION
(1) Lubricate anchor pin and brakeshoe contact
pads on support plate (Fig. 5) with Mopar multi-pur­

pose,
or high temperature grease. (2) Lubricate adjuster screw socket, nut, button
and screw thread surfaces with Mopar multi purpose,
or high temperature grease. (3) Attach parking brake cable to lever. Then con­
nect lever to secondary shoe. (4) Install primary shoe on support plate. Secure
shoe with new spring retainers and pin (Fig. 6). (5) Install spring on parking brake strut and en­
gage strut in primary shoe (Fig. 6). (6) Install secondary shoe on support plate (Fig. 6).
Insert strut in shoe and guide shoe onto anchor pin.
Temporarily secure shoe with retaining pin. (7) Install anchor plate and adjuster cable eyelet
on support plate anchor pin.

5
- 48
BRAKES

•

Fig.
6
Brakeshoe
Installation
(8) Install cable guide in secondary shoe and posi­
tion cable in guide. (9) Assemble adjuster screw (Fig. 7). Then install
and engage adjuster screw in brakeshoes.

CAUTION:
Be sure the
adjuster
screws
are in­

stalled
on the
correct
brake unit. The
adjuster

screws
are marked L
(left)
and R
(right)
for
identifi­

cation
(Fig. 8). ' WASHER SOCKET
STAMPED
LETTER

BUTTON
NUT
RH227A
Fig.
7 Adjuster
Screw
Components
(10) Install adjuster lever and spring and connect
adjuster cable to lever.
(11) Install secondary shoe retainers and spring.
(12) Install shoe spring. Connect spring to second­
ary shoe first. Then to primary shoe. (13) Verify adjuster operation. Pull adjuster cable
upward. Cable should lift lever and rotate start
wheel. Be sure adjuster lever properly engages start
wheel teeth.
(14) Adjust brakeshoes to drum with brake gauge.
Refer to Service Adjustments section for procedure.

BRAKE
DRUM
INSPECTION
AND
REFINISHING
BRAKE DRUM REFINISHING The brake drums can be resurfaced on a drum
lathe when necessary. Initial machining cuts should
be limited to 0.12 - 0.20 mm (0.005 - 0.008 in) at a
time as heavier feed rates can produce taper and sur­ face variation. Final finish cuts of 0.025 to 0.038 mm
(0.001 to 0.0015 in.) are recommended and will gen­
erally provide the best surface finish.
Be sure the drum is securely mounted in the lathe
before machining operations. A damper strap should always be used around the drum to reduce vibration
and avoid chatter marks.
BRAKE DRUM REFINISH LIMITS The maximum allowable diameter of the drum
braking surface is stamped or cast into the drum outer edge (Fig. 8). Generally, a drum can be ma­
chined to a maximum of 1.52 mm (0.060 in.) oversize.
Always replace the drum if machining would cause
drum diameter to exceed indicated size limit.
Fig.
8 Location Of Brake
Drum
Maximum Allowable
Diameter BRAKE DRUM RUNOUT
Measure drum diameter and runout with an accu­
rate gauge. The most accurate method of measure­
ment involves mounting the driim in a brake lathe
and checking variation and runout with a dial indi­
cator. Variations in drum diameter should not exceed
0.076 mm (0.003 in.). Drum runout should not exceed 0.20 mm (0.008 in.) out of round. Refinish the drum
if runout or variation exceed these values.

BRAKE
DRUM
INSTALLATION
(1) Clean drum with Mopar brake cleaning solvent
or with a soap and water solution only. Do not use any other cleaning agents and do not use compressed
air to remove dirt and dust.

•

BRAKES
5 - 49 (2) Adjust brake shoes to drum with a brake
gauge. (3) Install and secure drum to wheel studs with
new retaining nuts/clips.
(4) Install rubber access plugs in support plate if
removed.
(5) Install wheel and tire.

BRAKE
SUPPORT PLATE REMOVAL
(1) Remove wheel and tire and brake drum.
(2) Remove axle shaft and retainer. Refer to Group
3 for procedures. (3) Remove primary brakeshoe for access to park­
ing brake cable if necessary. (4) Compress parking brake cable retainer tabs
with a hose clamp (Fig. 9). Then push retainer and cable through and out of support plate.
AIRCRAFT TYPE

HOSE
CLAMP
RB763

Fig.
9
Removing
Parking Brake Cable From
Support
Plate
(5) Disconnect brake line at wheel cylinder.
(6) Remove wheel cylinder and brakeshoes from
support plate.
(7) Remove bolts attaching support plate to axle
and remove support plate.

BRAKE
SUPPORT PLATE INSTALLATION
(1) If new support plate is being installed, apply
bead of Mopar silicone sealer around wheel cylinder mounting surface. Then transfer wheel cylinder to
new support plate. (2) Apply bead of Mopar silicone sealer around
axle mounting surface of support plate. (3) Install support plate on axle flange. Tighten at­
taching bolts to 47-68 N-m (35-50 ft. lbs.). (4) Install parking brake cable in support plate.
(5) Install axle shaft and retainer.
(6) Start brakeline in wheel cylinder and install
cylinder on support plate. Tighten brakeline fitting after cylinder installation. (7) Connect parking brake cable to lever on sec­
ondary shoe and install brakeshoes on support plate.
(8) Adjust brakeshoes to drum with brake gauge.
(9) Install brake drum and wheel and tire.
(10) Bleed brake system.

WHEEL CYLINDER REMOVAL
(1) Raise vehicle and remove wheel and brake
drum. (2) Disconnect wheel cylinder brakeline.
(3) Remove brakeshoe return springs and move
shoes out of engagement with cylinder push rods. (4) Remove cylinder attaching bolts and remove
cylinder from support plate.

WHEEL
CYLINDER OVERHAUL
WHEEL
CYLINDER DISASSEMBLY
(1) Remove push rods and boots (Fig. 10).
(2) Press pistons, cups and spring and expander
out of cylinder bore.
(3) Remove bleed screw.
SPRING

CYLINDER PISTON
CUP
CUP

EXPANDERS
BOOT
PISTON
'

BLEED
SCREW PUSH
ROD '
J9005-66

Fig.
10
Wheel
Cylinder
Components
CLEANING
AND
INSPECTION

Clean the cylinder and pistons with fresh brake
fluid or brake cleaner only. Do not use any other cleaning agents. Dry the cylinder and pistons with
compressed air. Do not use rags or shop towels to dry
the cylinder components. Lint from such materials
can adhere to the cylinder bores and pistons.
Inspect the cylinder bore. Light discoloration and
dark stains in the bore are normal and will not im­
pair cylinder operation. If desired, the bore can be lightly polished but only with crocus cloth. Replace
the cylinder if the bore is scored, pitted or heavily
corroded. Honing the bore to restore the surface is
not recommended.
Inspect the cylinder pistons. The piston surfaces
should be smooth and free of scratches, scoring and
corrosion. Replace the pistons if worn, scored, or cor­
roded. Do attempt to restore the surface by sanding or polishing.

5
- 50
BRAKES

• Discard
the old
piston cups
and the
spring
and ex­

pander. These parts
are not
reusable.
The
original
dust boots
may be
reused
but
only
if
they
are in
good condition.

ASSEMBLING
WHEEL
CYLINDER
(1) Lubricate wheel cylinder bore, pistons, piston
cups
and
spring
and
expander with clean brake fluid. (2) Install first piston
in
cylinder bore. Then
in­

stall
cup in
bore
and
against piston.
Be
sure
lip of

piston
cup is
facing inward (toward spring
and

expander)
and
flat side
is
against piston.
(3) Install spring
and
expanders followed
by re­
maining piston
cup and
piston.
(4) Install boots
on
each
end of
cylinder
and
insert
push rods
in
boots.

(5)
Install cylinder bleed screw.

WHEEL
CYLINDER INSTALLATION
(1) Apply bead
of
Mopar silicone sealer around cyl­
inder mounting surface
of
support plate. (2) Connect brake line
to
cylinder. Mount cylinder
on support plate
and
install cylinder attaching bolts. (3) Install wheel brake components.
(4) Install brake drum
and
wheel
and
bleed
brakes.

DRUM
BRAKES—TWELVE INCH

INDEX

page

Brake Drum
Installation
54

Brake Drum Removal
52

Brake Drum Service
54

Brake
Shoe
Installation
53

Brakeshoe
Removal
52

Cleaning
and
Inspection
52

GENERAL
INFORMATION
Twelve inch rear drum brakes
are
used
on D and

W 250/350 models
(Fig. 1). All
applications
are
dual
shoe,
internal expanding units with
a
self adjusting
mechanism.
A
single wheel cylinder
is
used
to ex-
page
General
Information
50

Support
Plate
Installation
55

Support
Plate
Removal
55

Wheel
Cylinder
Installation
55
Wheel
Cylinder
Overhaul
...................
54

Wheel
Cylinder
Removal
. 54

pand
the
dual brakeshoes.
The
lower ends
of the

brake shoes
are
connected
by a
star wheel adjuster screw which
is
part
of the
self adjusting mechanism
(Fig.
1).

SHOE
HOLD-

DOWN
PIN

WHEEL
CYLINDER PRIMARY SHOE UPPER
SHOE-TO-SHOE SPRING

SHOE
HOLD-DOWN SPRING
LOWER-SHOE-TO-SHOE
SPRING

ANTI-RATTLE
SPRING

FLAT
WASHER
ANCHOR BOLT WHEEL CYLINDER BOLTS
ADJUSTING
HOLE COVER ANCHOR
BOLT NUT
SHOE
HOLD-

DOWN
PIN
BACKING PLATE

AUTOMATIC
ADJUSTER
CABLE

ADJUSTER LEVER
PIVOT
PIN

SECONDARY
SHOE
PARKING

BRAKE
LEVER ADJUSTER LEVER
RETURN SPRING

AUTOMATIC

ADJUSTER LEVER
RN326A

Fig. 1
Twelve
Inch
Drum
Brake
Assembly

5
- 52
BRAKES

•
BRAKE
DRUM
REMOVAL

(1) Raise and support vehicle.
(2) Remove wheel and tire assembly.
(3) Remove axle shaft nuts, washers and cones.
Strike axle shaft in center with copper or dead blow
hammer to loosen retaining cones.
(4) Remove axle shaft.
(5) Remove outer hub nut.

(6)
Straighten and remove lock washer.
(7) Remove inner nut and bearing.
(8) Remove drum. If drum is difficult to remove,
retract brakeshoes as follows: (a) Remove rear plug from access hole in support
plate. (b) Insert a thin releasing tool (or screwdriver)
into access hole and push self adjusting lever away
from adjuster screw star wheel (Fig. 2). (c) Insert thin screwdriver, or Tool C-3784 into
access hole and rotate adjuster star wheel to re­
tract brakeshoes (Fig. 2).
Fig.
2 Retracting
Brakeshoes

(9) Remove brake drum.
(10) Inspect brakelining for wear, alignment, or
evidence of leakage from axle or wheel cylinder.

BRAKESHOE
REMOVAL
(1) Unhook adjuster lever return spring from lever
(Fig. 1). (2) Remove lever and return spring from lever
pivot pin (Fig. 1). (3) Unhook adjuster lever from adjuster cable as­
sembly (Fig. 1). (4) Remove shoe-to-shoe upper spring (Fig. 3).

(5)
Remove shoe holddown springs (Fig. 4).

(6)
Disconnect parking brake cable from parking
brake lever. (7) Remove both brakeshoes, shoe-to-shoe lower
spring and adjuster nut as assembly (Fig. 5). (8) If support plate or wheel cylinder are to be ser­
viced, remove anchor bolt and nut that attaches
parking brake lever to support plate. Then remove
RK60A

Fig.
3 Removing/Installing
Shoe-To-Shoe
Upper
Spring

Fig.
4 Removing/Installing
Shoe
Holddown
Springs

lever, washer, spring, cam plate, anchor bolt bushing and adjuster cable (Fig. 1).
CLEANING AND INSPECTION

Clean the brake components, including the support
plate and wheel cylinder exterior, with a water dampened cloth or with Mopar brake cleaner. Do not
use compressed air. Replace the brakeshoes if the lining is worn to
within 1.5 mm (1/16 in.) of the rivet heads or if
bonded lining is less than 4 mm (3/16 in.) thick. Ex­ amine the lining contact pattern to determine if the
shoes are bent or the drum is tapered. The lining
should exhibit contact across the entire width. Shoes
exhibiting contact only on one side should be re­
placed and the drum checked for runout or taper.

•

BRAKES
5 - 53

Fig.
5 Removing/installing
Brakeshoes
Clean and inspect the adjusting nut and pivot
screw assembly. Replace the assembly if the star
wheel threads on the nut are damaged, or the screw are severely rusted or corroded.
Discard the brake springs and retainer components
if worn distorted, or collapsed. Also replace the
springs if a brake drag condition had occurred. Over­
heating will distort and weaken the springs.
Inspect the brakeshoe contact pads on the support
plate (Fig. 6). Remove light rust and scale from the
pads with fine sandpaper. However, replace the sup­
port plate if any of the pads are worn or rusted
through. Also replace the plate if it is bent or dis­
torted. Fig. 6
Support
Plate
Brakeshoe
Contact
Pads
BRAKE
SHOE
INSTALLATION

(1) If parking brake lever was removed, install an­
chor bolt bushing, cam plate, lever, spring, washer
and anchor bolt and nut (Fig. 1). (2) Coat contact pads on support plate (Fig. 6) with
Mopar high temperature grease, or equivalent, (3) If both sets of brakeshoes were removed, verify
that adjusting nuts are installed on correct side of vehicle. Pivot screw and adjusting nut have left hand
threads on left side brake assembly and right hand
threads on right side assembly.
(4) Lubricate and assemble adjusting nut and pivot
screw.
(5) Assemble adjusting nut, shoe-to-shoe lower
spring and both brakeshoes. Then position the as­
sembled components on the support plate.
(6) Install brakeshoe holddown springs and pins
(Fig. 4). Be sure holddown pins are seated in support
plate and springs are connected as shown (Fig. 7).
SHOE
HOLD
DOWN
PIN

HOLD DOWN
SPRING

BACKING PLATE
RN1064

Fig.
7
Holddown
Spring
And Pin Attachment (7) Connect parking brake cable to parking brake
lever. Be sure cable end is properly secured in lever
(Fig. 8).
Fig.
8
Connecting
Parking Brake Cable
(8) Install shoe-to-shoe upper spring (Fig. 3).
(9) Position adjuster lever return spring on pivot.
(10) Install adjuster lever.