recommended oil OPEL GT-R 1973 Service Manual

LUBRICATION AND MAINTENANCE OC-7SERVICESLUBE AND GENERAL MAINTENANCE
Vehicle operation under conditions such as heavy
dust, continuous short trips, use of other than un-
leaded or low lead fuels or pulling trailers, is not
considered normal use and therefore more frequent
maintenance will be required. Such additional
maintenance requirements are included where appli-
cable.
Engine OilChange each 4 months or
3,COO miles, whichever
occurs first, or each 2 months or
3,ooO miles when
the vehicle is operated under the following condi-
tions: (a) driving in dusty conditions, (b) trailer pull-
ing, (c) extensive idling or (d) short-trip operation at
freezing temperatures (with engine not thoroughly
warmed-up).Engine oils have a definite effect on ease of starting,
oil economy, combustion chamber deposits and en-
gine wear. It is recommended that a” oil which,
according to the label on the can is; (1) intended for
service SE and (2) passes car makers’ tests be used.
Oils confotming to these types contain detergent ad-
ditives. -
Select the proper oil viscosity from Figure OC-3.
Engine Oil FilterReplace at the first oil change and every other oil
change thereafter using Part No. 7965051 or equiva-
lent.
ChassisLubricate transmission shift linkage, hood latch and
parking brake cable guides and linkage.
Fluid LevelsCheck level of fluid in brake master cylinder, battery,
engine, axle, transmission and windshield washer.
Engine coolant also should be checked for proper
level and for corrosion and freeze protection to at
least -20°F or to the lowest temperature expected
during the period of vehicle operation. Proper engine
coolant also provides corrosion protection.
Any significant fluid loss in any of these systems or
units could mea” that a malfunction is developing
and corrective action should be taken immediately.
A low fluid level in the brake master cylinder front
reservoir could also be a” indtcator that the disc
brake pads need replacing.
The engine oil should be maintained at proper level.
The best time to check it is before operating the
engine or as the last step in a fuel stop. THIS WILL
ALLOW THE NORMAL OIL ACCUMULA-
TION IN THE ENGINE TO DRAIN BACK IN
the crankcase. To check the level, remove the oil
gauge rod (dipstick), wipe it clean, and reinsert it for
a” accurate reading. The oil level should be main-
tained in the safety margin, neither going above the
“FULL” mark “or below the “ADD OIL” mark.
See Figure OC-4.
DIP STICK MUST BE
INSERTED TO STOP
---L- -FULL+, 1 OT. ,-ADD
OIL
Figure OC-4 Engine Oil Dipstick
All models are equipped with tandem brake cylin-
ders. Maintain fluid level between MIN and MAX
marks on reservoir. See Figure OC-5. When adding
fluid use Delco Supreme No. 11 or equivalent.
TiresTo equalize wear, rotate tires as illustrated in Figure
OC-6.Adjust clutch when necessary as indicated by the
clutch warning lamp on Opel 1900 and Manta or

IoC-91973 OPEL SERVICE MANUAL
Figure OC-5 Brake Master Cylinder
I
Figure OC-6 Tire Rotation Methods
when the clutch pedal has in excess of 1
l/4 inch fr&
travel. See Figure OC-7.
Rear Axle
Change lubricant every
12,ooO miies when vehicle is
used for pulling a trailer.
Cooling SystemCheck at 12-month or
12,000~mile intervals, wash
radiator cap and filler neck with clean water, pres-
sure test system and radiator cap for proper pressure
holding capacity (tighten hose clamps and inspect
condition of all cooling and heater hoses). Replace
hoses every 24 months or 24,000 ,miles or earlier :if
checked, swollen or otherwise deteriorated.
Also each 12 months or
12,ooO miles, clean exteribr
of radiator core. Every 24 months or
24,OCO miles,Floor-Pan
-Clutch Pedal
Figure OC-7 GT Clutch Lash
drain, flush, and refill the cooline svstem with a new
coolant so&ion of permanent
6~; anti-freeze and
water for protection-of -20°F.
D-6 NOT REMOVE
RADIATOR CAP WHEN SOLUTION IS HOT
AND UNDER PRESSURE.
Wheel BearingsClean and repack front wheel bearings with a lubri-
cant as specified on the lubrication chart, Figure
oc-1.
Automatic Transmission FluidUnder normal driving conditions, change the trans-
mission fluid every 24,000 miles. Under unusual con-
ditions such as constant driving in heavy city traffic
during hot weather, trailer pulling, etc., this service
should be performed at
12,COO mile intervals.
General Motors DEXRON Automatic Transmis-
sion Fluid, which has been especially formulated and
tested for use in your automatic transmission, is
recommended. Other automatic transmission fluids
identified with the mark DEXRON are also recom-
mended.
Check the fluid level at each engine oil change
period. To make an accurate fluid level check:
1. Drive car several miles, making frequent starts and
stops, to bring transmission up to normal operating
temperature (approximately
180-190’F.)2. Park car on a level surface.
3. Place selector lever in “Park” and leave engine
running.

CC-10 1973 OPEL SERVICE MANUAL
wiper blades. Check amount and direction of fluid
sprayed by washers during use.,
E. Defrosters - Check performance by moving con-
trols to “DEF” and noting
am$nmt of air directed
against the windshield.
I
F. Wheel Alignment and
Balabce - In addition to
abnormal tire wear, the need fbr wheel alignment
service may be indicated by a pull to the right or
!eftwhen driving on a straight and level road. The need
for wheel balancing is usually
iddicated by a vibra-
tion of the steering wheel or
se;+ tihile driving at
normal highway speeds.I
IG. Brakes
- Be alert to illumiriation of the brake
warning light or changes in braking action,
SUCK as
repeated pulling to one side, unusual sounds when
braking or increased brake pedal travel. Any of thesecould indicate the need for
brakk system inspection
and/or service.
H. Parking Brake and Transmission “PARK”
Mechanism
- Check parking brake holding ability by
parking on a fairly steep hill and restraining the vehi-
cle with the parking brake only.
eon cars with auto-
matic transmissions, check the holding ability of the
“PARK” mechanism by releasing all brakes after
the transmission selector lever hak been placed in the“P” position.
I. Glass
- Check for broken, scrritched, dirty or da-
maged glass on vehicle that
coulld obscure vision’or
become an injury hazard.
J. Lights and Buzzers
- Check all instrument panel
illuminating and warning lights,’ seat belt reminder
light and buzzer, ignition key
b&er, interior lights,
license plate lights, side marker! lights, headlamps,
parking lamps, tail lamps, brake lights, turn signals,
backup lamps, and hazard warding flashers. Have
someone observe operation of
&ach exterior light
while you activate the controls: The operation of
instrument panel warning lights is covered in the
“Starting and Operating“ section of your
Own&%
Manual.K. Transmission Shift Indicator
‘- Check to be sure
automatic transmission shift
indiCator accurately i”-
dicates the shift position selected.
I
CAUTION: Before making thk check below,I
be sure to have a clear dist&e ahead and:
behind the car, set the parking brake and
firmly apply the foot brake.
Do not depress
accelerator pedal. Be prepared to
turn off ’
ignition switch
immediat+y if engine
should start.L. Starter Safety Switch (Automatic Transmissibn
Cars)
- Check starter safety switch by placing the
transmission in each of the driving gears while
at-tempting to start the engine. The starter should oper-ate only in the Park (“P”) or Neutral (“N”)
positions.
M. Horn
- Blow the horn occasionally to be sure thatit works. (Ignition switch must be in the “ON” posi-
tion.)
N. Seat Back Latches
- Check to see that seat back
latches are holding by pulling forward on the top of
each folding seat back.
0. Rearview Mirrors and Sun Visors
- Check that
friction joints are properly adjusted so mirrors and
sun visors stay in the selected position.
P. Door Latches
- Check for positive closing, latch-
ing and locking.
Q. Hood Latches - Check to make sure hood closesfirmly by pressing on the hood at the latching point
after each closing. Check also for broken, damaged
or missing parts which might prevent secure latch-
ing.R. Fluid Leaks
- Check for fuel, water, oil or other
fluid leaks by observing the ground beneath the vehi-cle after it has been parked for a while. If gasoline
fumes or fluid are noticed at any time, the cause
should be determined and corrected without delay
because of the possibility of fire.
S. Exhaust System
- Be alert to any change in the
sound of the exhaust system or a smell of fumes
which may indicate a leak.
Head Restraints
- Check that no head restraint
components are missing, damaged or loose. (Does
not apply to GT Models).
Disc BrakesCheck brake pads and condition of rotors while
wheels are removed during tire rotation. (Note belowregarding more frequent checks also applies to disc
brakes.)
Parking and Drum BrakesCheck drum
brake linings and other internal brake
components at each wheel (drums, wheel cylinders,
etc.). Parking brake adjustment also should be
checked whenever drum brake linings are checked.
NOTE: More frequent checks should be
made if driving conditions a.nd habits result
in frequent brake application. When brakes
require relining, it is recommended thatyou use those genuine General Motors
parts specified for your car,and Delco fluid
as required.

1F. 46 1973 OPEL SERVICE MANUAL
’
/
Headlight High-Low Beam Control and Passing:
SignalI
When the headlights have been switched on, high
and low beam selection is made by raising the direc-
tional signal lever toward steering wheel. Each
ti&the lever is raised, beam position, will change.
When the headlights are not on, a flashing headlight
signal may be given by raising and lotiering the di-
rectional signal lever. With the headlights on and
inlow beam position, raising and lowering the direc-
tional signal lever will also cause the headlights to
flash.
Fog Light SwitchAll Rallye models are equipped with two white f?g
lights mounted below the front bumper.
The fog light toggle switch is located on the
insty-ment cluster to the left of the temperature and
fuelgauge cluster.
/
The fog lights can be turned off at any time by the
toggle switch, but can only be tyrned on when: :
1. The ignition switch on or the
?gine running.!
2. The fog light toggle switch lower half is pushed
in.3. The parking lights and/or low beam headlights
are
OKThe fog lights are automatically turned off if the
ignition switch is on and the headlights are switched
to high beam position.
Courtesy LightThe courtesy light illuminates the interior of the Car
when any door is opened. The courtesy light can also
be turned on with all doors closed by tilting the l&s.
GT Headlamp MechanismThe concealed headlamps are moved mechanically.
Pushing actuating lever on left side of console opens
headlamps and pulling lever closes headlamps. Two
(2) meshing gear segments convert the movement, of
the lever to a rotation of 180 degrees. The pivots of
the headlamps lie below the centerline so that with
headlamps in closed position, the headlamp housing
is flush with front sheet metal. Refer to Group 110,
Section “F”, for service procedures on the GT head-
lamp mechanism.
A white indicator lamp in the instrument panel lights
if the headlamps are not completely opened lorclosed The switches of the headlamp electrical sys-
tem are located behind the left headlamp operating,
mechanism.
MAINTENANCE AND ADJUSTMENTSHEADLAMP AIMING
The headlamps must be properly aimed in order to
obtain maximum road illumination and safety that
has been built into the headlighting equipment. With
the Guide T-3 type sealed beam units, proper aiming
is even more important because the increased range
and power of this lamp make even slight variations
from recommended aiming hazardous to approach-
ing motorists. The headlamps must be checked for
proper aim whenever a sealed beam unit is replaced
and after an adjustment or repairs of the front end
sheet metal assembly.
Regardless of method used for checking headlamp
aim, car must be at normal weight, that is, with gas,
oil, water, and spare tire. Tires must be uniformly
inflated to specified pressure. If car will regularly
carry an unusual load in rear compartment, or a
trailer, these loads should be on car when headlamps
are checked. Some States have special requirements
for headlamp aiming adjustment, and these require-
ments should be known and observed.
Horizontal and vertical aiming of each seal beam
unit is provided by two adjusting screws which move
the mounting ring in the body against the tension of
the coil spring. There is no adjustment for focus,
since the sealed beam unit is set for proper focus
during manufacturing assembly.
MAJOR REPAIRHEADLIGHT SWITCH
- OPEL 1900. MANTA
Removal1. Remove instrument cluster cover panel. See Sec-
tion H.
2. Compress retaining springs and pull switch out.
See Figure 1 F-
1.3. Pull multiple socket off switch.
Installation
1: Plug multiple socket in switch and push switch in
panel until clips lock in place.
2. Replace instrument cover and secure with two (2)
screws.

I2A- 21973 OPEL SERVICE MANUAL
GENERAL INFORlVlATION
CONTENTS
SubjectPage No.
DESCRIPTION AND OPERATION: (Not Applicable)
DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
PaintMaintenance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2A-2
ChromeMaintenance
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2A-2
StainRemoval
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2A-2
MAJOR REPAIR: (Not Applicable)
SPECIFICATIONS:
Bolt
TorqueSpecifications. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2A-4
Special Body Tools
. . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2A-5
MAINTENANCE AND ADJUSTMENTSPAINT MAINTENANCE
To remove heavy concentrations of road dirt and
grime, it is recommended that the car be washed
using an automotive shampoo or mild soap, and cold
to lukewarm water. Use of harsh soaps or detergents
is not advised. In areas where salt is used on the
roads during the winter months, more frequentwashing is recommended.
Use of cleaners and polishes are required if no high
luster is obtainable by waxing. To protect the paint
finish, sparingly apply several coats of wax. Each
coat should be thoroughly rubbed to remove any
surplus wax.
Once the car is properly waxed, road dirt may easily
be removed by use of cold to lukewarm water and a
sponge. Dry by use of a chamois.
CHROME MAINTENANCE
Chrome parts should be washed with water and a
mild detergent. If rust or salt corrosion should ap-
pear, they may be removed with Buick Rust Eraser
or equivalent. Do not use scouring powders or stiff
brushes.STAIN REMOVAL
Before attempting to remove spots or stains from
upholstery fabrics, determine as accurately as possi-
ble: (1) Nature and age of the spot or stain. (2) The
affect of stain removing agents on the color, struc-
ture and general appearance of the fabric.
For best results, stains should be removed from
upholstery as soon as possible after they have been
made. If they are allowed to stand for some time,
they often become set, and removal becomes more
diffxult and frequently impossible.
There are three basic types of acceptable’ cleaners
available to car owners: (1) Volatile cleaners, (2) Syn-
thetic detergents, (3) Neutral soap (non-alkaline).
The volatile cleaners are recommended since they
have great solvent powers for grease, oils and general
road grime. Synthetic detergents generally loosen
stains satisfactorily, however, the use of improper
type detergents (containing bleach) involves risk of
damage to the color or finish of fabrics.
Precautions For Cleaning FabricsDo not use laundry soap or detergents containing
bleaches. The use of these agents tends to weaken
fabric and to change its color. Do
not use too much
cleaning fluid. Some interior trim assemblies are pad-

fabric to dry thoroughly; then rub lightly with a
clean cloth dipped in a volatile cleaner. This is the
only further treatment recommended.
Soap and water are not recommended since they will
probably set the stain and cause a permanent dis-
coloration. Drying the fabric by means of heat (such
as the use of an iron) is not recommended.
6. Grease and 02 If grease has been spilled on the
material, as much as possible should be remove by
scraping with a dull knife or spatula before further
treatment is attempted.
Grease and oil stains may be removed by rubbing
lightly with a clean cloth saturated with a volatile
cleaner. Be sure all motions are toward the center of
the stained area to decrease the possibility of spread-
ing the stain.
7. Ice Cream. The same procedure is recommended
for the removal of ice cream stains as that used in
removing fruit stains.
If the stain is persistent, rubbing the spot with a cloth
wet with soap suds (mild neutral soap) may be used
to some advantage after the initial treatment with hot
water. This soap treatment should be followed with
a rinsing, by rubbing with a clean cloth wet with cold
water. After this dries, rubbing lightly with a cloth
wet with volatile cleaner will clear up the last of the
stain, by removing fatty or oily matter.
8.Vomit. Sponge with a clean cloth, dipped in clear
cold water. After most of the stain has been removed
in this way wash lightly with soap (mild neutral),
using a clean cloth and lukewarm water. Then rub
with another clean cloth dipped in cold water. If any
of the stain remains after this treatment, gently rub
clean with a cloth moistened with a volatile cleaner.
SPECIFICATIONS
BOLT TORQUE SPECIFICATIONSLocation
DoorStriker toPillarPostr .^ ...r.ZA- 41973 OPEL SERVICE MANUAL
9. Shoe Polish and Dressings. On types of shoe
dressing which contain starch or dextrine or some
water soluble vehicle, allow the polish to dry; then
brush the spot vigorously with a brush. This will
probably be all the treatment that is necessary. If
further treatment is required moisten the spot with
cold water and after it has dried, repeat the brushing
operation.
Paste or wax type shoe polishes may require using a
volatile cleaner. Rub the stain gently with a cloth wet
with a volatile cleaner until the polish is removed.
Use
;a clean portion of the cloth for each rubbing
operation and rub the stained area from outside to
center.
10. Tar. Moisten the spot lightly with a volatile
cleaner, and then remove as much of the tar as possi-
ble with a dull knife. Follow this operation by rub-
bing the spot lightly with a cloth wet with the cleaner
until the stain is removed.
II. .X&e. Sponge the stain with a clean cloth satu-
rated with soap suds (mild neutral soap) and rinse
well by rubbing the stain with a clean cloth dipped
in cold water. Then saturate a clean cloth with a
solution of one part household ammonia water and
five parts water. Apply the cloth to the stain and
allow solution to remain on affected area for one
minute; then rinse by rubbing with a clean wet cloth.
I,?.
L,ipslick. The compositions of different brands of
lipsticks vary, making the stains very
diff%cult to
remove. In some instances a volatile cleaner may
remove the stain. If some stain remains after re-
peated applications of the volatile cleaner, it is best
to leave it rather thari try other measures.
Torque
Lb.Ft.
wont saar twacnment to war........................................Seat andShoulderBelt Anchor Attachment
................StationwagonTailgate
HingetoBody............................StationwagonTailgate
HingetoDoor............................Stationwagon Striker Plate on
Body................................Stationwagon
LatchHookonBody..................................Stationwagon Latch on Door
............................................14.18
_^ _^13-1036-46
13-16
13-16
3-4
13-16
3-4

ROOF AND SUN ROOFZF-25ConditionCallseCorrectionSun roof lifts up on one
side only.Lifter wedge welded to under-
Remove sun roof panel and bend
side of sun roof panel doeslifter wedge so that it squarely hits
not run up ramp welded inramp. The only adjustment for
center of sun roof track.the ramp is the angle of the
rear portion. This should be
adjusted so that the wedge smoothly
rides up the ramp.
Transporter cable or drive
pinion damaged.If the transporter cable is worn
or damaged, replace both
cables. If drive pinion worn or
damaged, replace drive pinion and
also both transporter cables.
Sun roof scrapes on car roof
when closing sun roof.Lifters do not lie flat.Close sun roof, slide sun roof
frame to the rear and open and close
sun roof slightly noting operation
of lifters. Rework if necessary,plastjc lifter cushion with tile
to permit lifter to lie flat.
Sparingly lubricate lifter guide.
Sun roof frame becomes
detached.Attaching clips have lost
elasticity.Install new clips
Water enters car interior.
Water drain hoses blocked.
Bent water drain hoses
Rear water drain hoses have
been pulled out of rubber
grommets.
Velvet strips on front and
rear of sun roof do not seal
properly.Clean hoses with compressed air
or a flexible steel cable.
NOTE: To clear rear water
drain hoses, the sun roof panel
and frame must be removed.
Blowing out of rear drain hoses
from trunk compartment hose end
is not recommended due to
possibility of soiling car
interior.
Attempt to straighten drain
hoses by working a suitable
tube or cable through hose.
Replace hose if above corrective
action is not satisfactory.
Apply a small amount of rubber
cement to rear water drain
hoses and reinsert into rubber
grommet located in luggage
compartment floor panel.
Check sun roof for correct
height adjustment. If height
adjustment is correct, but a
tight seal does not exist,
relocate velvet strip upward
for better seal, or replace
velvet strip.

DRUM BRAKESBC- 29
at a time to avoid getting fluid level in reservoir
dangerously low. The correct sequence for bleeding
is bleed the wheel cylinder or caliper nearest the
master cylinder first in either circuit.
Do not perform bleeding operation while any brake
drum is removed.
Bleeding Wheel Cylinder or Caliper
1. Check fluid level, in reservoir and refill, if neces-
sary. Level must be brought up to “MAX” mark on
plastic reservoir.
2. Clean all dirt from around respective bleeder
valve, and then remove cap.
3. Push bleeder hose over bleeder valve, placing
other end of hose in a glass jar. Bleeder hose should
always be used to avoid getting fluid on linings.
4. Hold pressure on brake pedal and crack open the
bleeder valve to allow air (and,or) brake fluid to flow
out of the system. Allow pedal to travel to the floor.
Close bleeder valve. Release pedal and repeat this
procedure at each wheel cylinder in the circuit until
all air is removed. Frequently check reservoir fluid
level. Allowing fluid to be emptied will draw air into
the system.
5. Remove bleeder hose and install cap.
6. When bleeding operation is completed, make sure
that fluid level is brought up to “MAX” marking on
reservoir, then install cover.
7. Discard the brake fluid deposited in glass jar dur-
ing bleeding operation.
Flushing Brake Hydraulic System
It is recommended that both brake system circuits be
thoroughly flushed whenever the master cylinder is
replaced or if there is any doubt as to the grade of
fluid in the system.
Flushing of the brake system is performed in the
same manner as the bleeding operation except that
fluid is forced through the lines and wheel cylinder
until it emerges clear in color. Approximately one
half pint of brake fluid is required to flush the hy-
draulic system thoroughly.
When flushing is completed, make certain the master
cylinder reservoir is filled to the proper level.Figure
5C-52 Rear Drum Brake Assembly
MAJOR REPAIR
REPLACE OR RELINE BRAKE SHOES
(DRUM BRAKES)Removal and Inspection
1. Jack up car in safe manner and support ade-
quately.
2. Remove wheel and drum assembly.
3. Remove upper and lower brake shoe return
springs.
4. Remove retaining pins and springs, as shown in
Figure
5C-52.5. Clean all dirt out of brake drum. Inspect drums
and replace or recondition if required.
6. Blow all dirt from brake assemblies and inspect for
any unusual condition.
7. Carefully pull lower edges of wheel cylinder boots
away from cylinders and note whether interior is wet
with brake fluid. Fluid at this point indicates leakage
past piston cup, requiring overhaul or replacement of
wheel cylinder.
8. Inspect all brake pipe and hose connections for
evidence of fluid leakage. Tighten any leaking con-
nection, then apply heavy pressure to brake pedal
and recheck connections.
9. Inspect backing plate for oil leak past rear wheel
bearing oil seals. Correct any leak by installation of
new seals.

Figure 5C-53 Rear Brake Assembly
10. Check all backing plate attaching bolts to make
sure they are tight. Using line emery cloth, clean all
rust and dirt from shoe contact surfaces on plate. See
Figure Z-53.
Relining Brake ShoesIf old brake shoes are to be relined, inspect shoes for
distortion and for looseness between the rim and
web; these are causes for discarding any shoe. If
shoes are serviceable, be governed by the following
points in installing new linings:
1. Remove old rivets by drilling them out. Punching
out rivets will cause distortion of shoe rim. Care5C- 301973 OPEL SERVICE MANUAL
must also be taken to support shoes properly while
drilling.
2. Thoroughly clean brake shoes and remove all
burrs around rivet holes.
3. Use Opel brake lining or equivalent. Install in
place and rivet in sequence shown in Figure
Z-54.Keep hands clean while handling brake lining. Do
not permit oil or grease to come in contact with
lining.
Installation and Adjustment
1. If any hydraulic conne&tions were disturbed, bleed
hydraulic system. If new parts were installed in
brake system, flushing of hydraulic system is recom-
mended.
2. Adjust rear wheel brakes.
3. Adjust parking brake.
4. Check fluid level in master cyliner and add fluid
if necessary.
5. Check brake pedal for proper feel and for proper
return.
6. Remove jacks and road test car for proper brake
action. Brakes must not be severely applied immedi-
ately after installation of new brake shoes or linings.
Severe application may perinanently injure new lin-
ings and may score brake drums. When linings are
new, they must be given moderate use for several
days until burnished.
INSPECTING AND RECONDITIONING
BRAKE DRUMSWhenever brake drums are removed, they should
bethoroughly cleaned and inspected for cracks, scores,
deep groves, and out-of-round. Any of these condi-
tions must be corrected since they can impair the
efficiency of brake operation and also can cause
premature failure of other parts.
Cracked, Scored or Grooved DrumA cracked drum is unsafe for further service and
must be replaced. Welding a cracked drum is not
recommended.
Smooth up any slight scores by polishing with tine
emery cloth. Heavy or extensive scoring will cause
excessive brake lining wear and it will be necessary
to rebore in order to true up the braking surface.
Figure 5C.54 Brake Lining Riveting
SequenceIf the brake linings are slightly worn and drum is
grooved, the drum should be rebored just enough to

DRUM BRAKES5c- 31
remove grooves, and the ridges in the lining should
be lightly removed with a lining grinder.
If brake linings are more than half worn, but do not
need replacement, the drum should be polished with
fine emery cloth but should not be rebored. At this
stage, eliminating the grooves in drum and smooth-
ing the ridges on lining would necessitate removal of
too much metal and lining, while if left alone, the
grooves and ridges match and satisfactory service
can be obtained.
If brake linings are to be replaced, a grooved drum
should be rebored for use with oversize linings. A
grooved drum, if used with new lining, will not only
wear the lining but will make it
diff%xlt, if not im-
possible, to obtain etXcient brake performance.
Out-of-Round DrumAn out-of-round drum makes accurate brake shoe
adjustment impossible and is likely to cause excessive
wear of other parts of brake mechanism due to its
eccentric action. An out-of-round drum can also
cause brake pulsation. Maximum permissible drumrunout is 004”. A drum that has more run-out than
this should be rebored. Runout can be accurately
checked by using an inside micrometer fitted with
proper extension rods.
When measuring a drum for run-out, take measure-
ments at open and closed edges of machined surface
and at right angles to each other.
Turning Brake DrumsIf a brake drum is to be turned, enough metal should
be removed to obtain a true, smooth braking surface.
Measure brake drum diameter; standard drum inner
diameter is 9.060”. Drums may be turned to an over-
size of ,030”. If maximum inner diameter after turn-
ing exceeds 9.090”, brake drum will have to be
replaced. Removal of more metal will affect dissipa-
tion of heat and may cause distortion of the drum.
1. Remove rear wheels and drums.
2. Mount brake drum on brake drum lathe and turn
drums as necessary, within limits.
3. After turning, check drum diameter. Inner diame-
ter not to exceed 9.090.
4. A newly-bored drum should always have center
contact with brake shoes. For this reason, arc grind
linings to
.OlO” under drum radius, or to ,020” under
drum diameter.
5. Clean and install drums and wheels.
BRAKE WHEEL CYLINDER OVERHAUL1. Remove wheel, drum, and brake shoes. Be careful
not to get grease or dirt on brake lining.
2. Disconnect brake pipe or hose from wheel cylinder
and cover opening with tape to prevent entrance of
dirt. Remove wheel cylinder from backing plate.
3. Remove boots, pistons, cups, and spring from cyl-
inder. Remove bleeder valve.
4. Discard rubber boots and piston cups. Thoroughly
clean all other parts with hydraulic brake fluid orDeclene. Do not use anti-freeze, alcohol, gasoline,
kerosene, or any other cleaning fluid that might con-
tain even a trace of mineral oil.
5. Inspect pistons and cylinder bore for scores, scrat-
ches, or corrosion. Light scratches may be polished
with crocus cloth. Do not use emery cloth or sandpa-
per.
Shght corro~on may be cleaned wth tine steel
wool. If scratches or corroded spots are too deep to
be polished satisfactorily, the cylinder should be re-
placed since honing is not recommended.
6. Dip internal parts in brake fluid and reassembly
wheel cylinder. When installing piston cups, use care
to avoid damaging the edges.
7. If the rear wheel backing plate is removed: Always
install new paper gaskets one on each side
- on the
backing plate. Prior to installation, lightly coat paper
gaskets with chassis lubricant. Torque backing plate
to rear axle housing bolts to 43
lb.ft. and wheel brake
cylinder to backing plate bolts to 5
lb.ft. Install wheel
cylinder on brake backing plate and connect brake
pipe or hose.
8. Install brake shoes, drum, and wheel, then flush
and bleed hydraulic system.
9. Adjust brakes, then road test car for brake per-
formance.
CAUTION:This brake backing plate to rear axle fis-
tener is an important attaching part in that it could
affect the performance of vital components and sys-
tems, and/or could result in major repair expense. It
must be replaced with one of the same part number
or with an equivalent part, if replacement becomes
necessary. Do not
use a replacement part of lesser
quahty or substitute design. Torque v&es must be
used as specified during reassembly to assure proper
retention of this part.
REPLACING BRAKE PIPESAny brake pipe assembly which is needed must be
made up from service bulk tubing and fittings. All
brake pipes must be made of tin or copper coated
wrapped steel tubing with the ends double lap flared.