1988 PONTIAC FIERO Service Repair Manual

28-4 BUMPERS
1-STOP RlNG
2-SEAL 3-FLOATING PISTON
4-HYDRAULIC FLUID FILLED
CYLINDER TUBE ASSEMBLY
5-MOUNTING STUD
6-METERING PIN
7-CYLINDER TUBE
8-ORIFICE
9-PISTON SEAL
10-FRAME BRACKET
11-PISTON TUBE
12-BUMPER BRACKET
13-SEALING BALL
14-GAS-FILLED PISTON
TUBE ASSEMBLY
15-STOP RlNG
16-CYLINDER TUBE ASSEMBLY
17-HYDRAULIC FLUID
18-PISTON TUBE ASSEMBLY
19-FLOATING PISTON
20-DRILL AREA TO RELIEVE
GAS PRESSURE
21 -GAS m
COLLAPSED
Fig. 1 Energy Absorbing Device
ON-VEHICLE SERVICE
1 -PLATE ASM
2-BAR ASM
3-NUT
4-SH
I M
5-RIVET
6-ABSORBER
Fig.
60 1 Absorber and Bar Asm.

BUMPERS 28.5
TORQUE SPECIFICATIONS
Rear bumper fascia
to quater
pailel
Front and rear bumper
bar to body

CHASSIS SHEET METAL 2C-1
SECTION %C
CHASS S SHEET METAL
NOTICE: These fasteners are important attaching parts in that they could affect the performance of vital
parts and systems,
andlor could result in major repair expense. They 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
quality or substitute design. Torque values must be used as specified during reassembly to assure proper retention
of all parts. There is to be no welding as it may result in extensive damage and weakening of the metal.
For prevailing torque
nut(s) and bolt(s), refer to the "Reuse of Prevailing Torque Nut(s) and Bolt(s)" chart in
Section OA.
CONTENTS
............................... General Description 2C-1
.............................................. Fasteners 2C- I
.......................... Anti-Corrosion Materials 2C- 1
................................ Service Procedures 2C-1
..................................... Hood Assembly 2C-1
.......................................... Hood Hinge 2C-2
........................................... Hood Latch 2C-2
......................................... Fender Panel 2C-3
.............................. Molding Replacement 2C-3
Aluminum Panel Repair Procedures
............. 2C-3
PaintingIRepairing Non-Metal Parts ............. 2C-3
RepairingIRefinishing Urethane
Bumpers and Front End Panels
................. 2C-4
.............................. Paint Color Matching 2C-5
Proper Identification and Painting of
............................. Interior Plastic Trim.. 2C-6
....................................... Test Procedure 2C-6
Painting Interior Plastic Parts
..................... 2C-6
...................... Polypropylene Plastic Parts .2C-6
Rigid or Hard Plastic Parts ....................... 2C-7
Vinyl and Flexible ABS Parts
.................... 2C-7
On-Vehicle Sewice ................................ 2C-7
GENERAL DESCRIPTION
FASTENERS SERVICE PROCEDURES
Many aluminum components are used in the
current models. Aluminum in contact with steel may
corrode rapidly if not protected by means of special
finishes or isolators.
Many of the fasteners used in the front sheet
metal area have the new GM
6174M finish which will
provide adequate protection. In some places, how-
ever, special fasteners are used in conjunction with
aluminum components. These special fasteners are
argent silver in order to more easily identify them
from the standard metric fasteners which are a
medium blue in color.
When replacing fasteners in the front sheet
metal area, it is advisable to avoid substitution of
otherwise similar fasteners in locations which should
use GM
6174M type fasteners or special fasteners for
aluminum components.
NOTICE: Failure to follow this precaution may
result in premature corrosion of the sheet metal in
the areas mentioned above.
ANTI-CORROSION MATERIALS
Anti-corrosion materials have been applied to
the interior surfaces of some metal panels to provide
rust resistance. When servicing these panels, areas on
which these materials have been disturbed should be
properly
recoated with service-type anti-corrosion
material.
HOOD ASSEMBLY
The hood is composed of a single outer panel
and an inner panel reinforcement. The hood may be
either steel or aluminum.
Adjust
Figure 1
Slotted holes are provided at all hood hinge
attaching points for proper adjustment
- both verti-
cally and fore and aft. Vertical adjustment at the front
may be made by adjusting rubber bumpers up and
down. For best appearance, make one adjustment at a
time.
TO RAISE OR LOWER THE REAR comers of
the hood for proper alignment to the fenders, and to
insure contact with the hood side wedges, proceed as
follows:
1. Loosen hinge-to-hood attaching screws.
2. Reposition hood assembly.
3. Tighten hinge-to-hood attaching screws to
specifications.
4. If necessary, repeat procedure on opposite side
of hood.

26-2 CHASSIS SHEET METAL
TO RAISE OR LOWER THE FRONT comers
for proper alignment, proceed as follows:
1. Close hood firmly.
2. Determine the amount of adjustment necessary.
3. Open hood.
4. Raise or lower the adjustable hood bumpers as
required.
FORE AND APT adjustment can be accom-
plished as follows:
1. Loosen hinge to fender attaching screws.
Remove or Disconnect
Open hood.
Scribe line on hood inner panel and fender panel
to indicate original hinge position.
Block hood on side where hinge is to be
removed.
Prop hood open.
Remove hinge-to-hood attaching screws and
hinge-to-fender attaching screws.
Carefully remove hinge and strut assembly.
- -
2. Reposition hinge assembly. install or Conned 3. Tighten hinge to fender attaching screws to
specifications. 1. Mount new hinge on fender using scribed line
4. If necessary, repeat procedure on opposite side for location,
and tighten attaching screws.
of hood. 2.
Position hinge to hood using scribed line for
location, install attaching screws and tighten.
3. Carefully close hood and check for proper
- - alignment.
4. If hood is misaligned, measure amount of
mis-
Figure 7
Hood hinges are fastened to the fender panel.
The hold-open position is provided by a hood
hinge spring assist linkage assembly. This spring
assist linkage is comprised of a
single-am elbow joint
assembly combined with a small coil spring.
1-HINGE ASM.
2-BOLT/SCREW
Figure 1 Hood Hinge - Typical
alignment.
a. Open hood.
b. Loosen hinge at hood or fender and repo-
sition to correct misalignment.
c. Tighten hood-to-hinge attaching screws to
specifications and repeat alignment proce-
dure if necessary.
HOOD L14TCI-I
The hood latch is a cable released, positive lock-
ing hood latch assembly located in the radiator sup-
port and baffle assembly, and locks with the
hood-
mounted striker. The hood release handle is located
inside the car at the left side of the plastic shroud kick
panel. After the release handle has been pulled, the
hood can be fully opened by releasing the hand catch
on the hood underside.
1. Using a
13mrn (112") socket and ratchet with
114" drive, reach up between the outboard side
of the radiator and grille, and remove the two
hood release latch assembly retaining screws.
2. With the two screws removed, raise the hood.
3. With the hood up, the hood release latch assem-
bly can be removed.
4. Reassemble the hood latch assembly to the radi-
ator support assembly.
5. Replace or repair the hood release cable as
necessary.
After proper positioning of the hood bumpers,
hood height is automatically controlled by the verti-
cally self-adjusting hood latch assembly. Proper hood
alignment is essential for ease of latch operation.
Adjust
1. Loosen latch attaching bolts to finger-tight.
2. Push down on hood, holding the hood closed
while pulling the release lever.

CHASSIS SHEET METAL 2C-3
3. Allow hood to open, and tighten latch bolts in
new location.
FENDER PANEL
An outer fender panel with a plastic inner panel
is used. Care should be used in handling raw fenders
due to the lack of fender rigidity prior to installation.
Body surfaces at molding areas must be cleaned
thoroughly with suitable organic solvent immediately
prior to installation to ensure adhesion. Do not allow
adhesive surface of molding to come in contact with
wet solvent, dirt, or foreign matter.
NO"FICE: If heat source is used to condition
moldings prior to installation, the source is to
provide
uniform heating, not to exceed 85°F.
Application is to be made in a clean area with
ambient and body surface temperatures of at least
65°F.
The moldings are to be secured with two appli-
cations of a force of 20 pounds for the full length of
each section using a roller or other suitable tool.
Any section of molding removed once in contact
with the body surface must be replaced.
ALUMINUM PANEL REPAIR PROCEDURES
An aluminum hood (inner and outer panel) is
used on some vehicles. An aluminum panel can be
identified by checking it with a magnet, preferably in
the front corners to avoid any possible damage to the
paint. Aluminum will not attract a magnet.
Aluminum panels can be repaired successfully
with only slight changes of materials and techniques
commonly used to refinish steel panels. The necessary
modifications fall into two categories: 1) metal
preparation; and 2) painting.
Metal Preparation
1. Because aluminum is relatively easy to grind,
care must be taken not to use overly coarse abra-
sive discs or excessive grinder speeds (greater
than 2,000 rpm), both of which will cause
excessive heat and unnecessary metal removal.
2. Surface scratches should normally be removed
with 180 or 120 grit paper with scalloped edges.
Hand sanding with 80 grit paper will usually be
sufficient to remove excessive body filler or
heavy scratches, again followed with 180 grit
paper.
NOTICE: Avoid scratching aluminum when
sanding with 80 grit paper by hand.
3. Foam backed pads are recommended for
grinders used on aluminum, rather than the
stiffer rubber pads used for mounting abrasive
discs used on steel. The foam pad helps to
reduce heat build-up and improves blending for
feathering.
4. Localized heat, generated by grinding, can be
minimized by the use of a grease stick, such as
Formax F-160 or equivalent. This does, how-
ever, tend to load up the grinding discs quickly,
which should be periodically cleaned by rotating
them against a brush wetted with solvent.
5. If out-dings or minor convex defects need to be
filed, it is recommended to use a round edge,
double cut, flexible file with 22 teeth per inch
overlaid with 52 teeth per inch (such as
Nicholson
#50-412 or equivalent).
NOTICE: Keep file clean so that chips do not
scratch aluminum.
The use of heat is not recommended, since the
structural characteristics of aluminum are noticeably
affected by heat. A bent or buckled aluminum hood,
which exhibits strain cracks either before or after
straightening, should be replaced.
Both steel and aluminum panels can be metal
prepped and repaired with two-part polyester filler
materials in the same number of operations. The only
differences are that less aggressive type files and abra- sive discs should be used, with care being taken not to
overheat the aluminum.
Painting
Painting procedures for aluminum panels differ
very little from those used on steel panels. Two pre-
cautions should, however, be observed:
1. Alkaline base paint removers are not recom-
mended and should not be used.
2. Aluminum also requires a chemical cleaner such
as
DuPont 2253, Ditzler DX-533, or equivalent
be used on bare metal to remove contaminants
and corrosion. After cleaning, a conversion
coating such as DuPont
226S, Ditzler DX-503
or equivalent should be applied to promote
adhesion.
Beyond these considerations, painting alumi-
num panels should present no increases in difficulty or
changes in procedure and technique.
PAINTING AND REPAIRING NONMETAL
EXTERIOR PARTS 1
FiberglassIABS Plastic Panel Repair ~
A Plastic Solder Repair Kit can be used to repair
cracks, dents, or pits in fiberglass or ABS panels. A
Glass Woven Cloth should be installed on the under
side of a crack in the panel to structurally reinforce the
panel. The following procedure can be used to repair
the panels:
1. With a lacquer removing solvent, remove paint
from damaged area down to the fiberglass or
, ABS material. I
2. Scuff-sand area surrounding damaged area to
provide a good bonding surface.

2C-4 CHASSIS SHEET METAL
3. Clean area to be repaired.
4. Mix and apply the repair material by using a
putty knife or rubber squeegee.
5. Work the material into the repair and build up
the desired contour. For deep filling, and on
vertical surfaces, several layers may be
required.
6. Feather-sand damaged area with No. 200 sand-
paper and finish-sand with No. 320 sandpaper.
7. Prepare repaired area for refinishing. Refinish
with acrylic lacquer as described below.
1. THOROUGHLY CLEAN the entire surface
area, using Naphtha or equivalent solvent, to
insure a surface free of contamination.
2. To promote paint adhesion, a light scuff-sand-
ing of the surface with
#400-grit sandpaper is
recommended.
3. Repeat cleaning of the surface.
4. Color coat with acrylic lacquer for proper color
match.
5. Allow to dry thoroughly, rub out and polish.
PAINT REFINISHING PROCEDURES FOR
URETHANE, P.V.C. AND T.P.R. SURFACES
Urethane material will withstand minor impact
and the resultant damage, such as occurs in parking
lots, by recovering its original shape. Its Endura paint
film responds to impact in a similar manner without
cracking or splitting. If, however, an area of damage
in the Urethane bumper or panel does not recover its
shape, or the surface is punctured, gouged or torn, a
repair system has been developed to restore the origi-
nal shape and appearance of the urethane-base
material.
CALSVON: There are a number of paint
systems available For service use; how-
ever,
many require additives containing
isocyanates.
It is essential that all rec-
ommendations and warnings listed on
the container label for
materials
seleded be followed.
CAUTION: If the paint system selected
specifies an additive containing
isocya-
nates, it is mandatory that adequate
respiratory protection be worn. An
example of such protection
is an air line
respirator with a
full hood or half mask.
If not
avaiable, use a vaporlpaHiculate
respirator that the respirator supplier
recommends as
efFective for isocyanate
vapors and mists (unless local
regula-
tions prevail).
Such protection should be worn during the
entire painting process. Persons with respiratory
problems, or those
allergic to isocyanates must not
be exposed to isocyanate vapors or spray mist.
REPAIRING & REFINISHING URETHANE
BUMPERS AND FRONT END PANELS
Required Materials:
1. 3M No. 8101 Structural Adhesive, or
equivalent.
2. Color Coat - Dexlar (DuPont) Flexible Finish
Enamel Color Coat, or Ditzler Elastomeric
Enamel Color Coat or equivalent.
3. Additive
- DuPont 792s Centari Hardener,
or
Ditzler
DXR-80 Delthane Additive or
equivalent.
4. Thinner
- DuPont 3608s Acrylic
Lacquer
Thinner, or Ditzler Delstar DTR 601 Acrylic
Enamel Reducer or equivalent.
NOTICE: Use the same brand name materials for
the color coat, additive, and thinner.
5. A wax and adhesive cleaner.
Equipment Needed:
1. Wooden spatula (enclosed in repair package).
2. Heat lamp.
3. 36 grit 180-A, 240-A, and 320-A grit disc
sandpaper.
4. Random orbital-type sander.
5. Body repair tape.
6. Suction spray gun (same nozzle and air cap
combination as used for acrylic).
Repair Procedure
There are three types of repairable damage on
urethane material. They are a puncture, a gouge and a
tear.
Following is the basic repair procedure for
repairing these types of damages.
1. Clean the damaged area with 3M #8984 Gen-
eral Purpose Adhesive Cleaner or equivalent. If
the damage is through the thickness of the part,
clean both sides.
Grind away damaged material with a
36 grit
disc. Feather edge the paint around the damage
using a
1808 grit disc.
2. If the part has a puncture or tear, file or rout out
the area where joint line will be. Bevel the edge
of the part with the open edge towards the side
to be filled (fill from the side with easiest
access). Clean the repair area with a clean dry
rag.
3. Apply 3M #6935 Auto Body Repair Tape, or
equivalent, to the underside of the repair area to
backup the repair material.
NOTICE: Before going to the next step, be sure
all of the paint (both topcoat and primer) has been
removed from the area where the structural adhe-
sive is to be applied.

CHASSIS SWEET MEWL 2C-5
4. Mix 3M #05900 Structural Adhesive, or equiv-
alent, according to instructions on package. For
best results, use a 2-step application. First, mix
only enough for a thin coat.
Mix adhesive thoroughly with mixing stick
enclosed in package, or a putty knife. HINT: If
you use the mixing stick, bevel the edge to form
a straight, rather than a rounded surface.
5. Apply adhesive over entire area with a rubber
squeegee. Step A: Apply a light coat over entire
area and allow to dry. Step
B: Mix and apply the
contour. Spread from edges of repair towards
center, filling all low areas.
6. Hand level with surrounding area using a 240-A
grit disc. Check for voids and low areas. If nec-
essary mix up more adhesive and apply to low
areas.
Allow each coat of adhesive to dry before apply-
ing subsequent coats. Drying can be quickened
by application of low heat (for example, a low
power heat lamp). DO NOT OVERHEAT.
After final coat, sand using a 320-A grit disc.
7. Scuff-sand entire panel with a 320 grit disc by
hand or with a random orbital type sander. Wipe
entire area to be painted with a clean dry cloth
and/or tack cloth per paint manufacturer's
instructions.
8. Paint panel using Inmont R-M Alpha-Cryl, or
with R-M 891 Urethane Catalyst Flex Agent, or
the Ditzler Elastomeric Enamel Flexible Paint System (DE type), or equivalent urethane paint
systems. Follow label directions.
Coloring Procedure:
1. THOROUGHLY CLEAN the entire surface
area with
3919s Prepsol (DuPont) or equivalent
solvent to insure a surface
free of
contamination.
2. To promote paint adhesion and insure a smooth
surface, a light scuff-sanding with #400-grit
sandpaper (wet or dry) is recommended.
3. Repeat cleaning of the surface.
4. Mask off areas of car not to be painted using
masking tape and paper.
5. Thoroughly mix the color coat, additive and
thinner as suggested on the label directions.
NOTICE: Mix only that which is needed, noting
that pot life is 2-3 hours.
6. Using 35 lbs. of pressure at the gun, spray panel
with
2 or 3 coats (depending on the need) allow-
ing 2-3 minutes flash time between each coat.
Use a final mist coat for metallics.
7. Allow paint to cure 2-4 hours before handling.
8. COMPOUNDING reduces the gloss. For this
reason rubbing compound should be used
only
if a reduction of gloss is desired.
PAINT COLOR MATCHING
If a color coat mismatch between the original
color and the repair material is encountered during
paint repair, a closer color match can be accomplished
by following these recommendations. Assistance may
also be solicited from the manufacturing repre-
sentative of the paint supplier.
1. Stir the paint thoroughly both before and after
thinning.
2. If the repair is too light and metallic looking
after spraying a couple of coats, it can be dark-
ened by spraying
several wet coats. One or more
of the following adjustments can be made to
produce a wetter spray:
a. Open fluid feed valve more.
b. Reduce size of pattern.
c. Decrease gun distance.
d. Slow down stroke.
e. Allow less flash time between coats.
f.
Case should be taken to prevent flooding
and mottling.
3. If
the repair is too dark, spray several coats that
are lighter and more metallic looking. Reverse
the above adjustments using one or more of the
following:
a. Close fluid valve slightly.
b. Increase the size
of the pattern.
c. Increase gun distance.
d. Speed up stroke.
e. Increase flash time between
coats.
f. Care should be
taken, as dry spray
increases orange peel.
4. When matching a difficult color that has a line
of definition, such as a panel or spot repair on an
edge, blend the fourth and fifth coats into the
adjacent panel.
5. Experienced painters generally have the ability
to tint colors for incorrect color hue. Tinting
guides are available from the various paint man-
ufacturers for those who have the base tinting
colors and the ability to tint colors to match.
REMEMBER
- The true color of metallics
will not come through until the finish has been com-
pounded and buffed.
Painting Primed Service Replacement
Urethane Panels
Follow Steps 1 thru 8 under "Coloring
Procedure.
"