1988 PONTIAC FIERO Service Repair Manual

1 Dl-18 R-4 AIR CONDITIONING COMPRESSOR OVERHAUL
Install or Connect
1. Check the compressor cylinder assembly and
interior of the compressor Shell to be sure they
are free of lint, dirt, etc.
2. Dip a new cylinder-to-shell O-ring in clean 525
viscosity refrigerant oil and install in the rear
O-ring groove of the cylinder. Be careful in
moving the O-ring across the cylinder surface to
prevent damaging the O-ring.
3. Dip the remaining cylinder-to-shell O-ring in the
525 oil and install it in the front O-ring groove of
the cylinder.
4. Also coat inner O-ring surface
of compressor
Shell with oil. Place the compressor Shell on the
cylinder and rotate the retaining strap to its
original location.
5. Attach the
Shell Installing Fixture
J-25008-A to
the Holding Fixture J-25008-A, using the
long-bolts and plate washers of the set. Align the
step projections of the Installing Fixture
J-25008-A, to contact the compressor Shell
evenly on both sides.
6. Push the compressor shell as close to the O-ring
as possible by hand and check for equal alignment
of the shell around the cylinder. Tighten the
Fixture screws finger tight.
1 -J-25008-A 2-J-25008-A 3-ALT. TIGHTEN
COMPRESSOR HOLDING SCREWS
SHELL FIXTURE APPROX.
INSTALLER
114 TURN 520049-1 Dl
Fig. 50 Installing Shell
7. Alternately tighten each bolt approximately 1/4
turn to push the compressor Shell over the
O-rings and back against the shell stop flange at
the rear of the compressor cylinder.
If one screw appears to require more force to turn
than the other, immediately turn the other screw
to bring the screw threading sequence in-step or
the shell will be cocked and made more difficult
to install. Normal installation does not require
much force on the wrench if the screws are kept
in-step while turning.
8. When the shell is seated against the stops, bend
the shell retaining strap down into place by
tapping gently with a hammer. Remove the Shell
Installing Fixture J-25008-A. 9.
Reinstall Clutch Rotor and Bearing Asm., Clutch
Coil and Pulley Rim as an assembly with Installer
5-262714, and the Clutch Plate and Nub
Assembly with Installer J-9480-B.
10.
"Evacuate and Charge the Refrigerant System"
according to the directions in Section
1B.
DISCHARGE VALVE PLATE AND RETAINER
Fig. 5 1,52
1 -VALVE PLATE
2-J 4245 PLIERS
I RETAINER RING I
Fig. 5 1 Replacing Valve Plate Retainer
1 -VALVE PLATE
Fig.
52 Replacing Discharge Valve Plate
Remove or Disconnect
1.
Discharge the refrigerant system according to the
directions in Section
1B.
2. Perform Steps 1 through 9 of SHELL AND
O-RINGS removal procedure.
3. Remove valve plate retainer ring, using Internal
Snap Ring Pliers
J-4245. Remove Compressor
Discharge Valve Plate for valve plate
replacement and/or piston inspection.
Repeat this operation for additional valve plates
and retainer rings. If all four valve plates and

R-4 818 CONDITIONING COMPRESSOR OVERHAUL 1D1-19
retainers are to be removed, remove two sets and
then rotate compressor and Holding Fixture
J-25008-A in vise for access to the remaining two
valve plates and retainers.
Install or Connect
1. Install Discharge Valve Plates and/or Retainers.
Reposition compressor and Holding Fixture in
vise as necessary for access.
Valve plates must
be tight
following retainer assembly.
2. Reinstall compressor Shell as described in
SHELL AND O-RINGS replacement
procedures.
3. Evacuate and charge the refrigerant system
according to the directions in Section
1B.
CYLINDER AND SHAFT ASSSEMBLY
Remove or Disconnect
Discharge the refrigerant system according to the
directions in Section
1B.
Remove the Clutch Plate and Hub assembly as
described in CLUTCH PLATE AND HUB
removal procedure.
Perform Steps
1 through 4 of CLUTCH ROTOR
AND BEARING removal procedure but do not
loosen or remove the pulley rim mounting screws.
Remove the Clutch Rotor and Bearing, Clutch
Coil and Pulley Rim as an assembly. Be careful
not to drop the Puller Guide J-25031, when
removing the assembly.
Remove the shaft seal as described in SHAFT
SEAL removal procedure.
Remove the front head as described in FRONT
HEAD REMOVAL procedure.
Remove the thrust and belleville washers as
described in THRUST AND BELLEVILLE
WASHERS removal procedures.
Remove the compressor shell as described in
SHELL removal procedure.
Remove the discharge valve plate and retainer as
described in DISCHARGE VALVE PLATE
AND RETAINER removal procedure.
Remove the high pressure relief valve as
described in
HIGH PRESSURE RELIEF
VALVE REMOVAL PROCEDURE.
L
Install or Connect
1. Replace above parts in opposite order.
2. Evacuate and charge the refrigerant system
according to the directions in Section
1B.
LEAK TESVING (EXTERNAL AND INTERNAL)
Bench-Check Procedure
1. Install Test Plate J-9625-A on Rear Head of
compressor.
2. Attach center hose of Manifold Gage Set on
Charging Station to a refrigerant drum standing
in an upright position and open valve on drum.
3. Connect Charging Station high and low pressure
lines to corresponding fittings on Test Plate J-9625-A, using
5-5420 Gage
Adapters if hoses
are not equipped with valve depressors.
Suction port (low-side) of compressor has
large internal opening. Discharge port
(hi-side) has smaller internal opening into
compressor.
Open low-pressure control, high-pressure control
and refrigerant control on Charging Station to
allow refrigerant vapor to flow into compressor.
Using a Leak Detector, check for leaks at
Pressure Relief Valve, compressor shell to
cylinder, compressor front head seal, and
compressor Shaft Seal. After checking, shut off
low pressure control and high pressure control on
Charging Station.
If an external leak is present, perform the
necessary corrective measures and recheck for
leaks to make certain the leak has been corrected.
Loosen the Manifold Gage hose connections to
the Gage Adapters J-5420 connected to the low
and high sides and allow the vapor pressure to
release from the compressor.
Disconnect both Gage Adapters
5-5420 from the
Test Plate J-9625-A.
Rotate the complete compressor assembly (not
the crankshaft or drive plate hub) slowly several
turns to distribute oil to all cylinder and piston
areas.
Install a shaft nut on the compressor crankshaft
if the drive plate and clutch assembly are not
installed.
Using a box-end wrench or socket and handle,
rotate the compressor crankshaft or clutch drive
plate on the crankshaft several turns to ensure
piston assembly to cylinder wall lubrication.
Connect the Charging Station high pressure line
or a high pressure gage and Gage Adapter J-5420
to the Test Plate J-9625-A high side connector.
Attach an Adapter
9-5420 to the suction or low
pressure port of the Test Plate
J-9625-19 to open
the Schrader-type valve.
Oil will drain out of the compressor suction port
adapter if the compressor is positioned with the
suction port downward.
Attach the compressor to the Holding Fixture
J-25008-A using metric mounting screws. Clamp
the compressor Holding Fixture in a vise so that
the compressor can be manually turned with a
wrench.
Using a wrench, rotate the compressor crankshaft
or drive plate hub ten complete revolutions at a
speed of approximately one-revolution per
second.
Turning the compressor at less than
one-revolution per second can result in a lower
pump-up pressure and disqualify a good pumping
compressor.
Observe the reading on HIGH pressure gage at
the completion of the tenth revolution of the
compressor. The pressure reading for a good
pumping compressor should be 344.75
kPa (50 p.
s.i.) or above. A pressure reading of less than 3 10.
275 kPa (45 p.s.i.) would indicate one or more

101.20 R-4 AIR CONDITIONING COMPRESSOR OVERHAUL
suction and/or discharge valves leaking, an
internal leak or an inoperative valve, and the
compressor should be disassembled and checked
for cause of leak. Repair as needed, reassemble
and repeat the pump-up test. Externally leak test.
When the pressure pump-up test is completed,
release the air pressure from the HIGH side and
remove the Gage Adapters J-5420 and Test Plate
J-9625-A. 18. On the R-4 compressor, tilt the compressor so
that the compressor suction and discharge ports
are down. Drain the oil from the compressor.
19. Allow the compressor to drain for
10 minutes,
then charge with the proper amount of oil. The
oil may be poured into the suction port.
If further assembly or processing is required, a
shipping plate or Test Plate J-9625-A should be
installed to keep out air, dirt and moisture until
the compressor is installed.

R-4 AIR CONDITIONING COMPRESSOR OVERHAUL 1 Dl-21
SNAP RING PLIERS b23 INTERNAL ) 18-J-25008-A COMPRESSOR HOLDING FIXTURE
SNAP
RING PLIERS @21 INTERNAL) 19-J-25031 ROTOR
AND BEARING PULLER WITH SNAP RING PLIERS 44424 INTERNAL)
GUIDE
DRIVER HANDLE 20-J-25287 CLUTCH COIL PULLER
COMPRESSOR PULLEY PULLER 21-J-26271.A ROTOR AND BEARING INSTALLER
ROTOR BEARING REMOVER (WITHOUT HANDLE)
9/16"
THIN WALL SOCKET
22-J-33019 BEARING STAKING TOOL
HUB AND DRIVE PLATE ASSEMBLY "23-J-33020 PULLEY PULLER
REMOVER 24-J-33027 CLUTCH HUB HOLDING TOQL
HUB AND DRIVE PLATE ASSEMBLY 25-J-34614 SHAFT SEAL PROTECTOR
INSTALLER 26-J-33011 SEAL SEAT O-RING INSTALLER
PULLEY BEARING AND PULLEY INSTALLER
27-J-29547 ELECTRONIC LEAK DETECTOR
O-RING REMOVER 28-J-5420 7116"-20 STRAIGHT ADAPTER
PRESSURE TEST CONNECTOR 28-J-25498 7116"-20 x 3/8-24 STRAIGHT ADAPTER
COMPRESSOR SUPPORT BLOCK 29-J-9459 7116"-20 90" ELBOW ADAPTER
SEAL REMOVER AND INSTALLER 29-J-25499 7/16-20 x 318"-24 90" ELBOW
PULLEY HUB ADAPTER SET (USED ADAPTER
WITH
J-8433) 30-J-25030 CLUTCH HUB HOLDING TOOL
BEARING INSTALLER (FRONT END) 31-J-33024 CLUTCH COIL INSTALLER ADAPTER
HEAD) "Indicates tools used only on the 6 pole clutch
Fig.
53 Special Tools, R-4 A/C Compressor Overhaul

BUMPERS 28-1
SECTION 2B
BUMPERS
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.
NOTICE: The anti-theft label on some major sheet metal, engines, and transmissions must be masked prior to
painting, rustproofing, undercoating, etc. The mask MUST be removed following the above operations. Failure to keep
the label clean and readable may result in liability for violation of Federal Vehicle Theft Prevention Standard, and subject
the vehicle owner to possible suspicion that the part was stolen.
CONTENTS
General Description ................................ 2B-1 On-Vehicle Service ..................................... 2B-4
........................................... ..................... Service Procedures .. ........... 2B- 1 Specifications 2B-5
GENERAL DESCRIPWIBN
The bumpers on all Pontiac automobiles are remover.
Install new tape (double-coated neoprene
designed so that the vehicle can withstand a collision foam type)
to the back side of the rub strip.
into a fixed barrier at
5 mph. After absorbing the
energy of a collision, the bumpers restore themselves After
rub strip is installed, roll along entire
to their original position. surface with a roller
in order to insure a good bond.
The front and rear bumper fascias are made of
urethane. Urethane will withstand minor impact and
return to its original shape. Some front bumper fascias
are integral with the front end panel.
Some models use both steel and aluminum
bumper reinforcements. Usage is based on
EPA weight
class requirements.
BUMPER FASCIA RUB STRIPS
Some front and rear fascia rub strips are made of
a shiny plastic material. If a rub strip of this type loses
its lustre, the original shine can be restored by using
GM Plastic Cleaner or its equivalent. Follow directions
on the label.
SERVICE PROCEDURES
RUB STRIPS
Remove and Replace
Some plastic rub strips have an adhesive tape
backing (similar to a body side molding) and some have
studs or retaining tabs. In order to properly remove the
adhesive tape and avoid paint damage to the fascia, use
either a release agent or a heat lamp to soften the bond
of the adhesive tape to the fascia. In some cases, it will
be necessary to replace the rub strip with a new rub
strip instead of reusing the old one.
If the old rub strip is salvagable, remove all tape
from the back side of the rub strip as previously
described. Wipe strip clean with a wax and adhesive
FRONT BUMPER FASCIA (FRONT END PANEL)
Removal
Place a jack stand under fascia assembly before
removing bolts to prevent it from dropping down when
fascia attaching bolts are removed. Fascia will pivot on
the opposite end when one end is disconnected. Do not
rotate energy absorber any more than necessary to
align mounting holes.
1. Remove fascia attaching bolts and fascia to
fender attaching screws on right and left side, and
remove fascia and spacers.
2. If energy absorber is to be replaced, remove the
bolts and nuts from the front of the unit and the
nut from the stud at the rear.
Installation
1. Install energy absorber if removed.
2. Support fascia during installation to prevent
rotation of energy absorbers.
3. Install spacers and bolts at fascia to energy
absorber brackets.
4. Install fascia to fender attaching screws.
5. Check for proper clearance.
6. If adjustment is required to align fascia, loosen
energy absorber mounting bolts and position as
required (holes are slotted). Adjustment side to
side can be made by loosening fascia bracket
bolts. Torque all bolts and nuts. (See
Specifications.)

2B-2 BUMPERS
REAR BUMPER FASCIA
Removal
Place a jack stand under fascia before removing
bolts to prevent it from dropping down when fascia
attaching bolts are removed. Fascia will pivot on the
opposite end when one end is disconnected. Do not
rotate energy absorber any more than necessary to
align mounting holes.
1. Remove fascia attaching bolts and fascia to
fender attaching screws on right and left side, and
remove fascia and spacers.
2. If energy absorber is to be replaced, remove the
bolts and nuts from the front of the unit and the
nut from the stud at the rear. The stud at the rear
of the absorber is attached to a bracket in the
frame. Remove the bolt holding this bracket in
the frame to remove the absorber.
Installation
1. Install energy absorber if removed.
2. Support fascia during installation to prevent
rotation of energy absorbers.
3. Install spacers and bolts at fascia to energy
absorber brackets.
4. Install fascia to fender attaching screws.
5. Check for proper clearance.
6. If adjustment is required to align the fascia, use
shims as necessary. Vertical and lateral
adjustment can be made at slots in fascia and
absorber brackets. Torque all bolts and nuts. (See
Specifications.)
FRONT BUMPER
Removal
1. Remove
front end fascia as shown in Section 2C.
2. Remove bumper barlenergy absorber assembly
from body.
3. If energy absorber must be replaced, drill out pop
rivets, and install new absorber with nuts, bolts,
and locking washers.
4. To install, reverse above procedure.
REAR BUMPER
Removal
1. Remove left hand rear quarter trim panel.
2. Remove right hand rear quataer trim panel.
3. Remove spare tire assembly.
4. Remove rear center trim panel.
5. Remove right tail light assembly.
6. Remove left tail light assembly.
7. Remove tail light center piece.
8. Remove bumper cover lower retainers.
9. Remove right-side bumper cover fasteners from
inside of compartment.
10. Remove left side bumper cover fasteners from
inside of compartment.
11. Remove bumper cover upper retainers.
12. Remove cover.
13. To dissasemble impact bar, proceed as follows:
a. Remove bolts attataching impact bar to
rear end panel.
b. Remove rivets retaining pad to impact
bar.
14. To install, reverse above procedure.
BUMPER ENERGY ABSORBING UNITS
The absorbing capability for both front and rear
bumper systems is achieved through two energy
absorbing devices in each bumper. These units convert
the energy of an impact into heat and restoration. The
energy absorbing device consists of two main
subassemblies: the piston tube assembly and the
cylinder tube assembly. The piston tube assembly is
filled with an inert gas under pressure and consists of
a bumper bracket, piston tube, orifice, seal, piston seal,
piston, and stop-ring. The cylinder tube assembly is
filled with a hydraulic fluid and consists of a frame
bracket, cylinder tube, mounting stud, and metering
pin.
Upon impact, as the energy absorber is collapsed,
the hydraulic fluid in the cylinder tube is forced into
the piston tube through the orifice. The metering pin
controls the rate at which this fluid passes from the
cylinder tube through the orifice and into the piston
tube. This controlled passage of fluid provides the
energy absorbing action.
The hydraulic fluid that is forced from the
cylinder tube into the piston tube displaces the floating
piston, compressing the gas behind the floating piston.
After impact, the pressure of the compressed gas
behind the floating piston forces the hydraulic fluid
back into the cylinder tube assembly, extending the
unit to its normal position.
Some front and rear bumpers (J and
F Models)
use a plastic honeycomb pad energy absorber (except
J wagon rear bumper). This energy absorber will
compress on impact, and both the energy absorber and
the urethane fascia will return to their original shape.
The energy absorber pad has no moving parts.
The J wagon rear bumper system uses a hydraulic
energy absorbing unit, more commonly known as a
"minisorber".
TESTING FRONT OR REAR ENERGY
ABSORBER OPERATION
The right and left energy absorbing devices are to
be diagnosed separately. The following checks are to be
made on each unit:
1. Leakage
Some oil wetting may be visible due to the grease
packed in the crimp recess. Therefore, a stain or trace
of oil on the piston tube near the crimp is normal.
However, if oil is dripping continuously from the crimp
or the stud end of the unit, a leak is indicated and the
unit should be replaced.

BUMPERS 28-3
Check the bumper bracket, piston tube, frame
bracket and cylinder tube for evidence of visible
distortion. Scuffing of the piston tube will occur when
the unit is stroked, and this is considered normal.
If there is obvious damage to the unit, it should
be replaced.
3. On-Bench Test
a. Position energy absorber lengthwise in arbor
press.
b. Using
a suitable measuring device, note original
position of unit, then use press to compress unit
at least
3/8".
c. Release pressure and determine whether unit has
returned to original position.
If not, discard unit.
4. Inspection After Collision
If the collision was so severe that the bumper did
not return to its original position, the energy
absorber(s) will require replacing.
a. Stand clear
of the bumper.
b. Provide
a positive restraint, such as a chain or
cable to hold the bumper in position.
c.
WEARING SAFETY GLASSES, drill a small
hole in the piston tube near the bumper bracket,
Fig.
2, to relieve gas pressure.
Fig. 2 Scrapping Energy Absorber
d. Remove the energy absorber(§) after gas pressure
has been relieved.
CAUTION: Failure to observe the
following procedures when handling
energy absorbing devices
nnay result
in personal injury.
1. Do not apply heat to unit.
2. Do not weld near unit.
3. Do not attempt to repair a damaged unit.
Always replace it with a new unit.
4. If a unit is bound-up as a result of a collision
such that it cannot extend, take precautions
to avoid spring-back when bending sheet
metal.
5. If
a unit is to be scrapped, relieve the gas
pressure prior to disposal of the unit. Make
an indentation with a center punch in the
small cylinder section of the energy
absorber, Fig.
1. Use a 1/8 inch drill to
penetrate the small cylinder wall.
Alternate Scrapping Procedure
The following alternate procedure for
deactivating the energy absorber may be used
ONLY
IF the absorber is in the extended position.
1. Mount energy absorber frame bracket in vise.
2. Using a 5/32" drift pin punch, drive sealing ball
inward.
BE SAFE. PROTECT YOUR EYES.
WEAR
APPROVED SAFETY GLASSES.