(4) Remove caliper assembly from adapter and
rotor by first rotating top of caliper assembly away
from adapter, and then lifting caliper assembly off
lower machined abutment on adapter (Fig. 71).
(5) Support caliper assembly firmly from rear strut
to prevent weight of caliper from damaging the flex-
ible brake hose (Fig. 72).
INSTALL
NOTE: Step 1 below is only required when install-
ing the disc brake caliper, after new brake shoes
have been installed.
(1) Completely retract caliper piston back into pis-
ton bore of caliper assembly.
(2) Lubricate both adapter abutments with a lib-
eral amount of MopartMultipurpose Lubricant, or
equivalent.(3) If removed, install the rear rotor on the hub
making sure it is squarely seated on the face of the
hub (Fig. 73).
CAUTION: Use care when installing caliper assem-
bly onto adapter so the guide pin bushings and
sleeves do not get damaged by the mounting
bosses on adapter.
Fig. 70 Caliper Assembly Guide Pin Bolts
Fig. 71 Removing Caliper Assembly From Adapter
Fig. 72 Storing Caliper
Fig. 73 Installing Rear Rotor
PLBRAKES 5 - 31
REMOVAL AND INSTALLATION (Continued)
from adapter, and then lifting caliper assembly off
lower machined abutment on adapter (Fig. 75).
(5) Support caliper assembly firmly from rear strut
to prevent weight of caliper from damaging the flex-
ible brake hose (Fig. 76).
(6) Remove rear rotor from hub/bearing assembly
(Fig. 77). Then inspect drum-in-hat parking brake
shoes and parking brake braking surface on rotor for
any signs of excessive wear or damage. Replace park-
ing brake shoes if required.
(7) Remove outboard brake pad from caliper by
prying brake pad retaining clip over raised area oncaliper. Then slide brake pad down and off the cali-
per (Fig. 78).
(8) Pull inboard brake pad away from caliper pis-
ton, until retaining clip is free from cavity in piston.
(Fig. 79).
CALIPER INSPECTION
Check caliper for piston seal leaks (brake fluid in
and around boot area and inboard lining) and for any
ruptures of the piston dust boot. If boot is damaged,
Fig. 75 Removing/Installing Caliper Assembly From
Adapter
Fig. 76 Storing Caliper
Fig. 77 Rear Brake Rotor
Fig. 78 Outboard Brake Shoe
PLBRAKES 5 - 33
REMOVAL AND INSTALLATION (Continued)
This is accomplished by a sophisticated system of
electrical and hydraulic components. As a result,
there are a few performance characteristics that may
at first seem different but should be considered nor-
mal. These characteristics are discussed below.
NORMAL BRAKING SYSTEM FUNCTION
Under normal braking conditions, the ABS System
functions the same as a standard brake system with
a diagonally split master cylinder and conventional
vacuum assist.
ABS SYSTEM OPERATION
If a wheel locking tendency is detected during a
brake application, the brake system will enter the
ABS mode. During ABS braking, hydraulic pressure
in the four wheel circuits is modulated to prevent
any wheel from locking. Each wheel circuit is
designed with a set of electric solenoids to allow mod-
ulation, although for vehicle stability, both rear
wheel solenoids receive the same electrical signal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into four control channels.
During antilock operation of the vehicle's brake sys-
tem the front wheels are controlled independently
and are on two separate control channels and the
rear wheels of the vehicle are controlled together.
The system can build and release pressure at each
wheel, depending on signals generated by the wheel
speed sensors (WSS) at each wheel and received at
the Controller Antilock Brake (CAB).
ABS operation is available at all vehicle speeds
above 3 to 5 mph. Wheel lockup may be perceived at
the very end of an ABS stop and is considered nor-
mal.
VEHICLE HANDLING PERFORMANCE DURING
ABS BRAKING
It is important to remember that an antilock brake
system does not shorten a vehicle's stopping distance
under all driving conditions, but does provide
improved control of the vehicle while stopping. Vehi-
cle stopping distance is still dependent on vehicle
speed, weight, tires, road surfaces and other factors.
Though ABS provides the driver with some steer-
ing control during hard braking, there are conditions
however, where the system does not provide any ben-
efit. In particular, hydroplaning is still possible when
the tires ride on a film of water. This results in the
vehicles tires leaving the road surface rendering the
vehicle virtually uncontrollable. In addition, extreme
steering maneuvers at high speed or high speed cor-
nering beyond the limits of tire adhesion to the road
surface may cause vehicle skidding, independent of
vehicle braking. For this reason, the ABS system is
termed Antilock instead of Anti-Skid.
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping and/or groaning noises heard by the
driver. This is normal due to pressurized fluid being
transferred between the master cylinder and the
brakes. If ABS operation occurs during hard braking,
some pulsation may be felt in the vehicle body due to
fore and aft movement of the suspension as brake
pressures are modulated.
At the end of an ABS stop, ABS will be turned off
when the vehicle is slowed to a speed of 3±4 mph.
There may be a slight brake pedal drop anytime that
the ABS is deactivated, such as at the end of the stop
when the vehicle speed is less then 3 mph or during
an ABS stop where ABS is no longer required. These
conditions will exist when a vehicle is being stopped
on a road surface with patches of ice, loose gravel or
sand on it. Also stopping a vehicle on a bumpy road
surface will activate ABS because of the wheel hop
caused by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lock-up, some wheel slip is desired in order to
achieve optimum braking performance. Wheel slip is
defined as follows, 0 percent slip means the wheel is
rolling freely and 100 percent slip means the wheel is
fully locked. During brake pressure modulation,
wheel slip is allowed to reach up to 25 to30%. This
means that the wheel rolling velocity is 25 to 30%
less than that of a free rolling wheel at a given vehi-
cle speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lock-up.
Complete wheel lock up normally leaves black tire
marks on dry pavement. The ABS System will not
leave dark black tire marks since the wheel never
reaches a fully locked condition. Tire marks may
however be noticeable as light patched marks.
START UP CYCLE
When the ignition is turned on, a popping sound
and a slight brake pedal movement may be noticed.
Additionally, when the vehicle is first driven off a
humming may be heard and/or felt by the driver at
approximately 20 to 40 kph (12 to 25 mph). The ABS
warning lamp will also be on for up to 5 seconds
after the ignition is turned on. All of these conditions
are a normal function of ABS as the system is per-
forming a diagnosis check.
5 - 70 BRAKESPL
DESCRIPTION AND OPERATION (Continued)
CRANKSHAFT POSITION SENSOR
The PCM determines what cylinder to fire from the
crankshaft position sensor input and the camshaft
position sensor input. The second crankshaft counter-
weight has machined into it two sets of four timing
reference notches including a 60 degree signature
notch (Fig. 6). From the crankshaft position sensor
input the PCM determines engine speed and crank-
shaft angle (position).
The notches generate pulses from high to low in
the crankshaft position sensor output voltage. When
a metal portion of the counterweight aligns with the
crankshaft position sensor, the sensor output voltage
goes low (less than 0.5 volts). When a notch aligns
with the sensor, voltage goes high (5.0 volts). As a
group of notches pass under the sensor, the output
voltage switches from low (metal) to high (notch)
then back to low.
If available, an oscilloscope can display the square
wave patterns of each voltage pulse. From the fre-
quency of the output voltage pulses, the PCM calcu-
lates engine speed. The width of the pulses represent
the amount of time the output voltage stays high
before switching back to low. The period of time the
sensor output voltage stays high before switching
back to low is referred to as pulse-width. The faster
the engine is operating, the smaller the pulse-width
on the oscilloscope.
By counting the pulses and referencing the pulse
from the 60 degree signature notch, the PCM calcu-
lates crankshaft angle (position). In each group of
timing reference notches, the first notch represents
69 degrees before top dead center (BTDC). The sec-
ond notch represents 49 degrees BTDC. The third
notch represents 29 degrees. The last notch in eachset represents 9 degrees before top dead center
BTDC.
The timing reference notches are machined at 20É
increments. From the voltage pulse-width the PCM
tells the difference between the timing reference
notches and the 60 degree signature notch. The 60
degree signature notch produces a longer pulse-width
than the smaller timing reference notches. If the
camshaft position sensor input switches from high to
low when the 60 degree signature notch passes under
the crankshaft position sensor, the PCM knows cylin-
der number one is the next cylinder at TDC.
The crankshaft position sensor mounts to the
engine block behind the generator, just above the oil
filter (Fig. 7).
CAMSHAFT POSITION SENSOR
The PCM determines fuel injection synchronization
and cylinder identification from inputs provided by
Fig. 6 Timing Reference Notches
Fig. 7 Crankshaft Position Sensor
8D - 4 IGNITION SYSTEMPL
DESCRIPTION AND OPERATION (Continued)
HEADLAMP ALIGNMENT
INDEX
page page
GENERAL INFORMATION
HEADLAMP ALIGNMENT................... 4
SERVICE PROCEDURES
HEADLAMP ALIGNMENT PREPARATION....... 4ADJUSTMENTS
FOG LAMP ALIGNMENT................... 4
HEADLAMP ADJUSTMENT USING ALIGNMENT
SCREEN.............................. 4
GENERAL INFORMATION
HEADLAMP ALIGNMENT
Headlamps can be aligned using the screen method
provided in this section.
SERVICE PROCEDURES
HEADLAMP ALIGNMENT PREPARATION
(1) Verify headlamp dimmer switch and high beam
indicator operation.
(2) Inspect and correct damaged or defective com-
ponents that could interfere with proper headlamp
alignment.
(3) Verify proper tire inflation.
(4) Clean headlamp lenses.
(5) Verify that luggage area is not heavily loaded.
(6) Fuel tank should be FULL. Add 2.94 kg (6.5
lbs.) of weight over the fuel tank for each estimated
gallon of missing fuel.
ADJUSTMENTS
HEADLAMP ADJUSTMENT USING ALIGNMENT
SCREEN
ALIGNMENT SCREEN PREPARATION
(1) Position vehicle on a level surface perpendicu-
lar to a flat wall 7.62 meters (25 ft.) away from front
of headlamp lens (Fig. 1).
(2) If necessary, tape a line on the floor 7.62
meters (25 ft.) away from and parallel to the wall.
(3) From the floor up 1.27 meters (5 ft.), tape a
line on the wall at the center line of the vehicle.
Sight along the center line of the vehicle (from rear
of vehicle forward) to verify accuracy of the line
placement.
(4) Rock vehicle side-to-side three times to allow
suspension to stabilize.(5) Jounce front suspension three times by pushing
downward on front bumper and releasing.
(6) Measure the distance from the center of head-
lamp lens to the floor. Transfer measurement to the
alignment screen (with tape). Use this line for
up/down adjustment reference.
(7) Measure distance from the center line of the
vehicle to the center of each headlamp being aligned.
Transfer measurements to screen (with tape) to each
side of vehicle center line. Use these lines for left/
right adjustment reference.
HEADLAMP ADJUSTMENT
A properly aimed low beam headlamp will project
the center of the low beam hot spot on the alignment
screen from 178 mm (7 in.) below the headlamp cen-
ter line. The side- to-side left edge of low beam hot
spot should be 127 mm (5 in.) to the right of head-
lamp center line (Fig. 1). The high beams on a vehi-
cle with aero headlamps cannot be aligned. The high
beam pattern should be correct when the low beams
are aligned properly.
To adjust headlamp alignment, rotate alignment
screws to achieve the specified low beam hot spot
pattern.
FOG LAMP ALIGNMENT
Prepare an alignment screen. Refer to Alignment
Screen Preparation paragraph in this section. Disen-
gage the wire connectors from the back of the head-
lamp bulbs to disable the headlamps. This will allow
a more accurate projection reading of the fog lamps.
Turn on the headlamp switch and actuate the fog
lamp switch. A properly aligned fog lamp will project
a pattern on the alignment screen 100 mm (4 in.)
below the fog lamp centerline and straight ahead
(Fig. 2).
8L - 4 LAMPSPL
HONING CYLINDER BORES
(1) Used carefully, the cylinder bore resizing hone
C-823 equipped with 220 grit stones, is the best tool
for this job. In addition to deglazing, it will reduce
taper and out-of-round as well as removing light
scuffing, scoring or scratches. Usually a few strokes
will clean up a bore and maintain the required lim-
its.
(2) Deglazing of the cylinder walls may be done
using a cylinder surfacing hone, Tool C-3501,
equipped with 280 grit stones, if the cylinder bore is
straight and round. 20-60 strokes depending on the
bore condition, will be sufficient to provide a satisfac-
tory surface. Inspect cylinder walls after each 20
strokes, using a light honing oil.Do not use engine
or transmission oil, mineral spirits or kerosene.
(3) Honing should be done by moving the hone up
and down fast enough to get a cross-hatch pattern.
When hone marksintersectat 50-60 degrees, the
cross hatch angle is most satisfactory for proper seat-
ing of rings (Fig. 2).
(4) A controlled hone motor speed between
200-300 RPM is necessary to obtain the proper cross-
hatch angle. The number of up and down strokes per
minute can be regulated to get the desired 50-60
degree angle. Faster up and down strokes increase
the cross-hatch angle.
(5) After honing, it is necessary that the block be
cleaned again to remove all traces of abrasive.
CAUTION: Ensure all abrasives are removed from
engine parts after honing. It is recommended that a
solution of soap and hot water be used with a
brush and the parts then thoroughly dried. The bore
can be considered clean when it can be wiped
clean with a white cloth and cloth remains clean.
Oil the bores after cleaning to prevent rusting.
MEASURING MAIN BEARING AND CONNECTING
ROD BEARING CLEARANCES
PLASTIGAGE METHOD
Engine crankshaft bearing clearances can be deter-
mined by use of Plastigage or equivalent. The follow-
ing is the recommended procedure for the use of
Plastigage:
NOTE: The total clearance of the main bearings
can only be determined by removing the weight of
the crankshaft. This can be accomplished by either
of two methods:
PREFERRED METHOD
Shimming the bearings adjacent to the bearing to
be checked in order to remove the clearance between
upper bearing shell and the crankshaft. This can be
accomplished by placing a minimum of 0.254 mm
(0.010 in.) shim (e. g. cardboard, matchbook cover,
etc.) between the bearing shell and the bearing cap
on the adjacent bearings and tightening bolts to
14-20 N´m (10-15 ft. lbs.). The number of main bear-
ing will vary from engine to engine.
ENGINE WITH 5 MAIN BEARINGS
²When checking #1 main bearing shim #2 main
bearing.
²When checking #2 main bearing shim #1 & 3
main bearing.
²When checking #3 main bearing shim #2 & 4
main bearing.
²When checking #4 main bearing shim #3 & 5
main bearing.
²When checking #5 main bearing shim #4 main
bearing.
ENGINE WITH 4 MAIN BEARING
²When checking #1 main bearing shim # 2 main
bearing.
²When checking #2 main bearing shim #1 & #3
main bearing.
Fig. 2 Cylinder Bore Cross-Hatch Pattern
Fig. 3 Plastigage Placed in Lower Shell
PLENGINE 9 - 3
GENERAL INFORMATION (Continued)
²When checking #3 main bearing shim #2 & #4
main bearing.
²When checking #4 main bearing shim #3 main
bearing.
NOTE: REMOVE ALL SHIMS BEFORE REASSEM-
BLING ENGINE
ALTERNATIVE METHOD
The weight of the crankshaft can be supported by a
jack under the counterweight adjacent to the bearing
being checked.
PLASTIGAGE PROCEDURE
(1) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(2) Place a piece of Plastigage across the entire
width of the bearing shell in the cap approximately
6.35 mm (1/4 in.) off center and away from the oil
holes (Fig. 3). (In addition, suspected areas can be
checked by placing the Plastigage in the suspected
area). Torque the bearing cap bolts of the bearing
being checked to the proper specifications.
(3) Remove the bearing cap and compare the
width of the flattened Plastigage (Fig. 4) with the
metric scale provided on the package. Locate the
band closest to the same width. This band shows the
amount of clearance in thousandths of a millimeter.
Differences in readings between the ends indicate the
amount of taper present. Record all readings taken.
Refer to Engine Specifications.Plastigage gener-
ally is accompanied by two scales. One scale is
in inches, the other is a metric scale.
NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
CONNECTING ROD BEARING CLEARANCE
Engine connecting rod bearing clearances can be
determined by use of Plastigage or equivalent. The
following is the recommended procedure for the use
of Plastigage:(1) Rotate the crankshaft until the connecting rod
to be checked is at the bottom of its stroke.
(2) Remove oil film from surface to be checked.
Plastigage is soluble in oil.
(3) Place a piece of Plastigage across the entire
width of the bearing shell in the bearing cap approx-
imately 6.35 mm (1/4 in.) off center and away from
the oil hole (Fig. 3). In addition, suspect areas can be
checked by placing plastigage in the suspect area.
(4) Assemble the rod cap with Plastigage in place.
Tighten the rod cap to the specified torque.Do not
rotate the crankshaft while assembling the cap
or the Plastigage may be smeared, giving inac-
curate results.
(5) Remove the bearing cap and compare the
width of the flattened Plastigage (Fig. 4) with the
scale provided on the package. Locate the band clos-
est to the same width. This band indicates the
amount of oil clearance. Differences in readings
between the ends indicate the amount of taper
present. Record all readings taken. Refer to Engine
Specifications.Plastigage generally is accompa-
nied by two scales. One scale is in inches, the
other is a metric scale. If the bearing clearance
exceeds 0.076 mm (0.003 in.) replace bearing.
NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
REPAIR OF DAMAGED OR WORN THREADS
Damaged or worn threads (including aluminum
head spark plug threads) can be repaired. Essen-
tially, this repair consists of drilling out worn or
damaged threads, tapping the hole with a special
Heli-Coil Tap, (or equivalent) and installing an insert
into the tapped hole. This brings the hole back to its
original thread size.
CAUTION: Be sure that the tapped holes maintain
the original centerline.
Heli-Coil tools and inserts are readily available
from automotive parts jobbers.
HYDROSTATIC LOCKED ENGINE
When an engine is suspected to be hydrostatically
locked, regardless of what caused the problem, these
steps should be used.
CAUTION: Do Not Use Starter Motor To Rotate
Engine, severe damage may occur.
(1) Inspect air cleaner, induction system and
intake manifold to insure system is dry and clear of
foreign material.
Fig. 4 Clearance Measurement
9 - 4 ENGINEPL
GENERAL INFORMATION (Continued)
MAIN/ROD BEARINGS
A diagonal hole in each bulkhead feeds oil to each
main bearing. Drilled passages within the crankshaft
route oil from main bearing journals to connecting
rod journals.
CAMSHAFT/HYDRAULIC LASH ADJUSTERS
A vertical hole at the number five bulkhead routes
pressurized oil through a restrictor up into the cylin-
der head. The rocker shafts route oil to the rocker
arms/hydraulic lash adjuster assemblies.
SPLASH LUBRICATION
Oil returning to the pan from pressurized compo-
nents supplies lubrication to the valve stems. Cylin-
der bores and wrist pins are splash lubricated from
directed slots on the connecting rod thrust collars.
ENGINE COMPONENTS
CYLINDER BLOCK AND BEDPLATE ASSEM-
B LY:A partial open deck is used for cooling and
weight reduction with water pump molded into the
block. Nominal wall thickness is 4 mm. The bedplate
incorporates main bearing caps. Rear seal retainer is
integral with the block.
CRANKSHAFT:A nodular cast iron crankshaft is
used. The engine has 5 main bearings, with number
3 flanged to control thrust. The 52 mm diameter
main and 48 mm diameter crank pin journals (all)
have undercut fillet radiuses that are deep rolled for
added strength. To optimize bearing loading 8 coun-
terweights are used. Hydrodynamic seals provide end
sealing, where the crankshaft exits the block.
Anaerobic gasket material is used for parting line
sealing. A sintered iron timing belt sprocket is
mounted on the crankshaft nose. This sprocket trans-
mits crankshaft movement, via timing belt to the
camshaft sprocket providing timed valve actuation.
PISTONS:The SOHC EngineDOES NOThave
provision for a free wheeling valve train. Non free
wheeling valve train means, in the event of a broken
timing belt Pistons will contact the Valves. All
engines use pressed-in piston pins to attach forged
powdered metal connecting rods. The connecting rods
are a cracked cap design and are not repairable. Hex
head cap screw are used to provide alignment and
durability in the assembly. Pistons And Connecting
rods are serviced as an assembly.
PISTON RINGS:The piston rings include a
molybdenum faced top ring for reliable compression
sealing and a taper faced intermediate ring for addi-
tional cylinder pressure control. Oil Control Ring
Package consist of 2 steel rails and a expander
spacer.
CYLINDER HEADÐSOHC:It features a Single
Over Head Camshaft, four-valves per cylinder cross
flow design. The valves are arranged in two inlinebanks, with the two intake per cylinder facing
toward the radiator. The exhaust valves facing
toward the dash panel. Rocker arm shafts mount
directly to the cylinder head. It incorporates powder
metal valve guides and seats. The hollow rocker arm
shafts supplies oil to the hydraulic lash adjusters,
camshaft and valve mechanisms.
CAMSHAFTÐSOHC:The nodular iron camshaft
has five bearing journals and 3 cam lobes per cylin-
der. Provision for cam position sensor on the cam at
the rear of cylinder head which also acts as thrust
plate. A hydrodynamic oil seal is used for oil control
at the front of the camshaft.
VALVESÐSOHC:Four valves per cylinder are
actuated by roller rocker arms/hydraulic lash adjust-
ers assemblies which pivot on rocker arm shafts. All
valves have 6 mm diameter chrome plated valve
stems. The valve train has 33 mm (1.299 inch) diam-
eter intake valves and 28 mm (1.10 inch) diameter
exhaust valves. Viton rubber valve stem seals are
integral with spring seats. Valve springs, spring
retainers, and locks are conventional design.
INTAKE MANIFOLD:The intake manifold is a
molded plastic composition, attached to the cylinder
head with ten fasteners. This long branch design
enhances low and mid-range torque.
EXHAUST MANIFOLD:The exhaust manifold is
made of nodular cast iron for strength and high tem-
peratures. Exhaust gasses exit through a machined,
articulated joint connection to the exhaust pipe.
DIAGNOSIS AND TESTING
CHECKING ENGINE OIL PRESSURE
(1) Remove oil pressure switch and install gauge
assembly C-3292 with adaptor.
(2) Run engine until thermostat opens.
CAUTION: If oil pressure is 0 at idle, Do Not per-
form the 3000 RPM test in the next step.
(3) Oil Pressure:Curb Idle25 kPa (4 psi) mini-
mum3000 RPM170-550 kPa (25-80 psi).
(4) If oil pressure is 0 at idle. Shut off engine,
check for pressure relief valve stuck open, a clogged
oil pick-up screen or a damaged oil pick-up tube
O-ring.
SERVICE PROCEDURES
CYLINDER BORE AND PISTON SIZING
The cylinder walls should be checked for out-of-
round and taper with Tool C-119 (Fig. 3). The cylin-
der bore out-of-round is 0.050 mm (.002 inch)
maximum and cylinder bore taper is 0.051 mm (0.002
9 - 14 2.0L SOHC ENGINEPL
DESCRIPTION AND OPERATION (Continued)