
tem enters the ABS mode. During ABS braking,
hydraulic pressure in the four wheel circuits is mod-
ulated to prevent any wheel from locking. Each
wheel circuit is designed with a set of electric sole-
noids to allow modulation, although for vehicle sta-
bility, both rear wheel solenoids receive the same
electrical signal. Wheel lockup may be perceived at
the very end of an ABS stop and is considered nor-
mal.
During an ABS stop, the brakes hydraulic system
is still diagonally split. However, the brake system
pressure is further split into three 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).
NOISE AND BRAKE PEDAL FEEL
During ABS braking, some brake pedal movement
may be felt. In addition, ABS braking will create
ticking, popping, or groaning noises heard by the
driver. This is normal and is 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 is 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 than 3 mph or during
an ABS stop where ABS is no longer required. These
conditions 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 sur-
face activates ABS because of the wheel hop caused
by the bumps.
TIRE NOISE AND MARKS
Although the ABS system prevents complete wheel
lockup, 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±30 percent. This means
that the wheel rolling velocity is 25±30 percent less
than that of a free rolling wheel at a given vehicle
speed. This slip may result in some tire chirping,
depending on the road surface. This sound should not
be interpreted as total wheel lockup.Complete wheel lockup normally leaves black tire
marks on dry pavement. The ABS will not leave dark
black tire marks since the wheel never reaches a
fully locked condition. However, tire marks may 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.
The ABS warning lamp will also be on for up to 5
seconds after the ignition is turned on. When the
vehicle is first driven off, a humming may be heard
or felt by the driver at approximately 20±40 kph
(12±25 mph). All of these conditions are a normal
function of ABS as the system is performing a diag-
nosis check.
PREMATURE ABS CYCLING
Symptoms of premature ABS cycling include: click-
ing sounds from the solenoid valves; pump/motor
running; and pulsations in the brake pedal. Prema-
ture ABS cycling can occur at any braking rate of the
vehicle and on any type of road surface. Neither the
red BRAKE warning lamp, nor the amber ABS warn-
ing lamp, illuminate and no fault codes are stored in
the CAB.
Premature ABS cycling is a condition that needs to
be correctly assessed when diagnosing problems with
the antilock brake system. It may be necessary to use
a DRB scan tool to detect and verify premature ABS
cycling.
Check the following common causes when diagnos-
ing premature ABS cycling: damaged tone wheels;
incorrect tone wheels; damaged steering knuckle
wheel speed sensor mounting bosses; loose wheel
speed sensor mounting bolts; excessive tone wheel
runout; or an excessively large tone wheel-to-wheel
speed sensor air gap. Give special attention to these
components when diagnosing a vehicle exhibiting
premature ABS cycling.
After diagnosing the defective component, repair or
replace it as required. When the component repair or
replacement is completed, test drive the vehicle to
verify that premature ABS cycling has been cor-
rected.
OPERATION - ELECTRONIC BRAKE
DISTRIBUTION
Upon entry into EBD the inlet valve for the rear
brake circuit is switched on so that the fluid supply
from the master cylinder is shut off. In order to
decrease the rear brake pressure, the outlet valve for
the rear brake circuit is pulsed. This allows fluid to
enter the low pressure accumulator (LPA) in the
hydraulic control unit (HCU) resulting in a drop in
fluid pressure to the rear brakes. In order to increase
5 - 68 BRAKES - ABSRS
BRAKES - ABS (Continued)

the rear brake pressure, the outlet valve is switched
off and the inlet valve is pulsed. This increases the
pressure to the rear brakes. This back-and-forth pro-
cess will continue until the required slip difference is
obtained. At the end of EBD braking (brakes
released) the fluid in the LPA drains back to the
master cylinder by switching on the outlet valve and
draining through the inlet valve check valve. At the
same time the inlet valve is switched on in case of
another brake application.
The EBD will remain functional during many ABS
fault modes. If both the red BRAKE, and amber ABS
warning indicators are illuminated, the EBD may not
be functioning.
OPERATION - TRACTION CONTROL SYSTEM
The traction control module monitors wheel speed.
During acceleration, if the module detects front
(drive) wheel slip and the brakes are not applied, the
module enters traction control mode. Traction control
operation proceeds in the following order:
(1) Close the normally open isolation valves.
(2) Start the pump/motor and supply volume and
pressure to the front (drive) hydraulic circuit. (The
pump/motor runs continuously during traction con-
trol operation.)
(3) Open and close the build and decay valves to
maintain minimum wheel slip and maximum trac-
tion.
The cycling of the build and decay valves during
traction control is similar to that during antilock
braking, except the valves work to control wheel spin
by applying the brakes, whereas the ABS function is
to control wheel skid by releasing the brakes.
If the brakes are applied at anytime during a trac-
tion control cycle, the brake lamp switch triggers the
controller to switch off traction control.
HYDRAULIC SHUTTLE VALVES
Two pressure relief hydraulic shuttle valves allow
pressure and volume to return to the master cylinder
reservoir when not consumed by the build and decay
valves. These valves are necessary because the
pump/motor supplies more volume than the system
requires.
TRACTION CONTROL LAMP
The traction control system is enabled at each igni-
tion cycle. It may be turned off by depressing the
Traction Control Off switch button when the ignition
is in the ON position. The traction control function
lamp (TRAC OFF) illuminates immediately upon
depressing the button.
The traction control function lamp illuminates dur-
ing a traction control cycle, displaying TRAC.If the CAB calculates that the brake temperatures
are high, the traction control system becomes inoper-
ative until a time-out period has elapsed. During this
ªthermo-protection mode,º the traction control func-
tion lamp illuminates TRAC OFF; note that no trou-
ble code is registered.
CAUTION
The ABS uses an electronic control module, the
CAB. This module is designed to withstand normal
current draws associated with vehicle operation.
Care must be taken to avoid overloading the CAB
circuits.
CAUTION: In testing for open or short circuits, do
not ground or apply voltage to any of the circuits
unless instructed to do so for a diagnostic proce-
dure.
CAUTION: These circuits should only be tested
using a high impedance multi-meter or the DRBIIIT
scan tool as described in this section. Power
should never be removed or applied to any control
module with the ignition in the ON position. Before
removing or connecting battery cables, fuses, or
connectors, always turn the ignition to the OFF
position.
CAUTION: The CAB 24-way connector should never
be connected or disconnected with the ignition
switch in the ON position.
CAUTION: Use only factory wiring harnesses. Do
not cut or splice wiring to the brake circuits. The
addition of aftermarket electrical equipment (car
phone, radar detector, citizen band radio, trailer
lighting, trailer brakes, etc.) on a vehicle equipped
with antilock brakes may affect the function of the
antilock brake system.
CAUTION: When performing any service procedure
on a vehicle equipped with ABS, do not apply a
12-volt power source to the ground circuit of the
pump motor in the HCU. Doing this will damage the
pump motor and will require replacement of the
entire HCU.
CAUTION: An attempt to remove or disconnect cer-
tain system components may result in improper
system operation. Only those components with
approved removal and installation procedures in
this manual should be serviced.
RSBRAKES - ABS5-69
BRAKES - ABS (Continued)

Schedule Condition Expected Operation
HotOil temperature at start-up above
80É F± Normal operation (upshift,
kickdowns, and coastdowns)
± Full EMCC, no PEMCC except to
engage FEMCC (except at closed
throttle at speeds above 70-83 mph)
OverheatOil temperature above 240É F or
engine coolant temperature above
244É F± Delayed 2-3 upshift (25-32 mph)
± Delayed 3-4 upshift (41-48 mph)
± 3rd gear FEMCC from 30-48 mph
± 3rd gear PEMCC from 27-31 mph
Super OverheatOil temperature above 260É F ± All9Overheat9shift schedule
features apply
± 2nd gear PEMCC above 22 mph
± Above 22 mph the torque
converter will not unlock unless the
throttle is closed or if a wide open
throttle 2nd PEMCC to 1 kickdown
is made
STANDARD PROCEDURE - PINION FACTOR
SETTING
NOTE: This procedure must be performed if the
Transmission Control Module (TCM) has been
replaced with a NEW or replacement unit. Failure to
perform this procedure will result in an inoperative
or improperly calibrated speedometer.
The vehicle speed readings for the speedometer are
taken from the output speed sensor. The TCM must
be calibrated to the different combinations of equip-
ment (final drive and tires) available. Pinion Factor
allows the technician to set the Transmission Control
Module initial setting so that the speedometer read-
ings will be correct. To properly read and/or reset the
Pinion Factor, it is necessary to use a DRB scan tool.
(1) Plug the DRB scan tool into the diagnostic con-
nector located under the instrument panel.
(2) Select the Transmission menu.
(3) Select the Miscellaneous menu.
(4) Select Pinion Factor. Then follow the instruc-
tions on the DRB scan tool screen.
STANDARD PROCEDURE - QUICK LEARN
PROCEDURE
The quick learn procedure requires the use of the
DRB scan tool. This program allows the electronic
transaxle system to recalibrate itself. This will pro-
vide the best possible transaxle operation.NOTE: The quick learn procedure should be per-
formed if any of the following procedures are per-
formed:
²Transaxle Assembly Replacement
²Transmission Control Module Replacement
²Solenoid/Pressure Switch Assembly Replacement
²Clutch Plate and/or Seal Replacement
²Valve Body Replacement or Recondition
To perform the Quick Learn Procedure, the follow-
ing conditions must be met:
²The brakes must be applied
²The engine speed must be above 500 rpm
²The throttle angle (TPS) must be less than 3
degrees
²The shift lever position must stay until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the DRB
indicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
(1) Plug the DRB scan tool into the diagnostic con-
nector. The connector is located under the instrument
panel.
(2) Go to the Transmission screen.
(3) Go to the Miscellaneous screen.
(4) Select Quick Learn Procedure. Follow the
instructions of the DRB to perform the Quick Learn
Procedure.
RSELECTRONIC CONTROL MODULES8E-27
TRANSMISSION CONTROL MODULE (Continued)

the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
should not be disassembled to determine the
cause of low compression unless some malfunc-
tion is present.
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
²Gradually apply air pressure from 1 psi to 2.5
psi maximum while applying soapy water at the sus-
pected source. Adjust the regulator to the suitable
test pressure that provides the best bubbles which
will pinpoint the leak source. If the oil leak is
detected and identified, repair per service manual
procedures.
²If the leakage occurs at the crankshaft rear oil
seal area, refer to the section, Inspection for Rear
Seal Area Leak.
(6) If no leaks are detected, turn off the air supply.
Remove the air hose, all plugs, and caps. Install the
PCV valve and fresh air hose (make-up air). Proceed
to next step.(7) Clean the oil off the suspect oil leak area using
a suitable solvent. Drive the vehicle at various
speeds approximately 24 km (15 miles). Inspect the
engine for signs of an oil leak by using a black light.
NOTE: If oil leakage is observed at the dipstick tube
to block location; remove the tube, clean and reseal
using MoparTStud & Bearing Mount (press fit tube
applications only), and for O-ring style tubes,
remove tube and replace the O-ring seal.
INSPECTION FOR REAR SEAL AREA LEAKS
Since it is sometimes difficult to determine the
source of an oil leak in the rear seal area of the
engine, a more involved inspection is necessary. The
following steps should be followed to help pinpoint
the source of the leak.
If the leakage occurs at the crankshaft rear oil seal
area:
(1) Disconnect the battery.
(2) Raise the vehicle.
(3) Remove torque converter or clutch housing
cover and inspect rear of block for evidence of oil.
Use a black light to check for the oil leak. If a leak is
present in this area, remove transmission for further
inspection.
(a) Circular spray pattern generally indicates
seal leakage or crankshaft damage.
(b) Where leakage tends to run straight down,
possible causes are a porous block, oil gallery cup
plug, bedplate to cylinder block mating surfaces
and seal bore. See proper repair procedures for
these items.
(4) If no leaks are detected, pressurize the crank-
case as previously described.
CAUTION: Do not exceed 20.6 kPa (3 psi).
(5) If the leak is not detected, very slowly turn the
crankshaft and watch for leakage. If a leak is
detected between the crankshaft and seal while
slowly turning the crankshaft, it is possible the
crankshaft seal surface is damaged. The seal area on
the crankshaft could have minor nicks or scratches
that can be polished out with emery cloth.
CAUTION: Use extreme caution when crankshaft
polishing is necessary to remove minor nicks and
scratches. The crankshaft seal flange is especially
machined to complement the function of the rear oil
seal.
(6) For bubbles that remain steady with shaft
rotation, no further inspection can be done until dis-
assembled.
9 - 4 ENGINE 2.4LRS
ENGINE 2.4L (Continued)

MopartGasket Sealant in an aerosol can should be
applied using a thin, even coat sprayed completely
over both surfaces to be joined, and both sides of a
gasket. Then proceed with assembly. Material in a
can w/applicator can be brushed on evenly over the
sealing surfaces. Material in an aerosol can should be
used on engines with multi-layer steel gaskets.
STANDARD PROCEDURES - ENGINE GASKET
SURFACE PREPARATION
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
Neveruse the following to clean gasket surfaces:
²Metal scraper
²Abrasive pad or paper to clean cylinder block
and head
²High speed power tool with an abrasive pad or a
wire brush (Fig. 3)
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
Only use the following for cleaning gasket surfaces:
²Solvent or a commercially available gasket
remover
²Plastic or wood scraper (Fig. 3)
²Drill motor with 3M RolocyBristle Disc (white
or yellow) (Fig. 3)
CAUTION: Excessive pressure or high RPM (beyond
the recommended speed), can damage the sealing
surfaces. The mild (white, 120 grit) bristle disc is
recommended. If necessary, the medium (yellow, 80
grit) bristle disc may be used on cast iron surfaces
with care.
STANDARD PROCEDURE - MEASURING
BEARING CLEARANCE USING PLASTIGAGE
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:
(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. 4). (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 with the metricscale provided on the package. Locate the band clos-
est to the same width. This band shows the amount
of clearance in thousandths of a millimeter. Differ-
ences in readings between the ends indicate the
amount of taper present. Record all readings taken.
Compare clearance measurements to specs found in
engine specifications (Refer to 9 - ENGINE - SPECI-
FICATIONS).Plastigage generally is accompa-
nied by two scales. One scale is in inches, the
other is a metric scale.
Fig. 3 PROPER TOOL USAGE FOR SURFACE
PREPARATION
1 - ABRASIVE PAD
2 - 3M ROLOCYBRISTLE DISC
3 - PLASTIC/WOOD SCRAPER
Fig. 4 Plastigage Placed in Lower ShellÐTypical
1 - PLASTIC GAUGE
RSENGINE 2.4L9-11
ENGINE 2.4L (Continued)

NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
(4) Install the proper crankshaft bearings to
achieve the specified bearing clearances. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT MAIN
BEARINGS - STANDARD PROCEDURE) (Refer to 9
- ENGINE/ENGINE BLOCK/CONNECTING ROD
BEARINGS - STANDARD PROCEDURE)
REMOVAL - ENGINE ASSEMBLY
(1) Perform fuel pressure release procedure (Refer
to 14 - FUEL SYSTEM/FUEL DELIVERY - STAN-
DARD PROCEDURE)
(2) Disconnect battery negative cable.
(3) Remove air cleaner housing and inlet tube.
(4) Disconnect the fuel line from fuel rail. (Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- STANDARD PROCEDURE)
(5) Disconnect all vacuum hoses.
(6) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(7) Remove radiator fans. (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL)
(8) Remove radiator upper and lower hoses.
(9) Disconnect automatic transmission cooler lines
and plug.(10) Disconnect transmission shift linkage and
electrical connectors.
(11) Disconnect throttle body linkage.
(12) Disconnect engine wiring harness.
(13) Disconnect heater hoses from heater (Fig. 5).
(14) Discharge air conditioning system. (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE)
(15) Hoist vehicle and remove front wheels and
tires.
(16) Remove accessory drive belt splash shield.
(17) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(18) Remove axle shafts. (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/HALF SHAFT - REMOVAL)
(19) Drain engine oil and remove oil filter. (Refer
to 9 - ENGINE/LUBRICATION/OIL - STANDARD
PROCEDURE)
(20) Remove crossmember cradle plate (Fig. 6).
(21) Disconnect exhaust pipe from manifold (Fig.
7).
(22) Remove engine front mount and bracket from
engine. (Refer to 9 - ENGINE/ENGINE MOUNTING/
FRONT MOUNT - REMOVAL)
(23) Remove structural collar. (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCTURAL COVER -
REMOVAL)
Fig. 5 HEATER HOSES - 2.4L
1 - HEATER HOSES TO HEATER 3 - HEATER HOSE TO ENGINE - SUPPLY AND RETURN
2 - BOLT - HEATER TUBE SUPPORT
9 - 12 ENGINE 2.4LRS
ENGINE 2.4L (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
OIL PRESSURE
DROP1. Low oil level. 1. Check engine oil level.
2. Faulty oil pressure sending unit. 2. Install new sending unit.
3. Low oil pressure. 3. Check sending unit and main bearing oil
clearance.
4. Clogged oil filter. 4. Install new oil filter.
5. Worn parts in oil pump. 5. Replace worn parts or pump.
6. Thin or diluted oil. 6. Change oil to correct viscosity.
7. Oil pump relief valve stuck. 7. Remove valve and inspect, clean, or
replace.
8. Oil pump suction tube loose. 8. Remove oil pan and install new tube or
clean, if necessary.
9. Oil pump cover warped or cracked. 9. Install new oil pump.
10. Excessive bearing clearance. 10. Measure bearings for correct clearance.
OIL LEAKS 1. Misaligned or deteriorated gaskets. 1. Replace gasket(s).
2. Loose fastener, broken or porous metal
part.2. Tighten, repair or replace the part.
3. Misaligned or deteriorated cup or
threaded plug.3. Replace as necessary.
OIL
CONSUMPTION
OR SPARK
PLUGS FOULED1. PCV system malfunction. 1. Check system and repair as necessary.
(Refer to 25 - EMISSIONS CONTROL/
EVAPORATIVE EMISSIONS/PCV VALVE -
DIAGNOSIS AND TESTING)
2. Worn, scuffed or broken rings. 2. Hone cylinder bores. Install new rings.
3. Carbon in oil ring slots. 3. Install new rings.
4. Rings fitted too tightly in grooves. 4. Remove rings and check grooves. If
groove is not proper width, replace piston.
5. Worn valve guide(s). 5. Replace cylinder head assembly.
6. Valve stem seal(s) worn or damaged. 6. Replace seal(s).
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair as necessary.(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.
(5)If the oil leak source is not positively
identified at this time, proceed with the air leak
detection test method as follows:
²Disconnect the fresh air hose (make-up air) at
the cylinder head cover and plug or cap the nipple on
the cover.
²Remove the PCV valve hose from the cylinder
head cover. Cap or plug the PCV valve nipple on the
cover.
²Attach an air hose with pressure gauge and reg-
ulator to the dipstick tube.
CAUTION: Do not subject the engine assembly to
more than 20.6 kpa (3 PSI) of test pressure.
RSENGINE 3.3/3.8L9-77
ENGINE 3.3/3.8L (Continued)

the cylinder in question.The recommended com-
pression pressures are to be used only as a
guide to diagnosing engine problems. An engine
should not be disassembled to determine the
cause of low compression unless some malfunc-
tion is present.
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
The combustion pressure leakage test provides an
accurate means for determining engine condition.
Combustion pressure leakage testing will detect:
²Exhaust and intake valve leaks (improper seat-
ing).
²Leaks between adjacent cylinders or into water
jacket.
²Any causes for combustion/compression pressure
loss.
WARNING: DO NOT REMOVE THE RADIATOR CAP
WITH THE SYSTEM HOT AND UNDER PRESSURE
BECAUSE SERIOUS BURNS FROM COOLANT CAN
OCCUR.
Check the coolant level and fill as required. DO
NOT install the radiator cap.
Start and operate the engine until it attains nor-
mal operating temperature, then turn the engine
OFF.
Clean spark plug recesses with compressed air.
Remove the spark plugs.
Remove the oil filler cap.
Remove the air cleaner.
Calibrate the tester according to the manufactur-
er's instructions. The shop air source for testing
should maintain 483 kPa (70 psi) minimum, 1,379
kPa (200 psi) maximum, with 552 kPa (80 psi) rec-
ommended.
Perform the test procedures on each cylinder
according to the tester manufacturer's instructions.
While testing, listen for pressurized air escaping
through the throttle body, tailpipe and oil filler cap
opening. Check for bubbles in the radiator coolant.
All gauge pressure indications should be equal,
with no more than 25% leakage per cylinder.
FOR EXAMPLE:At 552 kPa (80 psi) input pres-
sure, a minimum of 414 kPa (60 psi) should be main-
tained in the cylinder.
STANDARD PROCEDURE - MEASURING
BEARING CLEARANCE USING PLASTIGAGE
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:(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 with the metric
scale provided on the package. Locate the band clos-
est to the same width. This band shows the amount
of clearance in thousandths of a millimeter. Differ-
ences in readings between the ends indicate the
amount of taper present. Record all readings taken.
Compare clearance measurements to specs found in
engine specifications (Refer to 9 - ENGINE - SPECI-
FICATIONS).Plastigage generally is accompa-
nied 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.
(4) Install the proper crankshaft bearings to
achieve the specified bearing clearances. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT MAIN
BEARINGS - STANDARD PROCEDURE) (Refer to 9
- ENGINE/ENGINE BLOCK/CONNECTING ROD
BEARINGS - STANDARD PROCEDURE)
STANDARD PROCEDURE - FORM-IN-PLACE
GASKETS AND SEALERS
There are numerous places where form-in-place
gaskets are used on the engine. Care must be taken
Fig. 3 Plastigage Placed in Lower ShellÐTypical
1 - PLASTIC GAUGE
RSENGINE 3.3/3.8L9-79
ENGINE 3.3/3.8L (Continued)