tire pressure DAEWOO LACETTI 2004 Service Owner's Guide

4A – 12IHYDRAULIC BRAKES
DAEWOO V–121 BL4
12. Slowly push and hold the brake pedal one time.
13. Remove the bleeder valve dust cover and loosen
the bleeder screw to purge the air from the cylinder.
14. Tighten the bleeder screw.
Tighten
Tighten the bleeder screw to 8 NSm (71 lb–in).
15. Slowly release the brake pedal. Wait 15 seconds
before proceeding with the next step.
Important : Rapid pumping of the brake pedal pushes the
master cylinder secondary piston down the bore in a man-
ner that makes it difficult to bleed the system.
16. Repeat the sequence, including the 15–second
wait, until all the air is removed. It may be neces-
sary to repeat the sequence 10 or more times to
remove all the air.
17. Locate the front bleeder caps.
18. Proceed to bleed the front brakes following the ap-
propriate sequence, beginning with step 12.
19. Check the brake pedal for sponginess. Repeat the
entire bleeding procedure to correct this condition.
20. Replace the bleeder valve dust cover.
PRESSURE BLEEDING THE BRAKES
Notice : Pressure bleeding equipment must be of the dia-
phragm type. It must have a rubber diaphragm between
the air supply and the brake fluid to prevent air, moisture,
oil, and other contaminants from entering the hydraulic
system. Contamination could lead to deterioration of the
braking components and loss of braking action.
1. Disconnect the master cylinder electrical connector.
2. Remove the master cylinder reservoir cap.
3. Connect the bleeder with the adapter to the master
cylinder reservoir.
4. For vehicles with the antilock braking system
(ABS), locate and remove the hydraulic modulator
bleeder valves. Refer to Section 4F, Antilock Brake
System.
5. Charge the bleeder ball to 140 to 172 kPa (20 to 25
psi).
6. Connect the line to the adapter. Open the line
valve.
7. Raise and suitably support the vehicle.
Important : The bleeding sequence is as follows: right
rear, left front, left rear and right front.

ANTILOCK BRAKE SYSTEM 4F – 65
DAEWOO V–121 BL4
GENERAL DESCRIPTION AND SYSTEM
OPERATION
BASIC KNOWLEDGE REQUIRED
Before using this section, it is important that you have a ba-
sic knowledge of the following items. Without this knowl-
edge, it will be difficult to use the diagnostic procedures
contained in this section.
S Basic Electrical Circuits : You should understand
the basic theory of electricity and know the mean-
ing of voltage, current (amps), and resistance
(ohms). You should understand what happens in a
circuit with an open or shorted wire. You should be
able to read and understand a wiring diagram.
S Use of Circuit Testing Tools : You should know how
to use a test light and how to bypass components
to test circuits using fused jumper wires. You should
be familiar with a digital multimeter. You should be
able to measure voltage, resistance, and current,
and be familiar with the controls and how to use
them correctly.
ABS SYSTEM COMPONENTS
The ABS 5.3 Antilock Braking System (ABS) consists of
a conventional hydraulic brake system plus antilock com-
ponents. The conventional brake system includes a vacu-
um booster, master cylinder, front disc brakes, rear lead-
ing/trailing drum brakes, interconnecting hydraulic brake
pipes and hoses, brake fluid level sensor and the BRAKE
indicator.
The ABS components include a hydraulic unit, an elec-
tronic brake control module (EBCM), two system fuses,
four wheel speed sensors (one at each wheel), intercon-
necting wiring, the ABS indicator, the EBD indicator (which
is connected to the parking lamp) and the rear disk brakes.
See “ABS Component Locator” in this section for the gen-
eral layout of this system.
The hydraulic unit with the attached EBCM is located be-
tween the surge tank and the fire wall on the left side of the
vehicle.
The basic hydraulic unit configuration consists of hydraulic
check valves, two solenoid valves for each wheel, a hy-
draulic pump, two accumulators, and two damper. The hy-
draulic unit controls hydraulic pressure to the front calipers
and rear wheel cylinders by modulating hydraulic pressure
to prevent wheel lockup.
Nothing in the hydraulic unit or the EBCM is serviceable.
In the event of any failure, the entire ABS unit with at-
tached EBCM must be replaced. For more information, re-
fer to ”Base Braking Mode” and ”Antilock Braking Mode”
in this section.
BASE BRAKING MODE
The baseline braking mode of the ABS 5.3 system used
in this vehicle is a diagonal split system. In this system,
one master cylinder circuit supplies pressure to the right
front and the left rear brakes; the other circuit supplies
pressure to the left front and the right rear brakes. All
valves in the hydraulic modulator are in their normal, non–
energized positions as shown in the drawings found in
”ABS System Components” in this section.

ANTILOCK BRAKE SYSTEM 4F – 71
DAEWOO V–121 BL4
TIRES AND ABS/EBD
Replacement Tires
Tire size is important for proper performance of the ABS
system. Replacement tires should be the same size, load
range, and construction as the original tires. Replace tires
in axle sets and only with tires of the same tire perfor-
mance criteria (TPC) specification number. Use of any
other size or type may seriously affect the ABS operation.
TIRES AND ABS/EBD
Notice : There is no serviceable or removable EEPROM.
The EBCM must be replaced as an assembly.
The EBCM is attached to the hydraulic unit in the engine
compartment. The controlling element of ABS 5.3 is a mi-
croprocessor–based EBCM. Inputs to the system include
the four wheel speed sensors, the stoplamp switch, the
ignition switch, and the unswitched battery voltage. There
is an output to a bi–directional serial data link, located in
pin K of Data Link Connector (DLC) for service diagnostic
tools and assembly plant testing.
The EBCM monitors the speed of each wheel. If any wheel
begins to approach lockup and the brake switch is closed
(brake pedal depressed), the EBCM controls the sole-
noids to reduce brake pressure to the wheel approaching
lockup. Once the wheel regains traction, brake pressure
is increased until the wheel again begins to approach lock-
up. This cycle repeats until either the vehicle comes to a
stop, the brake pedal is released, or no wheels approach
lockup.
Additionally, the EBCM monitors itself, each input (except
the serial data link), and each output for proper operation.
If it detects any system malfunction, the EBCM will store
a DTC in nonvolatile memory (EEPROM) (DTCs will not
disappear if the battery is disconnected). Refer to ”Self
Diagnostics” in this section for more detailed information.
FRONT WHEEL SPEED SENSOR
The front wheel speed sensors are of a variable reluctance
type. Each sensor is attached to the steering knuckle,
close to a toothed ring. The result, as teeth pass by the
sensor, is an AC voltage with a frequency proportional to
the speed of the wheel. The magnitude of the voltage and
frequency increase with increasing speed. The sensor is
not repairable, nor is the air gap adjustable.
FRONT WHEEL SPEED SENSOR
RINGS
The toothed ring mentioned above is pressed onto the
wheel–side (outer) constant velocity joint. Each ring con-
tains 47 equally spaced teeth. Exercise care during ser-
vice procedures to avoid prying or contacting this ring. Ex-cessive contact may cause damage to one or more teeth.
If the ring is damaged, the wheel–side constant velocity
joint must be replaced.
REAR WHEEL SPEED SENSOR AND
RINGS
The rear wheel speed sensors operate in the same man-
ner as the front wheel speed sensors. They incorporate a
length of flexible harness with the connector attached to
the end of the harness. The rear wheel speed rings are in-
corporated into the hub assemblies and cannot be re-
placed separately, but require replacement of the rear
hub/bearing assembly.
VALUE RELAY AND PUMP MOTOR
RELAY
The valve relay and the motor pump relay are located in-
side the electronic brake control module (EBCM) and are
not replaceable. If one should fail, replace the EBCM.
WIRING HARNESS
The wiring harness is the mechanism by which the elec-
tronic brake control module (EBCM) is electrically con-
nected to power and to ground, to the wheel speed sen-
sors, the fuses, the switches, the indicators, and the serial
communications port. The components, considered part
of the wiring harness, are the wires that provide electrical
interconnection, and connectors (terminals, pins, con-
tacts, or lugs) that provide an electrical/mechanical inter-
face from the wire to a system component.
INDICATORS
The electronic brake control module (EBCM) continuously
monitors itself and the other ABS components. If the
EBCM detects a problem with the system, the amber ABS
indicator will light continuously to alert the driver to the
problem. An illuminated ABS indicator indicates that the
ABS system has detected a problem that affects the op-
eration of ABS. No antilock braking will be available. Nor-
mal, non–antilock brake performance will remain. In order
to regain ABS braking ability, the ABS must be serviced.
The red BRAKE indicator will be illuminated when the sys-
tem detects a low brake fluid level in the master cylinder
or when the parking brake switch is closed (the parking
brake is engaged) or EBD system is diabled.
WARNING : EBD INDICATOR LAMP WIRING IS CON-
NECTED TO THE PARKING BRAKE LAMP. IF THE
PARKING BRAKE LAMP IS TURNED ON WHEN YOU
DRIVING, CHECKING ON WHETHER THE PARKING
BRAKE LEVER IS ENAGED OR THE BRAKE FLUID
LEVEL IS LOW. IF THE SYSTEM HAS NO PROBLEM,
THE EBD SYSTEM IS WORKING IMPROPERLY. THE
EBD SYSTEM MUST BE SERVICED.

FIVE–SPEED MANUAL TRANSAXLE 5B – 5
DAEWOO V–121 BL4
DIAGNOSIS
ISOLATE NOISE
Identify the cause of any noise before attempting to repair
the clutch, the transaxle, or their related link–ages.
Symptoms of trouble with the clutch or the manual trans-
axle include:
S A great effort required to shift gears.
S The sound of gears clashing and grinding.
S Gear blockout.
Any of these conditions requires a careful analysis. Make
the following checks before disassembling the clutch or
the transaxle for repairs.
Road Travel Noise
Many noises that appear to come from the transaxle may
actually originate with other sources such as the:
S Tires.
S Road surfaces.
S Wheel bearings.
S Engine.
S Exhaust system.
These noises may vary according to the:
S Size of the vehicle.
S Type of the vehicle.
S Amount of insulation used in the body of the ve-
hicle.
Transaxle Noise
Transaxle gears, like any mechanical device, are not ab-
solutely quiet and will make some noise during normal op-
eration.
To verify suspected transaxle noises:
1. Select a smooth, level asphalt road to reduce tire
and resonant body noise.
2. Drive the vehicle far enough to warm up all the lu-
bricants thoroughly.
3. Record the speed and the gear range of the trans-
axle when the noise occurs.
4. Check for noises with the vehicle stopped, but with
the engine running.
5. Determine if the noise occurs while the vehicle op-
erates in:
S Drive – under a light acceleration or a heavy
pull.
S Float – maintaining a constant speed with a light
throttle on a level road.
S Coast – with the transaxle in gear and the
throttle partly or fully closed.
S All of the above.
Bearing Noise
Differential Side Bearing Noise
Differential side bearing noise and wheel bearing noise
can be confused easily. Since side bearings are pre–
loaded, a differential side bearing noise should not dimin-
ish much when the differential/transaxle is run with the
wheels off the ground.
Wheel Bearing Noise
Wheel bearings produce a rough growl or grating sound
that will continue when the vehicle is coasting and the
transaxle is in NEUTRAL. Since wheel bearings are not
pre–loaded, a wheel bearing noise should diminish con-
siderably when the wheels are off the ground.
Other Noise
Brinelling
A brinelled bearing causes a ”knock” or ”click” approxi-
mately every second revolution of the wheel because the
bearing rollers do not travel at the same speed as the
wheel. In operation, the effect is characterized by a low–
pitched noise.
A brinelled bearing is caused by excessive thrust which
pushes the balls up on the pathway and creates a triangu-
lar–shaped spot in the bearing race. A brinelled bearing
can also be caused from pressing one race into position
by applying pressure on the other race.
A false indication of a brinelled bearing occurs as a result
of vibration near the area where the bearing is mounted.
Brinelling is identified by slight indentations, resulting in a
washboard effect in the bearing race.
Lapping
Lapped bearing noise occurs when fine particles of abra-
sive materials such as scale, sand, or emery circulate
through the oil in the vehicle, causing the surfaces of the
roller and the race to wear away. Bearings that wear loose
but remain smooth, without spalling or pitting, are the re-
sult of dirty oil.
Locking
Large particles of foreign material wedged between the
roller and the race usually causes one of the races to turn,
creating noise from a locked bearing. Pre–loading regular
taper roller bearings to a value higher than that specified
also can result in locked bearings
Pitting
Pitting on the rolling surface comes from normal wear and
the introduction of foreign materials.
Spalling
Spalled bearings have flaked or pitted rollers or races
caused by an overload or an incorrect assembly that re-
sults in a misalignment, a cocking of bearings, or adjust-
ments that are too tight.
After completing these checks, refer to the ”Diagnosis
Chart” in this section.

7B – 52IMANUAL CONTROL HEATING, VENTILATION AND AIR CONDITIONING SYSTEM
DAEWOO V–121 BL4
SYSTEM COMPONENTS–CONTROL
Controller
The operation of the A/C system is controlled by the
switches and the lever on the control head. The compres-
sor clutch and the blower are connected electrically to the
control head by a wiring harness. The blower circuit is
open in the OFF mode. Airflow is provided by the four
blower speeds available in the remaining modes. Cooled
and dehumidified air is available in the MAX, NORMAL,
BI–LEVEL, and DEFROST modes.
The temperature is controlled by the position of the tem-
perature knob on the control head. A cable connects this
knob to the temperature door, which controls the airflow
through the heater core. As the temperature knob is
moved through its range of travel, a sliding clip on the
cable at the temperature valve connection should assume
a position ensuring that the temperature door will seat in
both extreme positions. The temperature door position is
independent of the mode control switch. The temperature
door on some models is controlled electrically, eliminating
the need for the temperature cable.
The electric engine cooling fan on some vehicles is not
part of the A/C control system; however, the fan is opera-
tional any time the A/C control is in the MAX, NORMAL,
or BI–LEVEL modes. Some models provide for engine
cooling fan operation when the controller is in the DE-
FROST mode. This added feature is part of the A/C con-
troller function and is aimed at preventing excessive com-
pressor head temperatures. It also allows the A/C system
to function more efficiently. On some models, the engine
cooling fan will be turned off during road speed conditions
above 56 km/h (35 mph), when the airflow though the con-
denser coil is adequate for efficient cooling. The operation
of the cooling fan is controlled by the powertrain control
module (PCM), or the engine control module (ECM),
through the cooling fan relay.
Pressure Transducer
The pressure transducer incorporates the functions of the
high–pressure and the low–pressure cutout switches
along with the fan cycling switch. The pressure transducer
is located in the high–side liquid refrigerant line near the
right front strut tower and the air filter assembly.
Wide–Open Throttle (WOT) Compressor
Cutoff
During full throttle acceleration on vehicles equipped with
multi–port injection (MPI), the throttle position sensor
(TPS) sends a signal to the PCM or the ECM, which then
controls the compressor clutch.
A/C Time Delay Relay
This relay on some vehicles controls the current to the en-
tire A/C system and provides a short delay of A/C opera-
tion upon start–up.
V5 COMPRESSOR–GENERAL
DESCRIPTION
Different vehicles with V5 compressors may exhibit differ-
ences in mounting and installation, but overhaul proce-
dures are similar.
Before removing the compressor or performing on–ve-
hicle repairs, clean the compressor connections and the
outside of the compressor.
Important : After removing a compressor from the vehicle
for servicing, drain the oil by removing the oil drain plug.
Also drain the oil from the suction and the discharge ports
to insure complete draining. Measure the amount of oil
drained, and record that amount. Discard the used oil and
add the same amount of new polyalkaline glycol (PAG) re-
frigerant oil to the compressor.
The compressor has been removed from the vehicle un-
less otherwise indicated.
Clean tools and a clean work area are important for proper
servicing. Keep dirt and foreign material from getting on or
into the compressor parts. Parts that are to be reassem-
bled should be cleaned with trichloroethane, naphtha,
stoddard solvent, kerosene, or equivalent solvents. Dry
the cleaned parts with clean dry air. Use only lint–free
cloths to wipe the parts.
V5 COMPRESSOR–DESCRIPTION OF
OPERATION
The V5 is a variable displacement compressor that can
match the automotive air conditioning (A/C) demand un-
der all conditions without cycling. The basic compressor
mechanism is a variable angle wobble–plate with five ax-
ially oriented cylinders. The center of control of the com-
pressor displacement is a bellows–actuated control valve
located in the rear head of the compressor. The control
valve senses compressor suction pressure.
The wobble–plate angle and the compressor displace-
ment are controlled by the crankcase suction pressure dif-
ferential. When the A/C capacity demand is high, the suc-
tion pressure will be above the control point. The valve will
maintain a bleed from crankcase to suction. With no
crankcase suction pressure differential, the compressor
will have maximum displacement.
When the A/C capacity demand is lower and the suction
pressure reaches the control point, the valve will bleed dis-
charge gas into the crankcase and close off a passage
from the crankcase to the suction plenum. The angle of the
wobble–plate is controlled by a force balance on the five
pistons. A slight elevation of the crankcase suction pres-
sure differential creates total force on the pistons resulting
in a movement about the wobbleplate pivot pin that re-
duces the plate angle.
The compressor has a unique lubrication system. The
crankcase suction bleed is routed through the rotating
wobble–plate for lubrication of the wobble–plate bearing.
The rotation acts as an oil separator which removes some

9I – 2IWATERLEAKS
DAEWOO V–121 BL4
DIAGNOSIS
WATERLEAK DIAGNOSIS
The repair of waterleaks in the body requires proper test-
ing and diagnosis. Repair waterleaks by adjusting the mis-
aligned parts and using the proper repair materials. First,
determine what conditions cause the leak. For example,
the leak may occur only when the vehicle is parked on an
incline, or water may appear only in the spare tire compart-
ment. Second, test the area for the source of the leak us-
ing the following testing methods. If the general leak area
is found, determine the exact entry point of the leak by us-
ing a water hose or an air hose. If the general leak area is
not obvious, use the watertest stands to determine the
area of the leak. It may be necessary to remove some inte-
rior trim panels or some parts in order to locate the leaks.
Important : It is necessary to find the origin of all the leaks
before making any repairs. Random repairs may stop the
leak only temporarily and may make future repairs more
difficult. Continue localized testing in the general area in
order to ensure that all leaks are found.
Generalized Testing
1. Set up the watertest stands.
1) 1/2–inch by 36–inch Pipe
2) Full–jet Spray Nozzle #1/2 GG–25 or Equiva-
lent Nozzle Height at 1,600 mm to the Floor
3) 1/2–inch Coupling
4) 1/2–inch by 1/2–inch by 1/4–inch Reducing T
(Right Only)
5) 1/2–inch Coupling (Left Only)
6) 1/2–inch Cross (Right Only) )
7) 1/2–inch Tee (Left Only)
8) 1/2–inch Pipe–to–Hose Nipple (Right Only)
9) 5/8–inch Female Hose Coupling
10) 5/8–inch Input Hose (2 Feet Long, Right Only
11) 1/2–inch Close Nipple
12) 1/2–inch Cross with Weld–on 1/2–inch Cap
13) 1/2–inch by 12–inch Nipple
14) 1/2–inch Cap
15) 5/8–inch Female Hose Coupling
16) 5/8–inch Cross Hose (12 Feet Long)
17) 5/8–inch Hose Quick Connect
18) 1/2–inch Pipe–to–Hose Nipple
19) 1/2–inch by 30–inch Pipe (Straight)
20) 1/4–inch Water Pressure Gauge (Right Only)
2. Set up the watertest stand leak test.