position DAEWOO MATIZ 2003 Service Repair Manual

HYDRAULIC BRAKES 4A–5
DAEWOO M-150 BL2
WARNING LAMP OPERATION
This brake system uses a BRAKE warning lamp located
in the instrument panel cluster. When the ignition switch
is in the III position, the BRAKE warning lamp should
glow and then go OFF when the ignition switch returns
to the II position.The following conditions will activate the BRAKE lamp:

Parking brake applied. The light should be on when-
ever the parking brake is applied and the ignition
switch is II.

Low fluid level. A low fluid level in the master cylinder
will turn the BRAKE lamp ON.
BRAKE SYSTEM FAULT
Condition Probable cause Correction
Brake Warning Lamp ON
Brake fluid leaks.
Repair the leaks or add th fluid.

Parking brake switch shorted to
ground.
Repair the short ground.

Faulty the fluid level sensor.
Replace the sensor.
Stoplamp ON
Faulty the stoplamp switch.
Replace the stoplamp switch.

Push rod length is short.
Adjust the push rod length of the
power booster.

Stoplamp switch circuit shorted to
battery.
Repair or Replace the wiring harness.
Poor Braking
Brake fluid lacks or leaks.
Repair the leaks or add the fluid.

Brake fluid contamination.
Replace the fluid.

Air in the brake system.
Bleed the brake system.

Damaged brake lines.
Replace the brake lines.

Damaged vacuum hose or faulty
check valve.
Replace the vacuum hose or check
value.
Dragging Brake
No free play at the brake pedal.
Adjust the free play.

Weakened the brake pedal return
spring.
Replace the return spring.

Faulty master cylinder.
Replace the master cylinder.

Air in the brake system.
Bleed the brake system.
Pedal Over Stroke
Brake fluid lacks or leaks.
Repair the leaks or add the fluid.

Poor adjustment of the brake pedal
free play.
Adjust the push rod length of the
power booster.

4C – 2 POWER BOOSTER
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
POWER BOOSTER
This booster is a single diaphragm, vacuum-suspended
unit. In a normal operating mode, with the service brakes
in the release position, a vacuum-suspended booster
operates with a vacuum on both sides of its diaphragm.
When the brakes are applied, air at atmospheric pres-
sure is admitted to one side of the diaphragm to pro-vide the power assist. When the brakes are released, at-
mospheric air is shut off from that side of the diaphragm.
The air is then drawn from the booster through the vacu-
um check valve by the vacuum source.
Important: If any hydraulic component is removed or
disconnected, it may be necessary to bleed all or part of
the brake system.

POWER BOOSTER 4C–3
DAEWOO M-150 BL2
DIAGNOSTIC INFORMATION AND PROCEDURES
POWER BOOSTER FUNCTIONAL
CHECK
1. With the engine stopped, eliminate the vacuum in the
booster by pumping the brake pedal several times.
2. Push the pedal down and hold it in this position.
3. Start the engine.
4. The booster is OK if the pedal drops further because
of extra force produced.
If the brake pedal does not drop, the vacuum system
(vacuum hoses, check valve, etc.) is probably defective
and should be checked.
If no defect is revealed by checking the vacuum system,
the defect is in the booster itself.
CHECK VALVE FUNCTIONAL CHECK
1. Remove the vacuum hose.
2. Suck the vacuum hose to power booster. And also,
suck the vacuum hose to engine.
3. If the air pass through the check valve or not, replace
the check valve. And if the vacuum hose to engine isonly sucked, the check valve OK.
D17A301B

4D – 2 FRONT DISC BRAKES
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
DISC BRAKE CALIPER ASSEMBLY
This caliper has a single bore and is mounted to the
steering knuckle with two mounting bolts. Hydraulic
pressure, created by applying the brake pedal, is con-
verted by the caliper to a stopping force. This force acts
equally against the piston and the bottom of the caliper
bore to move the piston outward and to slide the caliper
inward, resulting in a clamping action on the rotor. This
clamping action forces the linings against the rotor,
creating friction to stop the vehicle.
D17B001A
Important:

Replace all components included in the repair kits
used to service this caliper.

Lubricate the rubber parts with clean brake fluid to
ease assembly.

Do not use lubricated shop air on brake parts, as
damage to the rubber components may result.

If any hydraulic component is removed or discon-
nected, it may be necessary to bleed all or part of the
brake system.

Replace the pads in axle sets only.

The torque values specified are for dry, unlubricated
fasteners.

Perform the service operations on a clean bench, free
from all mineral oil materials.
CLEARANCE CALIBRATION
When the hydraulic pressure is applied to the piston, the
piston moves leftward. The piston seal, which extent
considerable pressure against the piston, moves with
cylinder.
However, as a part of the piston seal is fixed into a grove
in the cylinder shape of the seal is as shown in below
figure, distorted toward the piston moving direction.
When the pressure is taken off from the brake pedal and
the hydraulic pressure is released from the piston, a re-
storing elastic force is generated at the seal and pushes
the piston rightward and back it in original position.
As the pads wear away and the clearance between rotor
and pads becomes larger, the piston moves larger.
The seal then could change in shape further, but since
end of the seal is fixed into the groove in the cylinder, the
distortion is limited to the same amount as previously
described.
The piston moves further to cover the distance of clear-
ance. As the piston returns by the same distance and
the rubber seal recovers its original shape, the clear-
ance between the rotor and pads is maintained in origi-
nal condition.
1. Piston
2. Piston Seal
3. Pads
a. Clearance
D107B002

FRONT DISC BRAKES 4D–5
DAEWOO M-150 BL2
LINING INSPECTION
1. Raise and suitably support the vehicle.
2. Remove the front wheels. Refer to Section 2E, Tires
and Wheels.
3. Visually check the linings for minimum thickness and
wear.
4. Measure the thickness.
Important: The minimum thickness of the shoe and lin-
ing together is 8 mm (0.31 in.).
D107B301
5. Install the shoe and linings in axle sets only.
6. Install the front wheels. Refer to Section 2E, Tires
and Wheels.
7. Lower the vehicle.
ROTOR INSPECTION
Thickness variation can be checked by measuring the
thickness of the rotor at four or more points around the
circumference of the rotor. All measurements must be
made at the same distance in from the edge of the rotor.
If the thickness of the rotor is below 10 mm (0.40 in.),
replace the brake rotor.
During manufacturing, the brake rotor and the toler-
ances of the braking surface regarding flatness and lat-
eral runout are held very close. The maintenance of
close tolerances on the shape of the braking surfaces is
necessary to prevent brake roughness.
D107B302
In addition to these tolerances, the surface finish must
be held to a specified range. The control of the braking
surface finish is necessary to avoid pulls and erratic per-
formance and to extend lining life.
Using a commercially-available dial indicator, check lat-
eral runout as follows:
Notice: Permissible lateral runout is a maximum 0.05 mm
(0.002 in.). If lateral runout exceeds the specification,
ensure there is no dirt between the rotor and the hub and
that contact surfaces are smooth and free from burrs.
1. Position the transaxle in NEUTRAL.
2. Remove the rotor. Refer to “Rotor” in this section.
3. Fasten a dial indicator to the strut.
4. Set the gauge probe tip to approximately 10 mm
(0.4 in.) from the outer edge of the brake rotor, per-
pendicular to the disc and under slight preload.
5. Remove the dial indicator.
Important: Since accurate control of the rotor toler-
ances is necessary for proper performance of the disc
brakes, refinishing of the rotor should be done only with
precision equipment.
6. Refinish the rotor, if required, with precision equip-
ment. Discard the rotor if it fails to meet the above
specifications after refinishing.
7. Install the rotor. Refer to “Rotor” in this section.
D107B303

FRONT DISC BRAKES 4D–11
DAEWOO M-150 BL2
SPECIFICATIONS
GENERAL SPECIFICATIONS

Application

Unit

Description
Outer Diameter

mm (in.)

236 (9.3)
Thickness

mm (in.)

12.7 (0.5) Rotor
Discard Thickness

mm (in.)

10 (0.4)
Runout

mm (in.)

0.05 (0.002)
Pad Thickness

mm (in.)

10 (0.40)
Caliper

Pad Discard Thickness

mm (in.)

8 (0.31)
Diameter of the Position

mm (in.)

48 (1.89)
FASTENER TIGHTENING SPECIFICATIONS
Application Nm Lb-Ft Lb-In Rotor Bolts 65 48 – Caliper Mounting Bolts 95 70 – Pin Bolts 26 19 – Brake Hose Coupling Bolt 25.5 19.1 – Bleeder Screw 6 – 53

4E – 2 REAR DRUM BRAKES
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
DRUM BRAKES
This drum brake assembly is a leading/trailing shoe de-
sign. Both brake shoes are held against the wheel cylin-
der pistons by the lower return spring and the fixed
anchor plate near the lower return spring. When the
brakes are applied, the wheel cylinder pistons move
both shoes out to contact the drum. With forward wheel
rotation, the forward brake shoe will wrap into the drum
and become self-energized. With reverse wheel rota-
tion, the rear brake shoe is self-energized. Force from
the brake shoes is transferred to the anchor plate
through the backing plate to the axle flange. Adjustment
is automatic and occurs on any service brake applica-
tion. Do not switch the position of shoes that have been
in service, as this may render the self-adjustment fea-
ture inoperative and result in increased pedal travel.Notice:

Replace all the components included in the repair kits
used to service this drum brake.

Do not use lubricated shop air on the brake parts, as
damage to the rubber components may result.

If any hydraulic component is removed or discon-
nected, it may be necessary to bleed all or part of the
braking system.

The torque values specified are for dry, unlubricated
fasteners.

Perform service operations on a clean bench that is
free from all mineral oil materials.

4F–4 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
feed back to the master cylinder and brake pedal.
D107E005
Return Pump Motor
The motor drives two pump elements through the ec-
centric wheel on its shaft.
Return Pump
Description: Each pump element consists of a fixed
displacement piston driven by an eccentric on the end of
the eccentric motor. It has two check valves (inlet and
outlet) and is fed with fluid by the low pressure accumu-
lator.
Operation:
Compression stroke: the pump is filled via the inlet ball
seat, then the motor eccentric rotates moving the piston
to displace the fluid. After the pressure build-up closes
the inlet valve the piston displacement increases the
pressure until the outlet ball opens. The outlet pressure
will continue to increase for the rest of the piston stroke.
Return Stroke: The piston retracts, forced by its spring,
as the motor eccentric returns to its low end position.
The pressure at the inlet side of the outlet ball then de-
creases due to the displaced volume and the pressure
difference across this ball holds it closed.
The pressure at the outlet side of the inlet ball seat,
which is set to open at a certain pressure level also de-
creases until this valve opens. With the outlet ball
closed, the pump is filled with additional fluid from the
low pressure accumulator.
The pressure will continue until a stall point is reached
and compression of the piston cannot generate enough
differential pressure anymore to open the outlet ball
seat.
D17E006A
Return Pump
Return Pump
Motor(0.12~0.16 in.)
EBCM (ELECTRONIC BRAKE
CONTROL MODULE)
Notice: There is no serviceable. The EBCM must be re-
placed as an assembly.
The EBCM is attached to the hydraulic unit in the engine
compartment. The controlling element of ABS is a mi-
croprocessor-based EBCM. Inputs to the system in-
clude 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 M of the assembly line diagnostic link
(ALDL), for service diagnostic tools and assembly plat
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
dump valve to reduce brake pressure to the wheel ap-
proaching lockup. Once the wheel regains traction,
brake pressure is increased until the wheel again begins
to approach lockup. The 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 (ex-
cept the serial data link), and each output for proper op-
eration. If it detects any system malfunction, the EBCM
will store a DTC in nonvolatile memory (DTCs will not
disappear if the battery is disconnected).

ANTILOCK BRAKE SYSTEM 4F–7
DAEWOO M-150 BL2
HYDRAULIC FLUID FLOW DIAGRAMS
Master Cylinder
High Pressure Attenuator
High Pressure Attenuator
Return Pump Motor
Return Pump Return Pump
RR
Isolation Valve
Low
Pressure
AccumulatorFL
Isolation Valve
RR Dump ValveFL
Dump
ValveFR
Isolation Valve
Low Pressure
Accumulator
FR Dump ValveRL
Dump
ValveRL
Isolation
Valve
RR FL FR RL
D17E205A
NORMAL BRAKE MODE
During non-antilock braking, pressure is applied through the brake pedal and fluid comes from the master cylinder into
the hydraulic unit. The normally open isolation cartridge and normally closed dump cartridge would remain in these
positions to allow fluid pressure to the calipers and the wheel cylinders. And each wheel begins locking.

4G – 2 PARKING BRAKE
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
PARKING BRAKE
This braking system uses a BRAKE warning light lo-
cated in the instrument panel cluster. When the ignition
switch is in the III position, the BRAKE warning light
should glow and go OFF when the parking brake lever is
released. Whenever the parking brake is applied and theignition switch is II, the BRAKE warning light should
glow.
When the brake is firmly applied, the parking brake
should securely hold the vehicle with ample pedal travel
remaining. Check for frayed cables, rust, etc., or any
condition that may inhibit present (or future) free move-
ment of the parking brake lever assembly.