2003 DAEWOO MATIZ low oil pressure

4B –2 MASTER CYLINDER
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
MASTER CYLINDER
The master cylinder is designed for use in a direct–split
system. Front right brake and rear left brake are served
by the primary piston. Front left brake and rear right
brake are served by the secondary piston.
The master cylinder incorporates the functions of the
standard dual master cylinder, plus a low fluid level indi-
cator and the proportioning valve in the non–antilock
braking system.
The proportioning valves limit the outlet pressure to the
rear brakes after a predetermined master cylinder has
been reached.
Important:

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

Lubricate rubber parts with clean brake fluid to ease
assembly.

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

If any hydraulic component is removed or discon-
nected, it may be necessary to bleed all or part of the
brake system.
The torque values specified are for dry, unlubricated
fasteners.

Perform all service operations on a clean bench, free
from all traces of mineral oil.
PROPORTIONING VALVE
The proportioning valve limits the outlet pressure to the
rear brakes on the non-ABS after a predetermined mas-
ter cylinder pressure has been reached. This is used
when less rear apply force is needed to obtain optimum
braking and is usually found on disc/drum brake configu-
rations. On ABS-equipped vehicles, refer to Section 4F,
Antilock Brake System.
FLUID LEVEL SENSOR
Fluid level sensor is attached at the brake fluid reservoir.
This sensor will activate the BRAKE light if a low fluid
level condition is detected. Once the fluid level is cor-
rected, the BRAKE light will go out.

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

ANTILOCK BRAKE SYSTEM 4F–3
DAEWOO M-150 BL2
DESCRIPTION AND OPERATION
ABS SYSTEM COMPONENTS
The Antilock Braking System (ABS) consists of a con-
ventional hydraulic brake system plus antilock compo-
nents. The conventional brake system includes a
vacuum booster, master cylinder, front disc brakes, rear
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, and the rear drum
brake. See “ABS Component Locator” in this section for
the general layout of this system.
HYDRAULIC UNIT
The hydraulic unit with the attached EBCM is located
between the surge tank and the fire wall on the right side
of the vehicle. The basic hydraulic unit configuration
consists of return pump motor, return pump, four isola-
tion valves, four dump valves, two Low Pressure Accu-
mulators (LPA), two High Pressure Attenuators (HPA).
The hydraulic unit controls hydraulic pressure to the
front calipers and rear wheel cylinders by modulating hy-
draulic pressure to prevent wheel lockup.
Isolation valve
The isolation valve is placed in the brake fluid path from
the master cylinder to the relevant brake caliper and al-
lows free flow as commanded by the driver during nor-
mal braking and reapply phases.
In the isolation phase the coil moves the armature down,
which closes the normally open isolation orifice and pre-
vents any further increase of pressure in the brake. The
valve also remains closed during the dump phase.
The lip seal provides a one way return path for brake
fluid to flow through in:
1. Foot off pedal during isolation.
2. Residual LPA fluid.
D107E002
Dump Valve
The dump valve creates a flow path from the isolation
cartridge (brake side) to the low pressure accumulator
(LPA). The valve keeps this path permanently closed ex-
cept during the dump phase in the ABS mode. On ac-
tivation (dump phase), the coil moves up the armature
which opens the normally closed dump orifice and allow
to drain the pressure in the brake line with the brake fluid
flowing into the LPA.
The lip seal provides a return path for residual brake
fluid in the LPA.
D107E003
Low Pressure Accumulator (LPA)
LPA provides a variable chamber for brake fluid to be
quickly pushed in through the dump valve at the begin-
ning of a departure. This chamber then acts as a reser-
voir which buffers the pump.
D107E004
High Pressure Attenuator (HPA)
The HPA is in between the pump and the ISO valve
(master cylinder side) and uses the bulk mode of the
contained plastic damper and orifice size to dump out
the pressure oscillations from the pump to reduce the

4F–8 ANTILOCK BRAKE SYSTEM
DAEWOO M-150 BL2
Master Cylinder
High Pressure Attenuator
High Pressure Attenuator
Return Pump Motor
Return Pump Return Pump
Low
Pressure
Accumulator
Low Pressure
Accumulator
RRFL FR
RL
D17E206A
RR
Isolation ValveFL
Isolation Valve
RR Dump ValveFL
Dump
ValveFR
Isolation Valve
FR Dump ValveRL
Dump
ValveRL
Isolation
Valve
ISOLATION MODE (PRESSURE MAINTAIN)
If the information from the wheel speed sensors indicate excessive wheel deceleration (imminent lockup), the first step
in the antilock sequence is to isolate the brake pressure being applied by the driver. The EBCM sends a voltage to the
coil to energize and close the isolation valves by pulling down on the armature. This prevents any additional fluid pres-
sure applied by the driver from reaching the wheel. Though each channel of the 4-channel system can operate inde-
pendently, once any front channel (brake) sees excessive deceleration, both front isolation valves are energized and
close thus, with the isolation valves closed, further unnecessary increases in the brake pressure will be prohibited.

ANTILOCK BRAKE SYSTEM 4F–9
DAEWOO M-150 BL2
Master Cylinder
High Pressure Attenuator
High Pressure Attenuator
Return Pump Motor
Return Pump Return Pump
Low
Pressure
Accumulator
Low Pressure
Accumulator
RRFL FR
RL
D17E207A
RR
Isolation ValveFL
Isolation Valve
RR Dump ValveFL
Dump
ValveFR
Isolation Valve
FR Dump ValveRL
Dump
ValveRL
Isolation
Valve
DUMP MODE (PRESSURE DECREASE)
Once the pressure is isolated, it must be reduced to get the wheels rolling once again. This is accomplished by dump-
ing a portion of the brake fluid pressure into a low pressure accumulator (LPA).
The EBCM energizes the dump cartage coil(s) to open the dump cartridge, allowing fluid from the wheels to be
dumped into the LPA. This done with very short activation pulses opening and closing the dump cartridge passageway.
Brake pressure is lowered at the wheel and allows the wheel to begin spinning again.
The fluid taken from the wheels forces the spring back and is stored in the LPA. A portion of the fluid also primes the
pump. The dump cartridges are operated independently to control the deceleration of the wheel.

CLUTCH 5C–7
DAEWOO M-150 BL2
D13C5031
4. Remove the transaxle input shaft bearing using the
input shaft bearing remover 09917–58010, the fly-
wheel holder 09924–17810 and a spanner.
D13C5041
Inspection Procedure – Pressure Plate
and Clutch Disc
1. Pressure plate inspection .

Check the weak and damaged diaphragm spring
(1).

Check the polluted face by the oil, grease (2).
D103C505
2. Clutch disc inspection

Measure rivet head depth from clutch disc surface
and replace if below limit.
Unit : mm (in.)
Standard Limit
Rivet Head Depth1.2 (0.047)0.5 (0.02)

Replace the clutch disc if clutch disc surface is
contaminated or clutch disc rivets are loosen.
D103C506
3. Clutch disc runout in rotational direction inspection.

Measure runout in rotational direction and replace
if runout exceeds limit.
Unit : mm (in.)


Disc Runout Limit in Rotational
Direction (Periphery)
0.7 (0.028)

6B –8 POWER STEERING PUMP
DAEWOO M-150 BL2
SPECIFICATIONS
GENERAL SPECIFICATIONS

Application

Description
Lubricant

Power Steering Fluid DEXRON-II, DEXRON-III
Capacity

1.0 Liter (1.056 qt)
Type

Vane
FASTENER TIGHTENING SPECIFICATIONS
Application Nm Lb-Ft Lb-In
Power Steering Pump Bolt 20 – 24 15 – 18 –
Power Steering Pump Front Bracket Bolt 20 – 24 15 – 18 –
Power Steering Pump Front Bracket Adjusting Bolt 18 – 22 13 – 16 –
Power Steering Pump Rear Bracket Upper Bolt 35 – 45 26 – 33 –
Power Steering Pump Rear Bracket Lower Bolt 20 – 24 15 – 18 –
Power Steering Pump Rear Bracket Adjusting Bolt20 – 2415 – 18–
Power Steering Pump Pulley Nut55 – 6941– 51–
Power Steering Oil Pressure Line Fitting21 – 3516 – 26–

DAEWOO M-150 BL2

SECTION 7B
MANUAL CONTROL HEATING, VENTILATION,
AND AIR CONDITIONING SYSTEM
CAUTION: Disconnect the negative battery cable before removing or installing any electrical unit or when a
tool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cable
will help prevent personal injury and damage to the vehicle. The ignition must also be in B unless otherwise
noted.
TABLE OF CONTENTS
Description and Operation 7B-2. . . . . . . . . . . . . . . . . .
System Components – Functional 7B-2. . . . . . . . . . .
Component Locator 7B-3. . . . . . . . . . . . . . . . . . . . . . . .
A/C System 7B-3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Diagnostic Information and Procedures 7B-5. . . . .
General Diagnosis 7B-5. . . . . . . . . . . . . . . . . . . . . . . . . . .
Testing the Refrigerant System 7B-5. . . . . . . . . . . . . .
Insufficient Cooling “Quick Check”
Procedure 7B-5. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Pressure-Temperature Relationship
of R-134a 7B-6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Leak Testing the Refrigerant System 7B-7. . . . . . . . .
Air Conditioning System Diagnosis 7B-8. . . . . . . . . . . . .
Insufficient Cooling Diagnosis 7B-8. . . . . . . . . . . . . . .
Symptom Diagnosis 7B-11. . . . . . . . . . . . . . . . . . . . . . . .
Pressure Test Chart (R-134a System) 7B-11. . . . . . .
Repair Instructions 7B-13. . . . . . . . . . . . . . . . . . . . . . . .
On-Vehicle Service 7B-13. . . . . . . . . . . . . . . . . . . . . . . . .
General A/C System Service Procedures 7B-13. . . . . .
O-Ring Replacement 7B-13. . . . . . . . . . . . . . . . . . . . .
Handling Refrigerant 7B-13. . . . . . . . . . . . . . . . . . . . . .
Handling of Refrigerant Lines and Fittings 7B-13. . .
Maintaining Chemical Stability in the
Refrigeration System 7B-14. . . . . . . . . . . . . . . . . . .
Discharging, Adding Oil, Evacuating, and
Charging Procedures for A/C System 7B-14. . . . . Serviceable Components 7B-17. . . . . . . . . . . . . . . . . . . .
Control Assembly and Control Cables 7B-17. . . . . . .
Blower Motor and Cooling Hose 7B-17. . . . . . . . . . . .
Blower Resistor 7B-17. . . . . . . . . . . . . . . . . . . . . . . . . .
Blower Motor Switch 7B-17. . . . . . . . . . . . . . . . . . . . . .
A/C Push Knob 7B-18. . . . . . . . . . . . . . . . . . . . . . . . . .
Receiver–Dryer and Dual Cut Switch 7B-18. . . . . . . .
Receiver–Dryer Bracket 7B-20. . . . . . . . . . . . . . . . . . .
Compressor 7B-20. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Condenser 7B-21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
A/C High Pressure Pipe Line 7B-22. . . . . . . . . . . . . . .
A/C Low Pressure Pipe Line 7B-25. . . . . . . . . . . . . . .
Evaporator Unit and Drain Hose 7B-26. . . . . . . . . . . .
Unit Repair 7B-28. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Evaporator Core and Expansion Valve 7B-28. . . . . .
Compressor Overhaul 7B-29. . . . . . . . . . . . . . . . . . . . .
Specifications 7B-30. . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Specifications 7B-30. . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 7B-30. . . . . . . . . .
Special Tools and Equipment 7B-31. . . . . . . . . . . . . .
Special Tools Table 7B-31. . . . . . . . . . . . . . . . . . . . . . .
Schematic and Routing Diagrams 7B-32. . . . . . . . . .
A/C Diagrams 7B-32. . . . . . . . . . . . . . . . . . . . . . . . . . . .
A/C Airflow (Typical) 7B-33. . . . . . . . . . . . . . . . . . . . . .
A/C System (Typical) 7B-33. . . . . . . . . . . . . . . . . . . . .