Daewoo Nubira User Manual page 178

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 LOCK unless otherwise noted.
SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . .
FASTENER TIGHTENING SPECIFICATIONS
DIAGNOSIS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CHECKING BRAKE PROPORTIONING VALVE 4B–1
MAINTENANCE AND REPAIR
ON–VEHICLE SERVICE
MASTER CYLINDER ASSEMBLY
BRAKE FLUID RESERVOIR
Application
Brake Lines
Master Cylinder Attaching Nuts
Proportioning Valves
DIAGNOSIS
CHECKING BRAKE
PROPORTIONING VALVE
Use two brake pressure gauges to check the brake pro-
portioning valves that are attached to the master cylinder
on non–ABS braking systems. These valves limit the out-
let pressure to the rear brakes after a predetermined mas-
ter cylinder pressure has been reached. (On ABS braking
systems, the hydraulic modulator/ motor pack assembly
controls the hydraulic pressure to both the rear wheel cyl-
inders or rear calipers, and the front calipers.)
Engine
2.0L
SECTION : 4B
MASTER CYLINDER
TABLE OF CONTENTS
4B–1
. 4B–1
4B–1
. . . . . . . . . . . . . . . 4B–3
. . . . . . . . . . . . . . . . . . . . . 4B–3
. . . . . . . . . . . 4B–3
. . . . . . . . . . . . . . . . 4B–5
SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
Reference Number for
Gradient and Switching
Pressure on the Valve
Housing
0.3/40
5 500 (798)
10 000 (1,450)
PROPORTIONING VALVE
UNIT REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MASTER CYLINDER OVERHAUL
GENERAL DESCRIPTION AND SYSTEM
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
MASTER CYLINDER
PROPORTIONING VALVE
FLUID LEVEL SENSOR
NSm Lb–Ft
16 12
18 13
22 16
When checking the brake proportioning valves, be sure
that the hydraulic line pressure is measured simulta-
neously and diagonally on the front and the rear axles. To
measure the pressure, use the following steps.
1. Remove the bleeder valve and install a pressure
gauge to one of the rear brake cylinders.
2. Install another bleeder valve and install another
pressure gauge to the diagonally opposite front
brake.
3. Build pressure by pressing firmly on the brake ped-
al several times. (The pressure indicated on the
gauge is not regulated and represents the actual
brake system hydraulic pressure.)
4. Build pressure until the test values in the following
proportioning valve test chart are achieved.
Input Pressure Read on
the Manometer at the
Front Axle in kPa (psi)
500 (73)
4 450 ± 200 (645 ± 29)
5 800 ± 300 (841 ± 44)
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . .
4B–11
. . . . . . . . . . . . . . . . . . . . . 4B–11
. . . . . . . . . . . . . . . . . 4B–11
. . . . . . . . . . . . . . . . . . . 4B–11
Lb–In
–
–
–
Output Pressure Read
on the Manometer at the
Front Axle in kPa (psi)
500 (73)
4B–7
4B–8
4B–8