Checking Brake Proportioning Valve DAEWOO NUBIRA 2004 Service Repair Manual

SECTION : 4B
MASTER CYLINDER
TABLE OF CONTENTS
SPECIFICATIONS4B–1 . . . . . . . . . . . . . . . . . . . . . . . . . .
Fastener Tightening Specifications 4B–1. . . . . . . . . .
DIAGNOSIS4B–2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checking Brake Proportioning Valve 4B–2. . . . . . . . .
MAINTENANCE AND REPAIR4B–3 . . . . . . . . . . . . . . .
ON–VEHICLE SERVICE 4B–3. . . . . . . . . . . . . . . . . . . . .
Master Cylinder Assembly 4B–3. . . . . . . . . . . . . . . . . . Brake Fluid Reservoir 4B–4. . . . . . . . . . . . . . . . . . . . . .
UNIT REPAIR 4B–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Master Cylinder Overhaul 4B–7. . . . . . . . . . . . . . . . . . .
GENERAL DESCRIPTION AND SYSTEM
OPERATION4B–9 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Master Cylinder 4B–9. . . . . . . . . . . . . . . . . . . . . . . . . . .
Fluid Level Sensor 4B–9. . . . . . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS
FASTENER TIGHTENING SPECIFICATIONS
ApplicationNSmLb–FtLb–In
Brake Lines1612–
Master Cylinder Attaching Nuts1813–
Proportioning Valves2216–

4B – 2IMASTER CYLINDER
DAEWOO V–121 BL4
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.)
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.
Model
Reference Number for
Gradient and Switching
Pressure on the Valve
HousingInput Pressure Read on
the Manometer at the
Front Axle in kPa (psi)Output Pressure Read
on the Manometer at the
Front Axle in kPa (psi)
500 (73)500 (73)
N/B, H/B0.3/304 500 (653) 3 450 ± 200(500 ± 29)
10 000 (1,450)5 100 ± 300(740 ± 44)
500 (73)500 (73)
WAGON0.3/405 500 (798)4 450 ± 200(645 ± 29)
10 000 (1,450)5 800 ± 300(841 ± 44)
Important : If the pressure exceeds 10 000 kPa (1,450
psi), the pressure reading on the rear gauge will not be ac-
curate.5. Remove the gauges from the tested brake circuit
and repeat the test on the remaining circuit.