Mazda 323 1988 Workshop Manual page 761

POWER BRAKE UNIT -i 1
'edal-depr
force 9a
Intake manifold
\
au1 1x-03
1
POWER BRAKE UNIT
ON-VEHICLE INSPECTION
Method Using a Tester
Connect a pressure gauge, vacuum gauge and pedal
depression force gauge as shown in the figure. Af-
ter bleeding the air from the pressure gauge, con-
duct the test as described in the 3 steps below.
Note
Use commercially available gauges and pecl-
al depression force gauge.
Checking for Vacuum Loss at Un-loaded Con-
ditlon
1. Start the engine.
2. Stop the engine when the vacuum gauge reading
reaches 500
m-Hg (19.7 in-Hg).
3. Observe the vacuum gauge for 15 seconds. If the
gauge shows 475-500
mm-Hg (18.7-19.7 in-
Hg),
the unit is serviceable.
Checking for Vacuum Loss at Loaded Condition
1. Start the engine.
2. Depress the brake pedal with a force of
196 N (20
kg, 44 lb).
3. With the brake pedal depressed, stop the engine
when the vacuum gauge reading reaches 500
mm-Hg (19.7 In-Hg).
4. Observe the vacuum gauge for 15 seconds. If the
gauge shows
475-500 mm-Hg (18.7-19.7 in-
Hg),
the unit is serviceable.
Checking for Hydraulic Pressure
1. If with the engine stopped (when the vacuum is
0 mm-Hg),
the relationship between the pedal
force and fluid pressure is within the standard val-
ue range, the unit is serviceable.
Pedal force
Fluid pressure
196 N (20 kg, 44 lb) j 1,373 kPa (14 kg/cm*, 199 psi) min
11-19