Subaru 2001 FORESTER Service Manual page 44

¼ Checking with gauges
Connect gauges as shown in Figure. After bleed-
ing air from pressure gauges, proceed to each
check.
(1) Pressure gauge
(2) Vacuum gauge
(3) Adapter hose
(4) Vacuum hose
(5) Pedal force gauge
¼ Air tightness check
1) Start engine and keep it running until a vacuum
of 66.7 kPa (500 mmHg, 19.69 inHg) = point A is
indicated on vacuum gauge. Do not depress brake
pedal.
(1) Pressure gauge
(2) Vacuum gauge
2) Stop engine and watch the gauge. If the
vacuum drop range is less than 3.3 kPa (25
mmHg, 0.98 inHg) within 15 seconds after stop-
ping engine, brake booster is functioning properly.
If defective, the cause may be one of those listed
below.
¼ Check valve malfunction
¼ Leak from vacuum hose
¼ Leak from the shell jointed portion or stud bolt
welded portion
¼ Damaged diaphragm
¼ Leak from valve body seal and bearing portion
¼ Leak from plate and seal assembly portion
¼ Leak from poppet valve assembly portion
BRAKE BOOSTER
¼ Loaded air tightness check
1) Start engine and depress brake pedal with
pedal force of 196 N (20 kg, 44 lb). Keep engine
running until a vacuum of 66.7 kPa (500 mmHg,
19.69 inHg) = point B is indicated on vacuum
gauge while the pedal is still depressed.
S4M0467A
(1)
(2)
(3)
(4)
2) Stop engine and watch vacuum gauge.
If the vacuum drop range is less than 3.3 kPa (25
mmHg, 0.98 inHg) within 15 seconds after stop-
ping engine, brake booster is functioning properly.
If defective, refer to "AIR TIGHTNESS CHECK".
<Ref. to BR-42 INSPECTION, Brake Booster.>
¼ Lack of boosting action check
Turn off engine, and set the vacuum gauge read-
ing at "0". Then, check the fluid pressure when
brake pedal is depressed. The pressure must be
greater than the standard value listed.
Brake pedal
force
Fluid
S4M0468A
pressure
¼ Boosting action check
Set the vacuum gauge reading at 66.7 kPa (500
mmHg, 19.69 inHg) by running engine. Then,
check the fluid pressure when brake pedal is
depressed. The pressure must be greater than the
standard value listed.
Brake pedal
force
Fluid
pressure
BR-43
Pressure gauge
Vacuum gauge
Pedal force gauge
Depress
147 N
(15 kgf, 33 lb)
588 kPa
2
(6 kg/cm , 85 psi)
147 N
(15 kgf, 33 lb)
5,394 kPa
2
(55 kg/cm , 782 psi)
Brake
S4M0469A
294 N
(30 kgf, 66 lb)
1,667 kPa
2
(17 kg/cm , 242 psi)
294 N
(30 kgf, 66 lb)
10,003 kPa
2
(102 kg/cm , 1,450
psi)