Subaru IMPREZA GD 2007 Series Manual page 3253

asieps_tobira_IM_US.book 44 ページ ２０１２年１月１７日 火曜日 午後３時４８分
BRAKE
2. OPERATION CHECK (WITH GAUGE)
CAUTION:
When checking operation, be sure to apply the
parking brake securely.
Check with gauge
Connect the gauge as shown in the figure. After
bleeding air from pressure gauge, perform each
check.
(1) (2)
(3)
(1) Pressure gauge
(2) Vacuum gauge
(3) Adapter hose
(4) Vacuum hose
(5) Pedal force gauge
Air tightness check
1) Start the engine and keep it running until vacu-
um pressure indicates point A of the vacuum gauge
= 66.7 kPa (500 mmHg, 19.69 inHg). Do not de-
press the brake pedal at this time.
(1) (2)
(1) Pressure gauge
(2) Vacuum gauge
Brake Booster
(4) (5)
BR-00082
A
BR-00083
BR-44
2) Stop the engine and check the gauge. If the vac-
uum pressure drop within 15 seconds after stop-
ping the engine is 3.3 kPa (25 mmHg, 0.98 inHg) or
less, the function of brake booster is normal.
If faulty, the cause may be one of the following.
• Check valve malfunction
• Leak from vacuum hose
• Leak from shell joint section or stud bolt welded
section
• Damaged diaphragm
• Leak from valve body seal and bearing section
• Leak from plate and seal assembly section
• Leak from poppet valve assembly section
Loaded air tightness check
1) Start the engine and depress the brake pedal
with a pedal force of 196 N (20 kgf, 44 lbf). Keep the
engine running and keep the pedal pressed until a
vacuum of point B = 66.7 kPa (500 mmHg, 19.69
inHg) is indicated on the vacuum gauge.
(1) (2)
(1) Pressure gauge
(2) Vacuum gauge
(3) Pedal force gauge
(4) Depressed
2) Stop the engine and check the vacuum gauge.
If the vacuum pressure drop within 15 seconds af-
ter stopping the engine is 3.3 kPa (25 mmHg, 0.98
inHg) or less, the function of brake booster is nor-
mal.
If defective, refer to "AIR TIGHTNESS CHECK".
<Ref. to BR-43, INSPECTION, Brake Booster.>
B
(3)
(4)
BR-00084