Subaru 2002 Impreza Service Manual page 335

BRAKE BOOSTER
Brakes
4. Brake Booster
The brake booster is a tandem type that uses two diaphragms. This design provides high brake
boosting effects in spite of a reduced diameter.
(1) Push rod
(2) Return spring
(3) Reaction disc
(4) Key
(5) Filter
(6) Silencer
(7) Operating rod
(8) Poppet valve
B R-9
NF0243
(9) Valve body
(1 0) Plunger valve
(1 1 ) Diaphragm plate
(1 2) Valve return spring