Pontiac FIREBIRD 1972 Service Manual page 448

SECTION 5 B
BENDIX POWER BRAKE
SINGLE DIAPHRAGM
The following caution applies to one or more steps in the assembly proce-
dure of components in this portion of the manual as indicated at appropri-
ate locations by the terminology "See Caution on page 1 of this Section".
CAUTI 0 N: THIS FASTENER IS A N IMPOR TA NT A TTA CHING
PART IN THAT IT COULD AFFECT THE PERFORMANCE OF
VITAL COMPONENTS AND SYSTEMS, AND/OR COULD RE-
SULT IN MAJOR REPAIR EXPENSE. IT MUST BE REPLACED
WITH ONE OF THE SAME PART NUMBER OR WITH A N
EQUIVALENT PART IF REPLACEMENT BECOMES NECES-
SAR Y. DO NOT USEA REPLACEMENTPAR T OFLESSER QUAL-
ITY OR SUBSTITUTE DESIGN. TORQUE VALUES MUST BE
USED AS SPECIFIED DURING REASSEMBLY TO ASSURE
PROPER RETENTION OF THIS PART.
CONTENTS OF THIS SECTION
..........................................................
General Description
..............................................
5B-3 Overhaul Unit 5B-7
......................................
Design
...................................................................
5B-3 Disassemble Power Unit 5B-7
..............................
Principles of Operation
............................................
5B-5 Disassemble Master Cylinder 5B-8
......................................
Released Position
................................................
5B-5 Inspection and Cleaning 5B-9
................................
Applying Position
................................................
5B-5 Assemble Master Cylinder 5B- 10
....................................
Holding Position
..................................................
5B-6 Assemble Power Piston 5B-10
......................................
Checks and Adjustments
........................................
5B-7 Push Rod Adjustment 5B-11
Minor Repairs
........................................................
5B-7
TROUBLE DIAGNOSIS AND TESTING
SYSTEM TESTS
Road test the brakes by making a brake application at neutral, apply brakes several times to deplete all vacuum
about 40 mph to determine if the vehicle stops evenly and reserve in the system. Depress brake pedal, hold light-foot
quickly. If the pedal has a spongy feel when applying the pressure on the pedal, and start the engine. If the vacuum
brakes, air may be present in the hydraulic system and system is operating, the pedal will tend to fall away under
bleeding of brakes may be required. foot pressure, and less pressure will be required to hold
pedal in applied position. If no action is felt, the vacuum
When the engine is stopped and the transmission is in system is not functioning.