5 - 6 0 BRAKES
POWER BRAKES
INDEX
General Description.......................................................................... 5-60
Theory of Operation......................................................................... 5-60
Maintenance and Adjustments...................................................... 5-66
Air Cleaner Service......................................................................... 5-66
Component Part Replacement....................................................... 5-66
Power Brake Unit............................................................................ 5-66
GENERAL DESCRIPTION
The Power brake Unit is a self-contained hydraulic and
vacuum unit, utilizing manifold vacuum and atmospheric
pressure for its power.
This unit permits the use of a low brake pedal as well as
less pedal effort than is required with the conventional
(nonpower) hydraulic brake system. The unit is mounted
on the engine side of the dash panel and directly
connected to the brake pedal.
THEORY OF OPERATION
A power brake is used with the brake system to reduce
the braking effort required by the driver. A combined
vacuum and hydraulic unit, which utilizes engine
manifold vacuum and atmospheric pressure, is used to
provide power assisted application of vehicle brakes.
The unit is used in conjunction with a conventional
brake system. From the master cylinder connection
outward to the wheel units, there is no other change in
the brake system.
In addition to the master cylinder connections, the unit
requires a vacuum connection to the engine intake
manifold (through a vacuum check valve) and a
mechanical connection to the brake pedal. The unit is
self-contained.
The vacuum power unit contains the power piston
assembly, which houses the control valve and reaction
mechanism, and the power piston return spring. The
control valve is composed of the air valve (valve
plunger), the floating control valve assembly, and the
push rod. The reaction mechanism consists of a
hydraulic piston reaction plate and a series of levers. An
air filter, air silencer, and filter retainer are assembled
around the valve operating rod filling the cavity inside
the hub of the power piston. The push rod or valve
operating rod, which operates the air valve, projects out
of the end of the power unit housing through a rubber
dust guard. A vacuum check valve assembly is mounted
in the front housing assembly for connection to the
vacuum source.
LIGHT DUTY TRUCK SERVICE MANUAL
Summary of Contents for Light Duty Truck 1973
Page 1: ......
Page 4: ......
Page 6: ......
Page 53: ...HEATER AND AIR CONDITIONING 1A 27 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 115: ...LIGHT DUTY TRUCK SERVICE M A N U A L HEATER AND AIR CONDITIONING 1A 89...
Page 123: ...BODY 1B 3 Fig 6 Typical 06 Van LIGHT DUTY TRUCK SERVICE MANUAL...
Page 149: ...BODY 1B 29 Fig 84 Body Mounting 06 Fig 85 Body Mounting 14 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 171: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 2 Frame Horizontal Checking Typical FRAME 2 3...
Page 173: ...LIGHT DUTY TRUCK SERVICE M A N U A L Fig 4 10 30 Series Truck Frame FRAME 2 5...
Page 174: ...2 6 FRAME LIGHT DUTY TRUCK SERVICE MANUAL Fig 5 Underbody Reference Points G Van...
Page 185: ...FRONT SUSPENSION 3 11 Fig 16 Toe out on Turns LIGHT DUTY TRUCK SERVICE MANUAL...
Page 224: ......
Page 266: ......
Page 351: ...ENGINE 6 15 Fig ID Sectional View of Eight Cylinder Engine LIGHT DUTY TRUCK SERVICE MANUAL...
Page 375: ...EN G IN E 6 39 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 376: ...6 4 0 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 377: ...ENG IN E 6 41 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 378: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 37L K Series Engine Front Mount 6 42 ENG INE...
Page 400: ...6 6 4 ENG INE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 401: ...ENG IN E 6 65 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 402: ...6 6 6 ENGINE LIGHT DUTY TRUCK SERVICE MANUAL...
Page 403: ...E NG IN E 6 67 Fig 36V C Series Engine Mounts LIGHT DUTY TRUCK SERVICE MANUAL...
Page 410: ......
Page 423: ...EN G IN E C OOLING 6K 13 Fig 16 Overheating Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 424: ...6 K 1 4 ENG INE COOLING Fig 17 Coolant Loss Chart LIGHT DUTY TRUCK SERVICE MANUAL...
Page 456: ...6M 32 ENGINE FUEL Fig K15 Accelerator Controls G Van L 6 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 492: ......
Page 512: ...Fig 18e Vacuum Advance Diagram V8 Engine...
Page 516: ...6 T 2 4 E M IS S IO N CONTROL SYSTEMS LIGHT DUTY TRUCK SERVICE MANUAL...
Page 528: ......
Page 590: ......
Page 593: ...CLUTCHES MANUAL TRANSMISSIONS 7M 3 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 598: ...7M 8 CLUTCHES MANUAL TRANSMISSIONS LIGHT DUTY TRUCK SERVICE MANUAL...
Page 642: ......
Page 654: ......
Page 743: ...FUEL TANKS AND EXHAUST 8 13 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 744: ...8 14 FUEL TANKS AND EXHAUST LIGHT DUTY TRUCK SERVICE MANUAL...
Page 760: ...8 30 FUEL TANKS AND EXHAUST Fig 40 Exhaust Pipe P Models LIGHT DUTY TRUCK SERVICE MANUAL...
Page 761: ...FUEL TANKS AND EXHAUST 8 31 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 763: ...FUEL TANKS AND EXHAUST 8 33 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 766: ......
Page 832: ...LIGHT DUTY TRUCK SERVICE MANUAL Fig 106 Power Steering Pump Mounting Typical 9 66 STEERING...
Page 833: ...PUMP ASSEMBLY STEERING GEAR TYPICAL SMALL V8 TYPICAL LARGE V8 STEERING 9 67...
Page 861: ...STEERING 9 95 Fig 134 Power Steering Pump Leakage LIGHT DUTY TRUCK SERVICE MANUAL...
Page 864: ......
Page 876: ......
Page 886: ...11 10 CHASSIS SHEET METAL LIGHT DUTY TRUCK SERVICE MANUAL...
Page 891: ...ELECTRICAL BODY AND CHASSIS 12 5 LIGHT DUTY TRUCK SERVICE MANUAL...
Page 934: ......
Page 942: ......
Page 970: ......
Page 972: ......
Page 974: ......
Page 976: ...V...
Page 978: ......
Page 979: ......