BRAKES 5-44
requ ired with the conventional (nonpower) hydraulic brake
fir e w all and connected to the brake pedal through an
system . The unit is mounted on the engine side of the
au xilia ry le v e r and rod.
MAINTENANCE AND ADJUSTMENT
Inspection
1. Check vacuum line and vacuum line connections as
w e ll as vacuum check v a lv e in front shell of pow er
unit fo r p ossib le vacuum loss.
2. Inspect a ll hydraulic lin es and connections at the
wheel cylin d ers and main cylin d er fo r possible
hydraulic leaks.
3. Check brake a ssem b lies fo r scored drums, grea se o r
brake fluid on linings, worn o r glazed linings, and
make n ecessa ry adjustments.
4. Check the brake fluid le v e l in the hydraulic r e s e r
v o ir . The r e s e r v o ir should be fille d to within 1/2"
o f the top o f the f i l l e r cap opening. Inspect the
r e s e r v o ir c o v e r fo r flu id leaks at gasket.
5. Check fo r loose mounting bolts at main cylin d er and
at pow er section.
7. Check brake pedal fo r bending and m isalignm ent
between pedal and push rod.
6. Check a ir clea n er f ilt e r located in the p ow er piston
ex te n s io n --re p la c e f ilt e r i f n ecessary.
Lubrication
The M a s te r-V a c p ow er brake unit is lubricated at a s
sem bly and needs no fu rth er lubrication other than m ain
taining norm al r e s e r v o ir fluid le v e l.
The r e s e r v o ir
should be fille d as d escrib ed in this section, using only
recom m ended brake fluid.
Bleeding Instructions
The pow er system m ay be bled manually o r with a
p ressu re b leed er as outlined in this section.
Use only recom m ended brake fluid. Do not use pow er
a ssist while bleeding. The engine should not be running
and the vacuum r e s e r v e should be reduced to zero , by
applying the brake s e v e r a l tim es b efo re starting the
bleeding procedu re.
A ir Cleaner Service
The a ir clea n er filt e r used with the p ow er brake unit
should be cleaned at lea st tw ice a yea r. To clean, r e
m ove a ir clean er elem ent and wash thoroughly in cleaning
s o lven t— allow elem ent to dry b efo re rein stallin g.
VACUUM POWER BRAKE UNITS
( 4 0 - 5 0 - 6 0 SERIES)
GENERAL DESCRIPTION
Vacuum pow er cylin d ers a re used as standard equip
ment o r are available as optional equipment on a ll 40-50-
60 s e r ie s ve h ic le s with hydraulic brakes.
The tandem diaphragm unit is used with sin gle main
cylin d er applications and in crea ses p ressu re to a ll wheel
brakes.
Single diaphragm units are used on veh icles
with the dual brake system . Two units are used on the
veh icle, each one boosting the p ressu re in h alf o f the
sp lit system .
A m anifold check va lve is installed in the vacuum line
running fro m the engine intake m anifold to the front
cham ber o f the booster unit.
F ig u re s 78 to 82 show the vacuum b ooster system and
parts.
See the Overhaul Manual fo r s e r v ic e details.
MAINTENANCE AND ADJUSTMENT
BLEEDING THE SYSTEM
Pressure Bleeding
Stop engine and d estro y vacuum in system b efore
startin g bleeding operations.
1. Check brake fluid in m a ster cylin d er and fill.
2. Open pow er cylin d er b le e d e r scew and allow fluid to
run until c le a r o r fr e e fro m a ir bubbles.
3. B leed a ll wheel cylin d ers until fr e e o f a ir bubbles
starting at the cylin d er n ea rest the p ow er cylin der.
IM P O R T A N T :
DO
N O T
A P P L Y B R A K E S
W H IL E ENGINE IS RUNNING, W IT H PRESSURE
B LE E D E R C O NNECTED OR PO W ER U N IT M A Y
BE DAM AGED.
4. Disconnect p ressu re b leed er.
5. Apply brakes and check a ll lin es fo r leaks.
NOTE:
If fir m pedal is not obtained - - start
engine - - apply brakes ligh tly and reb leed vacu
um pow er brake unit.
M an u al Bleeding
Manual bleeding is s im ila r to p ressu re bleeding except
that the brake fluid is fo rced through the lin es by pumping
the brake pedal. An assistant is req u ired to pump the
brake pedal.
1. Start engine and pump brake pedal th ree tim es o r
until grea test pedal height is obtained--m aintain foot
pedal pressu re.
2. S low ly open b leed er va lve on pow er cylin d er allow ing
pedal to tra v e l only 3/4 strok e. C lose pow er c y l
in der valve.
CHEVROLET TRUCK SERVICE MANUAL
Содержание 10 Series 1970
Страница 1: ......
Страница 38: ...HEATER AND AIR CONDITIONING 1A 8 CHEVROLET TRUCK SERVICE MANUAL...
Страница 57: ...HEATER AND AIR CONDITIONING 1A 27 Fig 35 Compressor M ountings CHEVROLET TRUCK SERVICE MANUAL...
Страница 75: ...HEATER AND AIR CONDITIONING 1A 45 Fig 65 R oof M ounted System W iring Diagram CHEVROLET TRUCK SERVICE MANUAL...
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Страница 101: ...BODY IB 23 s A ADJUSTER SCREW AND LEVER ASSY Fig 5 9 Exploded V iew o f Level Ride Seat CHEVROLET TRUCK SERVICE MANUAL...
Страница 137: ...BODY IB 59 VIEW IN DIRECTION OF ARROW A Fig 137 A u x ilia ry Seat CHEVROLET TRUCK SERVICE MANUAL...
Страница 142: ...CHEVROLET TRUCK SERVICE MANUAL Fig 5 10 30 Series Truck Frame FRAME 2 4...
Страница 145: ...CHEVROLET TRUCK SERVICE MANUAL FRAME 2 7...
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Страница 228: ...REAR SUSPENSION AND DRIVE LINE 4 52 I Fig 88 Forward Rear A xle Assembly Exploded V iew CHEVROLET TRUCK SERVICE MANUAL...
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Страница 383: ...ENGINE FUEL 6M 19 F ig I t Engine Fuel S p ecial Tools CHEVROLET TRUCK SERVICE MANUAL...
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Страница 432: ...Fig 1 C lu tch Linkage Except P 2 0 4 0 Series...
Страница 433: ...CLUTCHES AND TRANSMISSIONS 7 3 Fig 2 C lutch Linkage Step Van P 20 40 Series CHEVROLET TRUCK SERVICE MANUAL...
Страница 506: ...FUEL TANK AND EXHAUST SYSTEMS 8 8 Fig 10 Vent Lines Cab M ounted Tanks CHEVROLET TRUCK SERVICE MANUAL...
Страница 528: ...Fig 31 T yp ica l Power Steering Hose Routings...
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Страница 566: ...ELECTRICAL BODY AND CHASSIS 12 4 Fig 3 Front Lighting Assemblies CHEVROLET TRUCK SERVICE MANUAL...
Страница 567: ...ELECTRICAL BODY AND CHASSIS 12 5 Fig 4 C learance and Id e n tific a tio n Lamps CHEVROLET TRUCK SERVICE MANUAL...
Страница 568: ...ELECTRICAL BODY AND CHASSIS 12 6 Fig 5 Rear Lighting Composite CHEVROLET TRUCK SERVICE MANUAL...
Страница 597: ...ELECTRICAL BODY AND CHASSIS 12 35 Fig 37 Engine Com partm ent CE M E60 CHEVROLET TRUCK SERVICE MANUAL...
Страница 598: ...ELECTRICAL BODY AND CHASSIS 12 36 TO FRAME i f Fig 38 Engine Com partm ent C D 50 CHEVROLET TRUCK SERVICE MANUAL...
Страница 608: ...ELECTRICAL BODY AND CHASSIS 12 46 Fig 48 Instrument Panel C A40 CE CS ME50 Exc 02 CHEVROLET TRUCK SERVICE MANUAL...
Страница 610: ...ELECTRICAL BODY AND CHASSIS 12 48 Fig 50 Instrument Panel CE M E60 03 13 CHEVROLET TRUCK SERVICE MANUAL...
Страница 614: ...ELECTRICAL BODY AND CHASSIS 12 52 Fig 54 Instrument Panel SA40 50 CHEVROLET TRUCK SERVICE MANUAL...
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Страница 649: ...SPECIFICATIONS 9 ENGINE SECTION 6 CHEVROLET TRUCK SERVICE MANUAL...
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