Chevrolet CHEVY VAN G10 SERIES Service Manual page 170

General D e s c rip tio n .................................................................. 6K -1
M aintenance and A d ju s tm e n ts ...............................................6 K -2
C oolant Level ....................................................................... 6K -2
C oolant System C h e c k s ......................................................6K -2
Periodic M a in te n an ce...........................................................6K -2
Cleaning ............................................................................ 6 K -2
Reverse F lu s h in g ............................................................. 6K -3
R a d ia to r ....................................................................... 6K -3
Cylinder Block and Cylinder Head . •....................6K -3
All Chevrolet trucks have pressure ty p e engine cooling
system s w ith therm ostatic control o f coolant circulation. The
cooling system is sealed b y a pressure ty pe radiator filler cap.
The pressure type radiator filler cap (Fig. 1) is designed to
operate the cooling system at higher than atm ospheric
Fig. 1—Radiator Pressure Cap
Fig. 2 —W ater Pum p—Typical L 6
SECTION 6K
ENGINE COOLING
INDEX
P age
GENERAL DESCRIPTION
H eater Core ................................................................6K -3
Fan Belt A djustm ent ................................................................6K -3
R adiator Cap .............................................................................. 6K -3
T h e rm o s ta t................................................................................... 6K -3
R e p la c e m e n t..........................................................................6K -3
Therm ostatic Fan C lutch R eplacem ent ..............................6K -4
Water P u m p .................................................................................6K -5
Removal ............................................................................ . . 6K -5
Installation ............................................................................ 6K -5
pressure. The higher pressure raises th e boiling po in t o f the
coolant w hich increases the efficiency o f th e radiator.
The radiator filler cap contains a pressure relief valve and a
vacuum relief valve. The pressure relief valve is held against its
seat by a spring w hich w hen com pressed, allows excessive
pressure to be relieved o u t th e radiator overflow.
The vacuum valve is also held against its seat b y a spring
w hich w hen com pressed, opens th e valve relieving the vacuum
created w hen th e system cools off.
The cooling system 's w ater pum p is o f th e centrifugal vane
im peller typ e (Figs. 2 and 3). The bearings are perm anently
lubricated during m anufacture and are sealed to prevent the
loss o f lubricant or th e e n try o f d irt and w ater. The pump
requires no care oth er th a n to m ake certain the air vent at the
to p o f th e housing and th e drain holes in th e b o tto m do not
becom e plugged w ith dirt or grease.
Fig. 3 —Water Pum p—Typical V 8
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