Chevrolet 70 1969 Series, Shop Manual

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6V-53 DIESEL ENGINE 6C-18
A B N O R M A L ENG INE C O O LA N T TEMPERATURES
ABO V E N O RM A L OPERATING TEMPERATURES
INSUFFICIENT HEAT TRANSFER-Check for the following:
1. Scale Deposits in Cooling System—Clean cooling system with a good cooling system
cleaner and flush thoroughly.
2
.
Radiator Core Plugged Preventing Normal Air Flow—Clean outside of radiator core.
3
.
Fan Belt Loose—Tighten fan belt.
4.
Improper Installation—Improper shrouding of fan.
POOR CIRCULATION—Check for the following:
1. Coolant Level too Low—Fill radiator to filler neck.
2
.
Hoses Collapsed or Disintegrated—Replace hoses.
3
.
Thermostat Damaged—Replace thermostat.
4.
Water Pump Impeller Loose on Shaft—Replace impeller or shaft.
5. Inadequate Water Supply on Suction Side of Pump—Caused by:
a. Radiator Clogged—Clean radiator.
b. Combustion Gases in Cooling Water—Replace all head gaskets and inspect cylinder
heads for cracks or injector tube leaking.
c. Air in Cooling System—Caused by:
(1) Air Leak on Suction Side of Water Pump—Replace defective parts.
(
2
)
Thermostat Housing Vent Holes Plugged—Clean.
BELOW N O RM A L
POOR CIRCULATION—Check for the following:
1. Thermostat Inoperative—Replace thermostat.
2
.
Thermostat Seat Damaged—Replace thermostat.
3
.
Thermostat Seal Damaged—Replace seal.
CHEVROLET SERIES 70-60 H EAVY DUTY TRUCK SH O P M A N U A L