Opel 1900 1973, Service Manual

Page: 323 / 625

1973 OPEL SERVICE MANUAL
COOLING SYSTEM
CONTENTS
Subject
DESCRIPTION AND OPERATION:
Cooling System and Water Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
DIAGNOSIS: (Not Applicable)
MAINTENANCE AND ADJUSTMENTS:
Checking and Filling Cooling System
. . . . . . . . . . . . . . . . . . . . . . . .
Draining and Flushing Cooling System . . . . . . . . . . . . . . . . . . . . . .
Conditioning the Cooling System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using and Testing Anti-Freeze Solutions . . . . . . . . . . . . . . . . . .
Fan Belt Adjustment or Replacement . . . . . . . . . . . . . . . . . . . . . . . .
Radiator Thermostat Inspection and Test . . . . . . . . . . . . . . . .
MAJOR REPAIR:
Water Pump Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Radiator Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
SPECIFICATIONS:
Cooling System Capacities
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Page No.
DESCRIPTION AND OPERATION
COOLING SYSTEM AND WATER PUMP
The system is of the conventional pressurized
type. A centrifugal pump arranged in timing case
serves to circulate the coolant.
When the thermostat is closed, the coolant will re-
turn to the pump via a by-pass for swift and uniform
warming up of the engine the coolant circulates
through the radiator, only when the engine has
reached normal operating temperature.
The heater system branches off the cooling system
ahead of thermostat in flow direction so that the
heater is in operation before engine has reached full
operating temperature.
MAINTENANCE AND ADJUSTMENTS
Checking and Filling Cooling System
The coolant level should be checked only when the
engine is cold and only enough coolant should
be
added to bring the level halfway between core and
tank top. It is unnecessary and undesirable to remove
the radiator cap and check the coolant level each
time the car stops at a filling station for gasoline or
oil, since the engine is usually hot at such times.
WARNING:
Never remove the radiator cap quickly
when engine is HOT Sudden release of cooling
pressure may cause the coolant to boil and some
of it may be ejected from the radiator neck,
resulting in to persons or damage to the car
finish.
If it is necessary at any time to remove the radiator
cap when engine is hot, rotate the cap counterclock-
wise until first stop is reached. Leave cap in this
position until all pressure in cooling system has been
released, then turn cap past the first stop and remove
it.
Draining and Flushing
Cooling System
The cooling system should be completely drained
and the recommended coolant installed every two (2)
years.
To drain the cooling system, remove radiator cap,
remove lower radiator hose from the lower tank and