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68-1 2
1977 PONTIAC SERVICE MANUAL
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NOTE: Never open plastic cover when taking readings.
Evaporation of water from the fluid sample being tested
can iffect the reading.
READING
Fig.
68-
1 4
Reading Refractometer
Point the instrument toward any light source and look
into eyepiece (Fig. 6B-14). The anti-freeze protection reading
is at the point where the dividing line between light and dark
(edge of the shadow) crosses the scale; anti-freeze on right
hand scale, battery charge on left.
NOTE: The Tester temperature scale is reversed from
a standard thermometer scale; below zero readings are
on upper half of scale (Fig. 6B-14). Readings on lower
half of scale (above zero readings) indicate solutions
without enough anti-freeze concentration to provide
adequate rust protection.
A little experience will enable you to obtain quickly the
best contrast between the light and dark portions of the field
of view. Tilt the instrument toward the light source until best
results are obtained. If the "edge of the shadow"is not sharp,
the measuring surfaces were not sufficiently well cleaned or
dried. Wipe dry as explained above and make new test.
THERMOSTAT
REMOVE A N D INSTALL
1. Drain radiator level to below thermostat and remove
water outlet assembly.
2. Remove thermostat. Unless obviously defective, test
thermostat as follows before replacing with new one:
a. Immerse unit and thermometer in container of 50/50
glycoVwater over a heater. While heating water, do not rest
either the thermometer or thermostat on bottom of container
as this will cause them to be at a higher temperature than the
water.
b. Agitate water to insure uniform temperature of water,
thermostat and thermometer.
A new thermostat (195" [91°C.]) valve should start to
open (.002" [9l0C.]) at a temperature of 192°F. (89°C.) to
1'98°F. (92°C.) and should be fully open (5/16" or more) at
a temperature not in excess of 222°F. (106°C.).
A used thermostat can be about 10°F. (7°C.) above or
below this setting (185"
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205") (85"
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96°C.) without adverse
effect and should not be replaced. If thermostat does not
operate at specified temperatures, it should be replaced as it
cannot be adjusted.
3. Clean gasket surfaces on housing and intake manifold.
4. Install thermostat with pellet or cartridge projecting
down into water passage.
5. Using new gasket, install water outlet fitting. Tighten
bolts to 30 Ib. ft.
6. Refill radiator to approximately 3" below filler neck
for all models.
WATER PUMP
IMPORTANT: If a water pump is overhauled or
replaced, be sure to fill the cooling system before starting
the engine. Operating the pump in a dry condition for
only a few seconds can cause seal damage and early
failure.
V 6 A N D V 8
Replace
1. Disconnect battery.
2. Drain radiator.
3. Loosen generator and other accessories at adjusting
straps and remove fan belts from fan pulley.
4. Remove fan and pulley.
5. Remove any accessory brackets that might interfere
with pump removal.
6. Remove heater hose and radiator hose at pump.
7. Remove water pump retaining bolts and remove
pump.
8. Install pump by reversing above steps.
9. Tighten water pump attaching bolts to 15 lb. ft.
torque.
10. Adjust belt for proper tension on chart at end of this
section.
Remove
1. Drain cooling system and remove water inlet and
heater hoses.
2. Remove all fan and accessory drive belts.
3. Remove fan and pump pulley.
4. Remove water pump to cylinder block attaching bolts
and remove pump from engine.
Install
1. Clean gasket surfaces and install new gaskets.
2. Install pump and attaching bolts. Coat threaded area
of bolts with part
#
1052080 sealer or equivalent. Tighten to
20 Ib. ft. torque.
3. Replace fan and pump pulley.
4. Install all fan and accessory drive belts.
5. Install water inlet and heater hoses on water pump.
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