GMC SIERRA 1994 Manual page 232

3. Open the air
bleed valve
located on the
thermostat
housing.
4. Fill the coolant
surge tank with
the proper mix,
up to the COLD
mark.
While filling the surge tank, watch to see if coolant begins to stream
out the air bleed valve. When coolant begins to stream out, close the
valve.
>.
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5. With the air bleed
valve closed and
the coolant surge
tank pressure cap
off, start the
engine and let it
run until you can
feel the upper
radiator hose
getting hot.
Watch out for the
engine fan(s).
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