GMC 2007 Envoy - Manual (Page 415)

3. Fill the radiator with the proper DEX-COOL ®
coolant mixture, up to the base of the filler
neck. See Engine Coolant on page 405
for more information about the proper coolant
mixture.
4. Then fill the coolant recovery tank to the
FULL COLD mark.
5. Put the cap back on the coolant recovery tank,
but leave the radiator pressure cap off.
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