Pontiac 1998 Firebird Owner's Manual page 356

150,000 Miles (240 000 km)
0
Drain, flush and refill cooling system (or every 60 months since last service,
whichever occurs first). See "Engine Coolant" in the Index for what to use.
DATE
1
MILEAGE
ACTUAL
I
SERVICED BY:
Inspect hoses. Clean radiator, condenser, pressure cap and neck. Pressure test
I
I
I
the cooling system and pressure cap.
An Emission Control Service.
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