GM Service Manual Online
For 1990-2009 cars only

NOTICE: When adding coolant, it is important that you use GM Goodwrench DEX-COOL® or HAVOLINE® DEX-COOL® coolant. If Coolant other than DEX-COOL® or HAVOLINE® DEX-COOL® is added to the system the engine coolant will require change sooner; at 50 000 km (30,000 mi) or 24 months.

A see-through plastic reservoir connects to the radiator with a vent hose.

During vehicle use, the coolant heats and expands. The portion of the fluid displaced by this expansion flows from the radiator into the coolant recovery reservoir.

When the vehicle is stopped, and the coolant cools and contracts, vacuum returns the displaced coolant back into the radiator. This keeps the desired level of coolant in the radiator at all times, resulting in increased cooling efficiency.

Maintain the coolant level between ADD and FULL marks on the recovery reservoir. These marks are about one liter (one quart) apart. Use a 50/50 mixture of ethylene glycol antifreeze and clean, drinkable water to keep the system at the FULL mark when the engine is hot.