2000 Mercury Mystique Owner's Manual - Page 176
2000 Mercury Mystique Manual
Page 176 highlights
Maintenance and care To avoid personal injury, make sure the engine is cool before unscrewing the coolant pressure relief cap. The cooling system is under pressure; steam and hot liquid can come out forcefully when the cap is loosened slightly. 1. Before you begin, turn the engine off and let it cool. 2. When the engine is cool, wrap a thick cloth around the coolant pressure relief cap on the coolant reservoir (an opaque plastic bottle). Slowly turn the cap counterclockwise (left) until the pressure begins to release. 3. Step back while the pressure releases (you may hear a hissing sound). 4. When you are sure that all the pressure has been released from the cooling system, use the cloth to turn the cap counterclockwise and remove it. 5. Fill the coolant reservoir slowly with the proper coolant mixture (see above) to within the "cold full" or the "cold fill range" level on the reservoir. 6. Replace the cap. Turn until tightly installed. (Cap must be tightly installed to prevent coolant loss.) MI N M A X 176