2003 Mercury Marauder Owner's Manual - Page 191

Maintenance and Specifications To reduce the risk of 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 cap counterclockwise (left) until pressure begins to release. 3. Step back while the pressure releases. 4. When you are sure that all the pressure has been released, use the cloth to turn it counterclockwise and remove the cap. If coolant reservoir is empty, continue with steps 5-9, if coolant reservoir level is only slightly low (coolant still in reservoir), continue to steps 8 and 9 only. 5. Remove coolant bleed plug from the coolant bypass tube using 1/4 inch square drive. 6. Add coolant/water mixture through the bypass tube opening until full at bypass opening. 191