4.8L, 5.3L, 6.0L, 8.1L & 6.6L

CAUTION: DO NOT remove radiator cap when radiator is warm. Removing cap immediately lowers boiling point of coolant and could cause a violent overflow, resulting in large coolant loss and personal injury.

Fill cooling system through surge tank opening. Use a pre-mix of 50/50 DEX-COOL^® engine coolant and water. Add solution until level is slightly above surge tank split line. Start engine and idle for one minute. Loosely install surge tank cap. DO NOT allow engine to build up pressure. Cycle engine RPM from idle to 3000 RPM in 30 second intervals until coolant reaches 210°F (99°C) and thermostat opens. Shut engine off. Carefully remove surge cap. Start engine and idle for about one minute. Fill surge tank to 1/2" above COLD FULL mark on surge tank. Install cap on surge tank. Again, cycle engine RPM between idle and 3000 RPM in 30 second intervals. Shut engine off and check coolant level once again. Wash away any excess coolant from engine compartment.