Shake bottle well before use. Allow the cold engine to warm up briefly until the thermostat opens. (Do not use when the engine is hot). Switch off the engine, then pour the contents of the bottle into the cooler or directly into the cooling circuit. For vehicles without a filling opening on the cooler, disconnect the top hose to the cooler and fill in the product there. Allow the engine to warm up for 10 minutes, setting the heating to the highest level. If necessary, top up the missing amount of water.