Occasionally, a Volkswagen Beetle may overheat. If this is a common occurrence, it may mean that the car's cooling system needs to be refilled. However, you can't refill the cooling system by just pouring in new coolant, as this will trap air bubbles in the system. You need to get the air out of a Volkswagen Beetle's cooling system to stop the engine from overheating and successfully refill the coolant reservoirs.
Pour 1 gallon of coolant into the bucket. Mix with 1 gallon of clean water. Empty the mixture of coolant and water into the empty water jugs.
Plug the air compressor into a power source. Connect one end of the vacuum assist tool to the air compressor.
Rub petroleum jelly on the cone-shaped plug of the vacuum assist tool. Insert the coated plug into the Volkswagen Beetle's coolant reservoir. The petroleum jelly helps seal the edges of the plug to prevent any air from escaping or entering the reservoir.
Turn on the compressor and allow the vacuum assist tool to suction the coolant system. Watch the vacuum assist tool's gauge to ensure that the pressure remains at 2 atmospheres. This will get any trapped air out of the Volkswagen Beetle's cooling system.
Insert the filter end of the vacuum assist tool into the first jug of water and coolant. Open the vacuum plug to allow the coolant mixture to pour into the reservoir. When the jug is empty, restore the vacuum plug and insert the filter end of the tool into the second jug. Allow this jug to empty into the reservoir, too. The cooling system now has a fresh mixture of coolant without any trapped air bubbles.