You Are At: AllSands Home > Howto > Cooling system flushing
Every six months the cooling system in your automobile should be checked and flushed. Although most people believe that antifreeze should only be added to the cooling system when the colder months begin, antifreeze not only lowers the freezing point of the water in your radiator, it also raises the boiling point of water. Because of this and to keep your automobile in tip top shape during all seasons of the year, your cooling system should be flushed both in winter and summer.
Begin checking your system by removing the radiator cap and looking inside. If the water appears dirty or rusty you should pour in a can of cooling system cleaner. After you have done this you will need to operate your car according to the instructions on the can. To flush the system after using the cleaner or in cases where the water is only mildly dirty you should begin by removing the flushing T cap and attach a hose adapter. Then connect a garden hose to at the adapter. If you car does not have a flushing T you can purchase a flushing T kit at any auto parts store. You will need to install the T to your automobile according to the instructions with the kit. In a case where your radiator tubes are vertical, simply remove the radiator cap and install the water deflector nozzle in the cap neck. When the radiator tubes are horizontal, you will need to disconnect the upper radiator hose at the engine and then aim the end away from the engine.
Next you will need to start the engine of your automobile and turn the heater on, setting it to the hottest temperature. Start the water to the water hose and watch the water coming out of the deflector or upper hose until runs clear for at least two minutes. Then turn off your heater, the engine and last of all, the water. Take the deflector off your radiator or reconnect the upper radiator hose. When this is complete, depending on your cars setup, you will either need to open the radiator petcock, remove the drain plug, or disconnect the lower radiator hose. Allow all the water to drain and then tighten the petcock or refit your drain plug or hose which ever is the case.
Each time you add antifreeze to your automobile you should use an undiluted amount that is equal to between 50 and 70 percent of the capacity of your cooling system. If you are unsure of the capacity of the cooling system on your automobile, check your owners manual to learn the amount to use. If your radiator has been properly drained the antifreeze will mix with the water remaining in the system. In most cases a radiator will not hold all the antifreeze that is called for so you will need to see if your automobile has a reservoir and add any remaining antifreeze in it. When you have no reservoir in your automobile you will need to run the engine with the cap off the T. Turn your heater on and set the temperature to hot while doing this. The fluid will begin to dribble out and you should add antifreeze to the radiator until the needed amount has been added. Stop the engine and replace the cap on the T. Then refit your radiator cap.