Refresh a Car’s Cooling System with a Radiator Flush

By design, a car’s engine operates within a specified temperature. If the engine runs too cool, emissions and fuel economy suffer. If it runs too hot, engine parts begin to deteriorate and seize up.

Normal engine operating temperatures are in the range of 190 to 220 degrees F. (88 to 150 degrees C.). The cooling system maintains the engine operating temperature within this range–when everything is properly functioning.

The Cooling System

A typical gasoline engine cooling system consists of the radiator, water pump, thermostat, radiator hoses, and water ports (water-jackets). When all the components are internally clean and working, life is lovely. However, when the buildup of rust and gunk accumulate inside the system, its cooling capacity begins to deteriorate. The antifreeze in the cooling system works to prevent this buildup.

The Anti-Freeze

The antifreeze, or coolant, has a few different jobs. Yes, it does raise the boiling point and lower the freeze-point of regular water alone. But it also serves as a lubricant and corrosion inhibitor.

While ethylene glycol coolant lasts forever, the additional additives that help protect the engine wear out over time. As the additives breakdown, corrosion and slimy gunk begin to accumulate in the engine block and radiator. Therefore, it’s a good idea to drain and flush the cooling system every two years.

Simply draining the contents of the radiator, and refilling with fresh water and coolant mix, leaves a lot old coolant in the engine block and hoses. Giving the system a good flush, will evacuate a large majority of the old stuff, and give the car a fresh charge of coolant.

Drive through oil-change businesses and auto garages charge as much as $150 dollars or more to perform a radiator flush, according to costhelper.com. You can do this job yourself for much less than that. The only equipment required includes the follow:

• Drain pan for catching the waste coolant
• 1 to 2 gallon bottles of coolant–as recommended by the vehicle manufacturer
• 1 to 2 gallons of distilled water–equal to the amount of coolant required
• Pliers
• Regular Screwdriver
• Sealable container for transporting the waste coolant to the proper disposal or recycle center

Flushing the Radiator

Park the car on a concrete slab or driveway. Positioning the car on a hard surface not only provides an adequate work environment but will help to contain a coolant spill if it occurs. Do not allow the waste coolant to spill on the ground, or remain in an open container. Not only is the coolant bad for the environment, its sweet smell, and taste, is appealing to pets. It takes only a small amount to be fatal for a child or animal.

Remove the radiator cap and set it aside. Open the drain-cock at the bottom of the radiator–pliers may be necessary. Allow the coolant to drain into the pan until the radiator is empty. Close the drain-cock and refill the radiator with plain water until the radiator is full. Replace the radiator cap and start the car engine. Allow the engine to idle for 10 to 15-minutes and turn it off. Repeat the drain and re-fill step again, allowing the engine to cool down before opening the drain-cock. Catch the second batch of wastewater and coolant in the drain pan.

Perform the third flush with fresh water. Depending on the amount of gunk in the cooling system, it may take 2 or 3 flushes before somewhat clearer water drains from the valve. Once satisfied the system is clean, close the drain cock and mix the coolant-water mixture. A 50-percent ratio of coolant to water is ideal. Any amount more than the 60-percent coolant, the boiling point of the coolant begins to drop rapidly. This is one of those times when more, is NOT better.

Mix the coolant-water cocktail in a clean bucket. Pour the mixture into the radiator until the coolant level reaches the bottom of the fill-neck on the radiator. With the radiator full, fill the overflow bottle to the fill-line.

Leave the radiator cap off and start the engine for a few minutes. The coolant level in the radiator will drop, pulling in excess coolant from the overfill tank. Shut the engine down and top off the radiator and overfill tank a second time.

Install the new radiator cap and take the car for a drive. Upon return, and after the engine has had time to cool down, check the coolant level one more time. Make any fluid level adjustments as needed. The radiator flush is complete. Pat yourself on the back for properly maintaining your car, and saving a handful of dollars.