Cooling System Flush & Coolant Replacement – Getting in Gear with Car Maintenance

In this post in our series on Getting in Gear with Car Maintenance, we are going to take a look at the one of the best ways to help your car keep its cool – the cooling system flush. The best way to understand the importance of a cooling system flush is to start by looking at the role of coolant.

The main job of coolant, or antifreeze, is to transfer excess heat from the vehicle engine to the radiator. The coolant absorbs the heat and redirects it to the radiator where it is evacuated into the air. It may also be directed through the heat exchanger to heat the passenger area. Coolant is comprised of a 50/50 ratio mixture of ethylene or propylene glycol and water. Though water alone could do the job of transferring heat, it is not used alone because it would be too corrosive to the engine.

What a cooling system flush does for your vehicle

The beneficial elements found in coolant breakdown over time, which leaves the engine and radiator vulnerable to corrosion.  Eventually rust deposits can accumulate and clog the cooling system and radiator. The clogs lead to overheating, which is the most common cause of engine damage and breakdowns. A coolant flush and fill will prevent these deposits and overheating.  Ultimately, getting a coolant flush and keeping the coolant fresh is much less trouble and expensive than repairing a heater core or radiator, or head gasket.

What happens during cooling system flush service?

Your auto service professional will:

• Thoroughly inspect the coolant/antifreeze system
• Repair and/or replace any components as necessary
• Replace old coolant/antifreeze with new fluid 

Why are coolant flushes important to your vehicle?

Because it functions in a hot and hostile environment, coolant is subject to rapid break down. Once the coolant’s rust inhibitors become depleted, corrosion may occur in the confined passages in the engine and radiator. Ultimately some corrosion will take place, even with rust inhibitors. The engine block is the main source of rust in a car’s cooling system. Particles of rust will clog radiator and heater passages, causing your engine to overheat. If coolant is not regularly monitored, the rust inhibitors stop working, and the cooling system rusts from the inside out. 

How often are coolant flushes necessary?

The typical time frame for having a coolant flush is two years or 30,000 miles. See your owner’s manual for your vehicle manufacturer’s recommendations.