The cost of an antifreeze flush is much less than a heater core or radiator repair.
Automotive cooling system
Winter is quickly approaching and it's time to get our cars ready for it. One of the most common services is the antifreeze flush, or coolant flush. There was a time when the system was just drained at the radiator and then topped off with new antifreeze. Now most repair shops have machines that flush the system. There are pros and cons to both and I'll fill you in on them.
The heater core is a box inside the dash that looks like the radiator only much smaller. The primary function is to bring warm air into the car by passing the hot fluid through it.
Both the radiator and the heater core are made of metal. The antifreeze is diluted with water. Eventually, the water will help creathe corrosion inside the radiator and/or the heater core. If the corrosion builds up, it blocks the flow which can cause engine overheating or no heat inside the car. Very bad for frosted windshields. There is also the possibility of a leak at either one of those. A radiator leak sucks, a heater core leak stinks...literally. All of this worn out, smelly fluid in your heater core will leak out inside your car on the passenger side floorboard.
The antifreeze is pushed all around the engine by the water pump which is a belt driven pump. (Checking belts is also a good idea.). As the coolant flows around the engine, it carries the heat away to the radiator or heater core.
Keeping it cool
The thermostat is a temperature controlled valve that helps direct the fluid once the engine is warmed up. The radiator allows the hot antifreeze to be cooled by the incoming air passing through heat dispersing fins. Then the cooled antifreeze returns to the engine to begin the process again.
Repairing the cooling system
The repair cost for a radiator is usually $250 and up depending on the vehicle. A heater core repair is usually $600 and up because it's located deep inside the dash and requires a lot of work to replace.
Water pump failure is usually at the gasket that seals it or the internal propeller fins deteriorating. This can also run about $250 and up.
A cooling system drain and fill consists of opening up a valve at the bottom of the radiator and letting what sits in it, run out. Then the valve is closed, the system filled and the vehicle started to push out the air and top off the fluid. Pros are- it's quick and easy. Cons are-it's not very thorough, fluid sitting in the heater core and engine doesn't come out and it just gets mixed with the new fluid.
A cooling system flush consists of hooking up hoses in line to the cooling system and using a machine to push fluid through the entire cooling system. Pros are-it's very thorough and will often pull out the beginnings of corrosion formation. Cons are- sometimes when the corrosion comes out it leaves small pinholes that quickly turn to leaks, so if you didn't have a leak before, you might now.
Ultimately, if you flush the cooling system of your vehicle at regular intervals, every 30 or 60,000 miles, you shouldn't have a problem. A lot of manufacturers have new and improved antifreeze that they claim may not need flushed until 100,00 miles. The problems I have seen there are that the long lasting properties in the system can actually cause a problem instead of corrosion.
Flushing the antifreeze is a maintenance thing, if you do it, it will prolong the life of other components. If you don't do it, it's only a matter of time.