Article > Cooling System

Radiators Keep Everything Cool

By Larry Carley

Today’s coolants last a long time (up to 5 years or 150,000 miles, which ever comes first), but they are not lifetime coolants.
When cooling systems are not maintained, it can cause cooling problems, overheating and radiator failure. Today’s coolants last a long time (up to 5 years or 150,000 miles, which ever comes first), but they are not lifetime coolants. Eventually, the corrosion inhibitors in the antifreeze wear out and allow electrolytic corrosion to attack the system from the inside out.

The most vulnerable components in the cooling system are the radiator and heater core, especially lead soldered copper/brass heat exchangers in older vehicles. Aluminum radiators and heater cores in newer vehicles are better able to withstand the corrosive effects of worn-out coolant, but not forever. Eventually, the metal will be eaten away, creating pinholes that allow the radiator to leak. This type of damage is usually too extensive to risk patching, so replacing the radiator core or the radiator itself is usually necessary.

Many aluminum radiators have plastic end tanks. Plastic won’t rust or corrode, but it can be eroded by sediment circulating in dirty coolant. Sediment can have an abrasive effect that scours away at the soft plastic. Plastic also doesn’t handle severe overheating very well either. Hot steam can literally melt a hole right through an end tank!

The rubber seal between the plastic end tanks and the radiator core can also be a source of trouble. Vibration and thermal expansion/contraction can loosen the seal, causing the radiator to leak. This type of leak can be difficult to repair because the core is clamped to the end tank. Repairing an end tank leak requires special equipment and the services of a radiator repair shop. Cooling system sealer may temporarily plug a small leak, but sooner or later the radiator will have to be repaired or replaced.

Clogging is another problem that can prevent a radiator from cooling properly. Rust and scale in the cooling system can clog up the small passageways in small radiator tubes. Cleaning the cooling system may get rid of most of the contaminants. But a clogged radiator can be very difficult to clean, and usually has to be removed and disassembled for professional cleaning in a hot tank, or replaced.

Repairs at a radiator shop can be time-consuming and expensive, often taking several days and costing hundreds of dollars. That’s why replacement radiators have become so popular. They are cost-competitive with what most radiator shops charge to repair a radiator, and there’s no delay. Just remove the old radiator and replace it with a new one.
Aftermarket replacement radiators are available in a wide variety of materials, designs and sizes. What’s important here is matching (or exceeding) the cooling performance of the original. Some replacement radiators provide improved cooling performance with additional rows of tubes, added thickness and/or a more efficient design.

For some applications, there may be an aluminum or copper/brass radiator available as a replacement option. There’s usually not a huge difference in price, so cooling performance and weight may be the main features to consider. Aluminum is typically lighter while copper has excellent heat transfer characteristics. However, the overall cooling performance of a replacement radiator will vary depending on its design and size.

The width, height and thickness of a new radiator should match that of the old radiator for ease of installation — unless the customer wants a larger radiator for improved cooling performance. The size and location of the hose connections and ATF cooler connections on the radiator (if used) must also be similar to those on the original radiator.

It’s also important to replace the radiator cap along with the radiator. Old radiator caps can leak pressure and cause an engine to overheat. A new thermostat should also be recommended, along with a new upper and lower radiator hose.
Your customer will also need antifreeze and water (distilled or deionized is recommended). A 50/50 mix of antifreeze and water is the standard recommendation for year-round freezing and boilover protection.
  Previous Comments
avatar   Richard   star   5/2/2010   2:14 PM

Yeah try getting a customer to purchase the items for flushing the cooling system out properly. " I flushed the radiatore already" is the typical response. Then when you try to explain how itis done they simply say nah i cant do that. Then when you see them in a few months for the radiator they still dont want to listen about flushing out hte engine block and heater core to protect the new radiator. Its like talking to a wall. They feel it is too costly and even after you recommend the specific antifreeze they simply say give me the cheapest even if it isnt the right one. Too many of todays customers and even the " ive been working on cars my whole life" guys dont want to take the time to do it righ tbecause they know that to get thier warranty covered all they have to do is scream and holler and they get what they want.

avatar   Ed   star   4/27/2010   4:49 PM

"Usually not a huge difference in price," when was the last time you priced a copper/brass optional replacement radiator? They are normally in the $200-$300 range when the aluminum/plastic one is around $100.

What I love is how people bemoan the plastic/aluminum radiators, calling them cheap and oft to break. When someone starts on a tangent of how great copper/brass radiators used to be back in the day, how they caused no problems, I also comment that back in the day, people knew how to take care of their cars and knew what a radiator flush was.

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