Why Do Automotive AC Lines Corrode?

Your car's air conditioning system uses a closed refrigerant loop. Under normal operating conditions, pressure on the high and low sides of the system remains relatively constant. So long as the plumbing stays sealed, your refrigerant will not break down or wear out over any reasonable timespan. Unfortunately, few cars ever achieve this level of indefinite theoretical performance.

In most cases, vehicles require system recharges due to refrigerant loss. Small leaks in pipes or fittings can allow refrigerant to escape over time, breaking the closed loop and reducing system pressure. As the pressure drops, your system efficiency falls, and you risk damaging other components. Although leaks can occur for many reasons, corrosion is an especially common cause.

Understanding Your Refrigerant Loop

Your car's refrigerant loop is similar to that found in any other air conditioning system—refrigerant cycles from the high-pressure compressor's side to the low-pressure evaporator's side. On both sides, coils help the refrigerant to either absorb or release heat. For modern vehicles, the refrigerant travels through the system in aluminum AC lines.

These coils and pipes are the two most likely culprits for any leak. Since the coils contain many small passageways for refrigerant to flow through, they can be particularly troublesome sources for leaks. Frequently, holes are small enough that you will only lose a small amount of refrigerant, causing subtle issues before your system fails.

Coming to Terms With Corrosion

Physical breaks in AC lines are rare. Instead, leaks typically develop as a result of corrosion. The reactive nature of aluminum makes it highly resistant to corrosion, but acids can break down its protective layer over time. When your aluminum lines wear away from corrosion, small pinhole leaks will develop. These leaks are similar to those found in residential copper plumbing.

Corrosion can lead to several potentially severe issues. Reduced pressure can stop your AC from working, ultimately stressing and even destroying the compressor. Additionally, small flakes of corroded metal can contaminate the system, potentially clogging the coils or damaging other components. Ignoring corroded AC plumbing can quickly lead to costly repairs.

Addressing Corrosion Problems

Anytime your car's AC seems to be struggling, you should have the system evaluated by a professional technician. Most shops will refill your air conditioner with a special dye-impregnated refrigerant, allowing them to locate the source of the leak.

Once technicians find the source of the leak, they will flush your system and replace any damaged components. Flushing the system is vital to remove rust build-up and clean out contamination, ensuring that your repaired AC system continues to function correctly.

To learn more about broken AC repair, contact a company like Modern Auto Air.