Learn Why You Can’t Flush An Auto AC Condenser

The Truth About Flushing an AC Condenser

Modern auto AC condensers can’t be flushed because the passages in the condenser tubes are too small. That’s a big change from older condensers that could be easily flushed after a compressor failure. If you own a late-model vehicle with a micro-channel condenser and the shop says they can’t flush the condenser, they’re telling the truth. This article explains why.

Learn the difference between older tube and fin condensers versus the newer microchannel condensers

Some older vehicles use tube and fin parallel flow condensers, and you can flush these older condensers using an AC flushing kit and tool. However, some of the older systems used flat tube serpentine condensers, and those can’t be flushed because the passages in the flat tubing are too small to flush effectively.

With the advent of R-134a refrigerant, carmakers phased out the use of tube and fin condensers in favor of microchannel condensers because they’re far more efficient.  Microchannel condensers that can’t be flushed must be replaced.

What is a flat tube microchannel auto AC condenser?

The whole point of a condenser is to place as much refrigerant in contact with the airflow as possible to remove heat. Flat tube microchannel condensers do much better than the older tube and fin and serpentine-style condensers. The flat tubes are extruded with very small passages that excel at heat removal. That’s the good part. The bad part is that the microchannels are so small that they clog with system debris and sludge, and can’t be flushed out because the passages are so small.

What causes an AC condenser to clog?

• Debris from aging rubber hoses, seals, and plastic parts.
• Metallic wear particles from the AC compressor
• Sludge and acids from moisture contamination.
Because the microchannels are so small, they become the “filter” for any debris in the system.

Replacing the condenser and receiver/dryer gives you a fresh start with a new compressor

Most compressor manufacturers require not only a condenser replacement but a receiver dryer replacement to maintain the factory warranty. They simply don’t want any debris breaking loose and damaging the compressor.

©, 2020 Rick Muscoplat