AC Repair Basics

AC Repair Basics

Now that the summer is over and temperatures are beginning to drop, I'm taking a moment to be thankful for another year with air conditioning. It's one of the systems in your can that you may be able to live without, but it improves the quality of your driving experience to have. There are a lot of questions and misconceptions behind how it works and ways to perform repairs yourself. We and our partners at Kelly Paint & Body, Inc. here in San Antonio, TX have compiled a short list to give a little more information that could save you money, or in some cases your life.

First, there are two basic types of refrigerant that vehicles use. Prior to 
1994, the type used was R12. After then, regulations mandated the use of R134a, which is much better for the environment. In most cases, you can't use one in a system designed for the other, as the difference in operating pressures are not compatible. To get newer refrigerant into an older system, you will probably need to at least replace all of the seals, and at most replace the pump and condenser. 

A small amount of refrigerant is lost over time, but it's far less than even a few years ago. On average you'll lose .41 oz of it per year. This means for the average owner, you may never need to recharge the system. If you do within the first ten years of ownership, you probably have a leak or blown seal. 

When you notice your AC is blowing warmer than it should, leave it off. Refrigerant also contains a lubricant for the system. If you're low on one, you're low on the other. Running any system in your vehicle dry is never a good idea. 

There are a few interesting misconceptions as well. Some people believe that refrigerants include butane and propane.

That's just not true, as they would almost certainly result in combustion.

That's probably counterproductive to an air conditioning system.

This last one is of particular interest. There is a popular rumor that keyboard cleaner (R152a) can be used as automotive refrigerant.

It's extremely flammable. There are a lot of videos on YouTube where people recharged with air duster, only to fire up their system just to find flames jetting out of the air vents toward occupants. Best to avoid doing this at all costs.

With these few things in mind, you now know the basics of modern automotive air conditioning.

If it's getting a little warmer than it should, it can be repaired by a quick trip to a local service shop, or better yet the service drive at your local dealership.

For safety's sake, it's best to let the experts handle this one.

Written By: Todd Hendrickson
Source: Popular Mechanics