AC Class Complete

Air Conditioning machine doing its thing.
Blue line to low pressure side, red line to high pressure side.

My summer term at York Technical College just ended, and it included two classes, Brakes and AC. Both of those systems come in mighty darn handy if you’re driving in the summer! If I had to pick one that was more important than the other, I'd have to go with brakes. 

It's a good idea to use this machine to analyze WHAT kind of refrigerant a car has in it. Here the display confirms there is NO R12 or R22 and no HC. Another screen confirmed it was 100% R-134a.

I knew next to nothing about the AC system, so it was fun to learn how it works, and then with the rest of the students we worked on a bunch of cars and trucks. Once you understand the basics it’s not too difficult to start diagnosing AC problems. Also, the machines that can recover, recharge, and handle the refrigerant and read the high and low side pressures are almost Terminator/Matrix like because they basically tell you what to do. Maybe there’s a Sci-Fi movie plot there, "2025, The Rise of the Air Conditioning Machines!"

One car I worked on was this NMS 2007 Nissan 350Z. 
Removed the AC compressor, condenser, and some lines. 
With maybe 20 pounds less weight, I bet it goes twice as fast!

While I'm talking about this, where do you suppose those vehicles that our classes work on come from? Most of them come from students, and some belong to people that work at school. So, my tip of the day, just like getting your hair cut at a local barber school, or dental work from a local dental school, you might be able to get some work done on your car by a local automotive school! I'll point out that the school has car owners sign a form to acknowledge that we're students working on their car, and that we're not responsible for any problems, and there is no warranty. Hey, you get what you pay for in life! In AC class, the school only charges for parts and refrigerant used. Given the cost of labor at a garage, that's a pretty good deal. 

Smart machine, it tells me what to do next, check the oil bottle.
Your AC refrigerant has oil in it to lubricate the system components.

One bonus in this class was taking and passing the ASE certification for operating AC machines and handling refrigerant. Yes, I passed, with a 93%, thanks for asking! 

Your cabin air filter plays a role in keeping your car cool with AC and warm with heat, so check it out once in a while. About 80% of cars have these filters now. 

By the end of the class I felt confident about understanding the AC system and components, how they work, and how to repair them. It was a five-week class, but the time went quickly with most of the time in the shop working on cars. Most of the students in my class range in age from say 17-24, with some of them dual enrolled in high school and the Automotive Technician program. Most of them are currently also working in garages and car dealerships around the area, so they're getting plenty of experience on all things automotive. 

Here's something you don't see every day, an AC system Thermal Expansion Valve. One was removed from a BMW because it was leaking, and the other is the new one. We didn't have to take the entire dash out, so it was not as bad as some AC repairs.

One thing some of the students discussed in this class was that you could probably go out and buy a high-speed AC machine and go into business. While that's true, if you're certified, you'd have to buy the machine in the first place, and we'll say an average one starts at $10,000. We ran that idea by our instructor, and he said sure, you'd do OK, and probably pay off the machine in the first summer. Of course, you may not be getting much AC work in the winter, buy hey, it's an idea! Maybe a bit more realistic than trying to win the lottery!

You can work on AC without the machines, just head down to your local auto parts store and hand over say 100-300 dollars for an Automotive AC gauge set, and you can start working too!

One exercise we did for this class was disassemble and put back together an AC compressor. It kind of looks like a satellite or something from Star Wars.
 These are usually replaced instead of repaired, and now I know why.