Auto Tech

A/C Pro recharge kit: A DIY fix for aging car air conditioners

We test A/C Pro's claim that it can have your car's worn-out air conditioner blowing cold in just 10 minutes.

A/C Pro recharging
The A/C Pro system comes with everything you need to recharge your car's air conditioner. Antuan Goodwin/CNET

There's a lot of snake oil and questionable products lining the shelves of the average auto parts store. From octane booster to VTEC fluid (ha!), it's hard to separate the genuinely useful products from the chaff. So when A/C Pro sent me a few canisters of its do-it-yourself air conditioning recharge system, I was a bit skeptical.

The idea is that most aging car air conditioning systems that don't blow as cold as they should suffer only from low levels of refrigerant. The way A/C Pro works is that you plug a can into your car's air conditioner and simply refill the system with R-134a refrigerant and the necessary lubricants to rejuvenate aging seals and moving parts.

I've laid out detailed instructions for using the A/C Pro product in the gallery below. Check it out for photos and a full walkthrough.

Putting it to the test
With the car running and the air conditioning system powered on, I located the air conditioner's low side connection port. Air conditioning systems are essentially split into two parts, the low- and high-pressure sides, and the cooling happens as the refrigerant is compressed and passes from a state of high pressure to low pressure. After locating the low-pressure connection point, I used the A/C Pro's gauge to measure the pressure of the system. (Be sure to keep your hands clear of moving parts; I got a nice friction burn on the back of my hand from a moving accessory belt.)

If the pressure looks low, then it's time to refill and recharge the system using the A/C Pro product by pulling the trigger on the filler nozzle. The filler nozzle and pressure gauge combo gives feedback and control over the refilling and the user should take care not to overfill the system, which can adversely affect the system's ability to chill air.

Our test car, a 1999 Toyota Corolla, was blowing 84-degrees-Fahrenheit air at the beginning of the test. I saw a 20-degree drop in vent air temperature to about 64 degrees. That's a big-enough jump to prove that the product does work -- at least as a short-term fix. Systems with moderate to large leaks could eventually depressurize again and may still need a mechanic's help. A/C Pro tells us that for the vast majority of systems, this simple recharge should be enough.

Air temperature
After the air conditioner in our test car was recharged, the blown air temperature dropped by about 20 degrees. Antuan Goodwin/CNET

All in, prepping, measuring, and recharging the system took me about 30 minutes. However, the Corolla's pressure levels were exceptionally low and I took more time than I probably needed to measure air temperatures and take photos, so it's still a fairly quick fix.

I should note that the Corolla was actually my second attempt to test the A/C Pro product. My first attempt was under the hood of a 1990s vintage Volkswagen Jetta. Unfortunately, this system had bigger problems than the A/C Pro product could fix. There's only so much that a simple refilling, recharging, and lubricating product can do. If there's physical damage (such as a seized compressor or a serious leak), you may need more help than A/C Pro can supply.

Still, for only about $45 to $50 at your local auto parts retailer, A/C Pro isn't a bad DIY first step before calling in a professional (and potentially expensive) mechanic.