Auto Parts - How to Recharge Your Car’s A/C

Canadian summers can get extremely hot, and there’s nothing worse than realizing your A/C isn’t blowing cold air while you’re stuck in traffic or just starting out on that long summer road trip. On the bright side, temporarily restoring your car’s A/C’s refrigerant levels is one of the simplest DIY jobs. But it’s important to know if your car needs a recharge before you buy any necessary supplies.

Is a Recharge Actually What You Need?

Your A/C system runs on a closed loop, which means refrigerant doesn't get used like engine fuel. Low refrigerant signals a leak.

However, there may be other reasons your A/C may have stopped working :

• broken compressor
• failed condenser fan
• electrical issue

In these cases, immediate professional repairs may be necessary.

Refrigerant loss can happen via a small, slow leak somewhere in the A/C system. Here are some telltale signs:

• Your A/C becomes a little less cool over a few seasons.
• Your A/C cools better at highway speeds than when idling.
• The compressor clutch isn’t spinning with the compressor (or serpentine) belt.

In these cases, a DIY recharge can buy you some time, but it isn’t the same as a professional A/C service. It lets you effectively top up your A/C system as a temporary solution. However, a professional A/C service is still necessary to fully address the leak.

If you notice your A/C suddenly stops working, or if it's been recharged lately and is still underperforming, then you may have a much larger leak that requires professional repair.

What Are the Different Types of Refrigerants?

There are three refrigerant types used in passenger vehicles across Canada. These traditional synthetic refrigerants are strictly controlled and should only be handled by certified technicians during a professional A/C recharge service:

• R-134a is used in most vehicles built in model year 2020 or earlier.
• R-1234yf is used in most vehicles from model year 2021 onwards. This is the newer global standard, since R-134a has a high global warming potential.
• R-12 is only used in vehicles built before 1995.

Using the wrong refrigerant can damage your A/C system. Your certified automotive technician will check which refrigerant type your vehicle needs, as well as the correct charge amount.

A recharge kit does not contain refrigerant, because it is a heavily regulated substance. Instead, it contains hydrocarbon-based refrigerant alternatives. These are extremely flammable and should be used only in accordance with their instructions.

What You’ll Need

To properly complete a DIY A/C recharge, ensure you have the following items:

• A/C recharge kit with a pressure gauge and an ozone-safe alternative
• safety glasses
• gloves
• thermometer

Step-By-Step: How to Recharge Your A/C With a DIY Recharge Kit

Before you start, put on safety glasses and gloves. The refrigerant alternative in your DIY kit is stored under pressure and is extremely cold when released, so direct contact with the skin or eyes can cause serious injury.

Always work in a well-ventilated area and keep the DIY kit away from any heat sources, including the engine, hot surfaces, and any ignition sources.

Once you’re protected, follow these steps for a temporary DIY recharge:

1. Start your vehicle and set the A/C to maximum. Turn the fan to its highest speed and set the temperature to the coldest setting.
2. Let the engine reach its operating temperature. This allows for more accurate pressure readings.
3. Check the compressor clutch. Look at the A/C compressor on the engine. There’s a clutch plate on the front of it that should spin along with the belt when the A/C is on. If it isn’t spinning, a recharge may be worth attempting, since low refrigerant can prevent the clutch from engaging. But this may also be a sign of a larger mechanical or electrical issue that requires professional repair.
4. Find the low-side service port. You’ll attach the recharge hose here. It’s usually on the passenger side of the engine bay, and it should have a black, blue, or grey cap with the letter “L” or “LOW” on it.
5. Attach the recharge hose. Follow your recharge kit instructions to click or thread the hose onto the port.
6. Read the baseline pressure gauge before adding anything. The gauge will show the current baseline pressure in the system. Most recharge kits include a chart with the correct target pressure for the outside temperature. For typical warm-weather operating temperatures, 40 psi is a common benchmark, but this target would be higher on a hot day.
7. Add refrigerant in short bursts. Hold the can of refrigerant upright and squeeze the trigger for five to 10 seconds, then release and read the gauge. Repeat this until the gauge reaches the target pressure for the ambient temperature. Do not overcharge: too much refrigerant can damage the compressor.
8. Check the vent temperature. Follow your DIY recharge kit’s guidelines.
9. Disconnect the hose and replace the port cap. Also ensure you properly clean your work area and safely dispose of any products. Follow all instructions in the DIY recharge kit.

When to Stop and Call a Professional

If you’ve finished your DIY recharge and the compressor clutch still won’t engage, or you recharged the system last season and your A/C still isn’t cold, you probably have a larger issue that requires a NAPA AUTOPRO certified technician. They have the expertise and tools to pressure-test the system, find the leak, and get your A/C back to full power.

With a quick DIY A/C recharge, you can beat the heat and ride comfortably this summer. For the best advice and a wide selection of refrigerant and recharge kits, visit your local NAPA Auto Parts store to speak with an automotive expert or browse our full selection at www.NAPACanada.com.