Put your A/C on all the way cold, recirculating and the highest setting. Let it run for 3-4 minutes at least before proceeding to the next step. This ensures that your system will be attempting to draw the refrigerant through the pipes, which is what we want.
Every vehicle that has air conditioning should also have a high and a low pressure a/c service port. They’re typically aluminum tubes, one thicker and one thinner. They also have removable caps on them labeled with an ‘H’ and an ‘L’ respectively. Locate the low pressure service port and remove the cap. It should either thread off or just pop off. Be sure to put it somewhere safe.
The refrigerant you purchased should have come with a pressure gauge. The adapter on the end is identical to that of an air compressor hose. Pull up the collet and attach the adapter to the low pressure port. You should get a reading on your gauge. If you’re pretty much out of refrigerant, or very low, you’ll likely get a reading between 0 and 15 PSI. That means it’s definitely time for a recharge. If, however, your reading is in the blue zone (typically above 30 PSI) you might not need refrigerant and may have a different issue altogether. Be aware that over filling your refrigerant can be harmful to your system and may cause the same lack of cold air as an under-pressured system.
Once you’ve determined that you need more refrigerant, start shaking the can. Its contents need to be well agitated to mix up the settled contents. Keep shaking throughout the next steps as well.
Check the included chart to determine what PSI you need to be at, which is determined by the outside/surrounding temperature. If you’re in a room temperature garage, for example (70 deg. F), then you’ll need your low pressure to be at 35-40 PSI. If it’s 100 degrees out, you’ll need to be up at 50-55 PSI. Keep moving the can horizontally and vertically as you squeeze the trigger to pressurize the system. Be sure to stop from time to time to check the pressure level so as to not over-fill it.
That’s it! You should have functioning A/C again – woohoo! If you’ve been without it on a scorching hot day and then get it fixed, you know what a joyous occasion this can be. In this case, I was working on my Dad’s old truck and he actually has never had A/C in it since he bought it a couple of years ago so you can imagine how pleased he was to feel the ice-cold air blowing out of the vents. Summers are suddenly much more bearable!
Ready to watch the video to see it in action? Check it out.