Here’s a question: After we repair it, how long would you like your air conditioning system to work?

If your answer is “For a long time”, “For many years”, “Forever” or anything similar, then we believe that – once you understand how complex and expensive air conditioning systems can be to repair – you’ll appreciate the My Garage approach.

What does it cost to recharge my air conditioning system?

This is a question that we receive constantly during the summer months. For those not familiar, recharging refers to the process of adding or “topping up” the refrigerant in an air conditioning system. (There’s more to the process than that, but let’s keep it simple for now.) Refrigerant, or “freon” as we used to call it, is the chemical that makes the system work.

Among car owners, low refrigerant is the most well-known cause of poor A/C performance, so when clients ask for an air conditioning recharge, most are really telling us that their system just doesn’t cool properly – and it needs to be inspected. Why’s that? Well, low refrigerant is just one of at least a dozen reasons your air conditioning system might be on the fritz. Plus, if your refrigerant is indeed low or empty, that’s usually not normal.

In this article, we’ll explain a bit more about how automotive air conditioning works, as well as how to properly test and repair it.

Low refrigerant? How often should a vehicle need to be recharged?

Wait, didn’t we just say there’s usually more to an unruly A/C system than low refrigerant? That’s true, and we’ll get to that in a second. But while we’re on the subject, how often should an air conditioning system actually require a “top up”?

In a perfect world, the answer would be “never” since the refrigerant isn’t consumed in any way and it never goes bad. However, in our cold Canadian climate, a tiny bit of leakage can be normal during the worst months of winter, when all of the hoses and o-rings contract due to the extreme cold. This means that here in Alberta, otherwise healthy air conditioning systems typically require a recharge about once every 10 years.

If your refrigerant is low today but you’ve had it filled within the past 5 years, or if it’s low and your vehicle is less than 8 years old, you have a leak.

Can you recharge a leaking air conditioning system? After all, A/C repairs are expensive, and refrigerant is cheap – right?

Unfortunately, the answers to these questions are “no” and “no”. Here’s why:

1. It’s actually illegal to refill an air conditioning system with a known leak. That’s because while they’re cleaner than they used to be, automotive refrigerants are still ozone-depleting, so we can’t be venting that stuff into the atmosphere.
2. Air conditioning repairs are expensive, you bet – more expensive than they’ve ever been, given how complex vehicles are today. But these days, so is refrigerant. Vehicles from 2018 and onward use a new refrigerant called R1234yf, which costs about ten times more than the older R134a used to. We’re saying “used to cost” because R134a is being phased out and production is ramping down, with these supply constraints already doubling the price over the last couple years. This means that recharging a leaking system could be an expensive mistake when your money literally evaporates into thin air.

Aside from low refrigerant, what else would cause my air conditioning not to work?

About 30% of the vehicles that come to My Garage with poor interior cooling are low on refrigerant. The other two thirds have something else wrong, or a combination of issues. These can include, but are definitely not limited to:

• In-dash airflow or temperature mixing issues: The A/C system is making cold air, but it’s not getting into the vents. This could be due to a plugged cabin air filter, broken temperature door in the heater housing, faulty temperature door actuator/motor and more.
• Compressor engagement problems: The refrigerant system is full but the compressor doesn’t engage due to a failed relay, failed clutch coil, a plethora of common wiring issues and more.
• Pressure issues: The refrigerant system is full and the compressor engages, but the operating pressures are out of whack due to restrictions or blockages, expansion valves that don’t cycle properly, orifice tube problems, etc.
• Condenser airflow problems due to plugged radiators, cooling fans that don’t operate properly, or other issues like a “Saskatchewan thermostat” left behind the grille after winter!

Here’s how the My Garage air conditioning diagnostic process works.

As we mentioned, air conditioning repairs today aren’t cheap. None of us can afford to pay twice for the same repair, or to pay for repairs that we don’t need. To service your air conditioning system more accurately and more completely – with better results – than anyone else, we have developed a systemized air conditioning inspection and diagnostic process. It’s a logical, experience-based process that covers all the steps required to troubleshoot your system completely with no wasted time. Nothing you don’t need, no guessing, just straight to a properly diagnosed and guaranteed repair.

Our process starts with a $179 general inspection of your entire air conditioning system. It includes:

• Inspecting your cabin air filter.
• Checking operation of your mode and temperature mix doors within the instrument panel.
• Measuring your refrigerant charge level.
• Measuring your refrigerant system operating pressures.
• Testing operation of your compressor clutch.
• Testing operation of your condenser fans and check airflow.
• Performing a full visual inspection of the system components. (Parts visible without disassembly or interior removal.)

This general inspection might lead to a system recharge, it might lead to a repair of some kind, or it might lead to further testing as described in the diagram above. When we’re done your repair, we’ll back it with our industry-best 3 year/100,000 kilometer workmanship warranty. That’s the longest guarantee in Alberta and three times longer than most Airdrie service centres.

Many poorly functioning A/C systems have multiple issues.

This is part of the reason for our full system diagnostic approach. With air conditioning, we’ve learned not to stop at the first problem that we find, because many vehicles have multiple issues. When your mechanic only catches one of them, this can result in the inconvenience of more vehicle downtime and having to make a second repair appointment, further unexpected expenses or even money wasted doing things twice – like recharging a system twice because all of the leaks were not identified.

This actually happens all the time with refrigerant leaks. With a less thorough approach than ours, it’s common to find an obvious leak, repair it, recharge the system and then see the air conditioning fail 1-2 months later because a second, smaller leak let the refrigerant escape again. In that situation, hundreds of dollars are wasted paying for another fill/recharge following the second repair.

Let’s talk about those pesky refrigerant leaks, how difficult they are to locate, and why some leak testing techniques just don’t work.

Refrigerant is tricky to explain. Within your vehicle, it exists as both a liquid and a gas at the same time, constantly evaporating and then condensing again. When refrigerant leaks out of the system, it’s usually in the gaseous state – a totally invisible, mostly odourless gas. Combined with the fact that many A/C system parts are buried deep within the vehicle, you can imagine how tough this makes finding some refrigerant leaks! Here are some of the techniques that auto repair businesses use to locate refrigerant leaks.

Degradation of vacuum testing:

This is the most commonly used leak test; it’s built into every air conditioning recovery & recharge machine. It also doesn’t work. A degradation of vacuum test involves using suction to pull the system into a full vacuum of at least 25 inHg, with no refrigerant or air left inside. After that, the system is left alone for at least 15 minutes. If the vacuum level doesn’t change, it is assumed that the system must be completely sealed. In reality, this test will only catch the largest and most obvious refrigerant leaks; a vehicle can pass this test and then leak out its refrigerant charge in the same day. As stated by an instructor on a training course that we attended last year, “Why would you use vacuum to test a system that operates under pressure?”

If a mechanic tells you that they “checked for leaks” before recharging your system, especially in a dealership or commission-based shop where technicians are rushing, this is likely the only test that was performed.

Nitrogen pressure testing:

This test involves filling the air conditioning system with nitrogen and then spraying components with soapy water or another leak detection solution, while watching for bubbles that would indicate leaks. In practice, nitrogen pressure testing will locate more leaks than a vacuum test, but usually just the medium-to-large sized ones. Slower leaks, where the refrigerant takes days or weeks to escape, typically can’t be pinpointed this way. Nitrogen pressure testing is also limited by the fact that some components are located behind your instrument panel, inside a fender, or somewhere else they cannot be accessed to spray with liquid.

Filling the system with refrigerant and adding UV dye:

As an industry, this used to be the most accurate testing method that we had. Under a black light, UV dye sometimes leaves very visible evidence of where refrigerant has escaped. Testing this way will reveal about 75% of refrigerant leaks, including some of the smaller/slower ones. However, there are three issues with UV dye testing:

1. The UV dye is carried through your air conditioning system by the refrigerant oil – did we mention that there’s oil in there? – not by the refrigerant itself. This means that it’s usually most effective in identifying leaks within the liquid side of the system and not the gaseous side. When refrigerant escapes as a gas, no dye is left behind.
2. Even when the dye escapes, some leaks just aren’t visible because you can’t see the components. This might include the backside of a condenser that’s against the radiator, the “clean side” of your evaporator core, etc.
3. This method is wasteful and expensive, since it literally requires letting the system leak out this increasingly-expensive refrigerant. In the case of a newer vehicle with a slow leak, diagnosing it this way might require a client to pay for a $700 recharge that is wasted!

Leak testing with carbon dioxide at My Garage:

This is the gold standard in air conditioning refrigerant leak testing. As industry leaders, we’ve made the nearly $9000 investment in the ATS Bullseye CO2 leak detection system, the most advanced leak detection tool on the planet. Using this equipment, we start by pressurizing your A/C system with carbon dioxide. This is the smallest system-safe molecule and being smaller than refrigerant, it helps leaks show more quickly. Using the IR CO2 sensor, we then locate where the gas is escaping. Once the problem area is found, a pinpoint confirmation can be achieved by spraying the area with a patented clingy foam that changes colour where the CO2 is escaping.

Adding capability like this wasn’t just an investment in our business, it’s an investment in you – part of our commitment to offering longer lasting repairs, better service and better value for your money.

Are you ready for an accurate diagnosis and a lasting repair, with the best guarantee in Alberta? Let’s talk! Please contact us any time.