Air Conditioning Repair

Note from 2022 – This is a very old article and while some of the information is still valid, it’s not as relevant as it once was. Please read one of our more recent air conditioning articles instead.

Air conditioning repair is one of those repairs that requires the customer know what to expect, otherwise it’s likely they won’t be happy with the outcome. So, if you are planning to have us service or repair your A/C, please take a minute or two to read this page.

How often should you service your A/C system?

We only recommend servicing your A/C when it is not performing well. An A/C service is not like an oil change, something that must be done on a schedule to maintain the car. Why do so many people think A/C needs a yearly service? Well, because that’s the way it used to be. In the “old days”, people would bring their cars to a mechanic to have their AC systems serviced before the summer. Why? Because most systems leaked so much that they needed yearly service.

Small AC system leaks were hard to find using older equipment, and fixing smaller leaks was not cost effective since R12 was very cheap. Unless a system leaked so much the car wouldn’t make it through the summer, people didn’t want to pay to fix it. Now we take leaks very seriously because the refrigerant is bad for the environment when released, and if that’s not enough of a reason, it’s also very expensive. We have improved methods for finding small leaks, so there’s no reason for a system to be serviced on a schedule.

Why do A/C systems need service at all?

Automotive air conditioning systems are likely to need more frequent service than those installed in homes or refrigeration equipment because they are subjected to the heat, vibration, and movement that goes along with being in a car. The length of time a charge can last varies. We’ve seen some new cars lose their charge in as little as a year, and then there are some people with working A/C on 10 year old cars that claim they have never charged the system. Average life on a charge seems to be between 2 and 5 years.

What goes wrong with A/C?

The most common problem with air conditioning is low charge. In other words, the R12 (AKA Freon)or R134a has leaked out of the system and as a result, the A/C no longer works. Less commonly the A/C compressor belt can break, the A/C compressor clutch can become damaged, the compressor can become damaged, there could be a restriction in the system, a problem with the blend door causing the heater to cancel out the A/C, or electrical problem that prevents the clutch from engaging.

Where do we start?

The first step is to check the A/C compressor clutch belt to make sure it is there and tight. If space allows, we spin the compressor by hand to make sure it is not frozen. Next we check to see if the compressor engages when the button is pressed. If not, we attach a recovery machine then remove and weigh any Freon in the system. If there is too little or no Freon in the system, we recommend a A/C service. What if we find the a/c system was full? Then we look elsewhere for the cause of the problem. The cost of diagnosing an A/C system that is not low on charge depends on the amount of time it takes.

What’s an A/C service?

If we determine your system is low on charge we do an A/C service. This consists of removing all the Freon and weighing it, replacing the Schrader valves (a very common and easy to fix leak), vacuuming the system to remove air and moisture, adding ultraviolet dye to the system, charging the system to manufacturers specifications, checking operating pressures and vent temperature, and finally, checking for leaks using a black light. If all goes well and the system works and appears leak free, we give you your car back and ask you to drive it for a week or two then bring it back for a follow up UV dye check to find any smaller leaks.

Can’t you just add some Freon to my system instead of the expensive service?

No. It’s illegal for good reason – it’s bad for the environment.

What if I have a leak?

The options are paying to have it fixed or recovering the Freon and living without A/C. We will give you a price for the repair if we find a leak. You will not get a refund for the A/C service if you have a leak. There is no guarantee that if we find a leak that it will be the only leak. It may be that there are slower leaks that have not shown up yet. If we fix a leak, then it’s best if you come back for another follow up UV dye test. We do not charge any extra for the second leak check after a repair.

What about converting (retrofitting) my pre-1994 car to ozone friendly refrigerant?

Up until recently, we did not recommend this because of cost and the problems associated with putting a refrigerant in a system not designed for it. However, with the cost of Freon skyrocketing and it becoming obvious it will soon be impossible to get it at any price, we are now changing our recommendation. If you plan to keep the car for a while (at least 2 years) and you want the A/C to continue working while you own the car, it may make sense to convert to R134a.

What are my conversion options?

There are other conversion alternatives (about 20 different formulas) but R134a makes the most sense because it will not be “disappearing” any time soon. With 20 different refrigerant blends out there it is obvious that not all of them will survive and become the standard. In fact, it’s unlikely any of them will be sold in 5 years from now. So if you put one of those blends in, what happens next time you need a service? Yet another conversion? And how are you any better off than if you stuck with Freon?

There are 3 problems with converting to R134a:

  • It is not as efficient a refrigerant – it will not work as well as Freon in the same system. How well it works depends on you’re A/C system. Mine works the same as before.
  • R134a has a smaller molecule and is more likely to leak out.
  • R134a creates higher pressures and is probably harder on A/C components.

What’s involved with converting to R134a?

The EPA says you must change all the service ports and install an under-hood sticker so that Freon is not accidentally installed at a later date. The oils used for Freon and R134a are incompatible. Therefore, as much as possible of the mineral oil used for Freon must be removed from the system. This is done by removing the compressor from the car and draining it into a container, draining or better yet replacing the receiver dryer, and flushing the condenser and lines with a pressurized flushing agent.

All of the O-ring removed during this operation must be replace with a type designed for R134a. In my opinion all O-ring and hoses in the system need not be replaced during a conversion as some mechanics recommend. They have been soaked in mineral oil during their service and that will prevent the R134a from leaking. (The conversion is way too expensive otherwise).

However, any O-ring or hoses replaced at a later date should be the type designed for R134a. Then the system is charged to about 3/4 its original specification and the rest is just like the standard A/C service. You will definitely find other mechanics with different opinions on how to do a conversion. Our procedure costs a lot less ($800 -$1500 less), seems to work fine, and follows all the EPA guidelines.