Recharging a Car’s AC
Most of us start seeing ads in the spring for car repair shops offering deals on recharging your car’s air conditioning in time for the coming summer. Which makes us ask, what is recharging the AC? Is it required, like an oil change? Does my car’s air conditioning need to be recharged? Is this another scam that repair shops can pull on unsuspecting customers?
The answer to that last one is definitely no; recharging the AC is not a scam. It simply means that fresh refrigerant is added to the system. If the refrigerant is a bit low, it can be topped off, the same as if you were a bit low on oil in the engine. If it’s really low, though, whatever refrigerant is still in the system needs to be drained out and replaced. This process of clearing out the system and adding new fluid is called recharging.
In either case, you’ve lost some refrigerant, which isn’t so great. Even though R-134a is better for the environment than Freon, the Environmental Protection Agency would rather not have any air conditioning refrigerant leaking into the soil and rivers. If you’re going to have the system drained and recharged, the EPA recommends having the technician take a look at the system to find the source of the leak and fix it.
R-134a is currently the refrigerant most tested and recommended by manufacturers.
A/C system lubricants are ones specifically made for use in A/C systems. The purpose of these special oils is to provide lubrication for the compressor.
Currently, many original equipment passenger car and light truck use R134A synthetic lubricant called polyalkylene glycol, or PAG for short. The switch to this type of oil was necessitated by the fact that mineral oil does not serve as a suitable lubricant for use with R-134a. PAG is also specified by the vast majority of vehicle manufacturers as the lubricant to use when retrofitting a CFC-12 system to use HFC-134a.
Newer systems are equipped with R1234yf or CO2 as refrigerant. This calls for the use of a premium grade PAG oil.
There is one other type of synthetic lubricant marketed for use in automotive A/C systems, called polyol ester, or POE or ester for short. This lubricant is specified by a very few vehicle manufacturers for use when retrofitting certain models of their older CFC-12 systems, but for no other applications.
Use of the correct (vehicle manufacturer approved) refrigerants and lubricants is critical for proper system performance, durability, and longevity.