Toyota AC Service and Systems

Air Conditioning Service and Repair at Atlantic Toyota of Long Island

Toyota Air-Conditioning Systems

Toyota Air-Conditioning (AC) Systems operate like all the other car AC systems out there; you turn them on, cold air blows out, and soon the inside of your hot car has cooled down. Not much to it. But have you ever wondered how this magic works? Just exactly how do you “make cold air” anyway? Read on and we will make you an expert (well, sort of) on AC systems.

Making cold air

So technically, the title of this section is wrong. The AC system in your Toyota doesn’t “make cold air,” what it really does is “remove heat from the hot air.” Huh? Maybe we should look at this another way. Let’s see how a scientist would explain this. First, objects in our world range from very cold to very hot. A scientist would explain this as such: “If you want to make something hotter, add heat. Want to cool it down, then remove heat.” So according to scientists, what air conditioners do is “remove heat from the hot air.” We will pause now and let that sink in.

How your Toyota does this

Let’s think about the typical automotive AC process. The compressor compresses a gaseous refrigerant to a pressure of about 200 to 250PSI. The condenser acts like a radiator by giving off heat. This happens inside your car’s engine compartment usually right behind your radiator. When this heat is released, the refrigerant gas turns into a liquid.

From the other side of the condenser, the “Liquid Line” connects to the Orifice Tube. At the orifice tube, the liquid refrigerant squeezes through a narrow passage yielding a temperature and pressure drop. After the liquid passes through the orifice, it gets cold and this cold refrigerant flows to the evaporator.

The evaporator is also set up like a small radiator with the refrigerant circulating thru it. A small fan blows air across the cold evaporator which removes the heat from the air. The cold surface of the evaporator also condenses humidity out of the air which it allows to drain under the car. Finally, the refrigerant travels back to the condenser and the process starts over again.

Refrigerant 101

In 1990, the federal Clean Air Act dictated that manufacturers cease production the industry standard R-12 refrigerant because it was contributing to the destruction of Earth’s Ozone Layer. The result is that all vehicles starting from 1994 and on came with R-134a refrigerant. R-134a is not like the old R-12 Freon, it is a  tetrafluorothane which is a hydrofluorocarbon (HFC). HFC refrigerants work almost as well as R-12 but are far less harmful to the ozone layer.

Refrigerant Oils

It is important to know that oils circulate along in your AC system along with the refrigerants. And R-12 and R-134a each use a different type of oil. Mineral Oil was used with R-12 refrigerant and synthetic polyalkyline glycol is used with R-134a refrigerants. Your mechanic will know this.

Keeping your AC system healthy

OK, thanks for sitting through Automotive AC Systems 101. Let’s now look at what you can do to keep your AC system healthy.

First, run the system a few minutes at least once a week no matter how cold the temperature outside might be; here’s why: this ensures that the many hoses, valves and pumps throughout the AC system are kept well lubricated by the refrigerant oil which we discussed above.

Second, whenever you have the car serviced, make sure you ask the mechanic to check the refrigerant level and top off the system if necessary. Your Toyota mechanic will connect up a set of special gauges to your AC system and they will be able to see how much refrigerant is present and what pressure it is at.

Last thing, it is good practice to get a full air conditioning service at least once a year. Try and do this before the hotter months start, for obvious reasons!