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Car air conditioning

Don’t Wait To Fix Your AC Compressor Before It Gets Too Hot

When it comes to fixing car AC compressor problems, most people wait as long as possible before looking for a solution. However, what would you think if we prove to you that waiting may be the worst course of action, as it will potentially force you to replace the compressor with a new one?

That’s just the topic of this article, to show you why it’s not a good idea to wait until the compressor gets too hot before fixing it.

How does a car air conditioner work?

The car air conditioner comprises four main components, the car AC compressor, the condenser, the expansion valve, and the evaporator. Each has a crucial role in the air conditioner’s operating cycle, which we will explain below.

  1. What does a car AC compressor do? The car air conditioning compressor performs three primary functions, creating a vacuum on the evaporator side, pumping the refrigerant through the system, and increasing the pressure/temperature on the condenser side. The air conditioning system’s performance depends largely on the difference in refrigerant pressure between the compressor’s inlet and outlet, which is why keeping this component in good condition is so important.
  2. What is the function of the AC condenser? As its name suggests, the condenser’s function is to make refrigerant go from superheated gas to saturated liquid, in other words, carrying out a condensation process. Although an enormous amount of heat is released into the environment during this process, the liquid refrigerant still maintains a very high pressure and temperature, so it has to pass through an expansion valve.
  3. What role does the expansion valve play in the process? For the refrigerant to cool, the air must be at temperatures below zero; however, the refrigerant is at a very high temperature at the condenser outlet. This is because the temperature and pressure are closely related, and remember that the car AC compressor previously raised the pressure. This is where the expansion valve comes into play. When the liquid refrigerant passes through this valve refrigerant’s pressure drops, and therefore, also its temperature. So at the outlet of the expansion valve, the refrigerant retains enough pressure to pass through the evaporator but at a lower temperature. Add the vacuum on the compressor’s suction side, which helps lower the pressure/temperature, and you will have all the elements necessary for the next phase change of the refrigerant to occur.
  4. What does the AC evaporator do? The purpose of the air conditioning evaporator is to carry out the reverse process of the condenser, which is making the refrigerant pass from liquid to gas. This is only possible by absorbing heat from the air that is passed through the evaporator by the air conditioning fan. This is precisely the basic principle of air conditioning systems; the hot air causes the refrigerant to change phase and cool down during the process. Once the refrigerant evaporates, it is ready to be suctioned back into the car AC compressor and repeat the cycle.

How does the car AC compressor work?

Regardless of whether the automotive AC compressor is a variable, reciprocating or rotary, it has the same purpose of generating vacuum at its inlet, increasing refrigerant pressure at its outlet and thus keeping it moving through the system.

New AC compressor after installation in a car

To achieve this goal, the AC compressor uses a pulley driven by a belt connected to the engine block’s head pulley. However, unlike other engine accessories such as the alternator or the steering pump, the car AC compressor is not in operation all the time. The AC pulley is integrated with an electromagnetic clutch that is activated when you turn on the air conditioner. Once the AC system is in operation, a thermostat is responsible for activating and deactivating the AC compressor clutch to maintain the desired cabin temperature. Simply put, your car’s AC compressor is driven by the engine every time the clutch is activated.

Why you shouldn’t wait to fix your AC compressor

Since the compressor is a mechanical component, its internal parts are subject to wear and tear. Moreover, since the car AC compressor has to withstand high temperatures is also subject to thermal wear. This explains why you should not wait to fix your AC compressor. When you do not perform proper maintenance, the delicate balance of pressures in the system is broken, which, in turn, affects the air conditioning system’s performance. This situation strains the compressor and causes it to start overheating. Among the factors that affect the behavior of the AC compressor are.

Auto AC Compressor being cleaned and serviced on a work bench

  • Refrigerant leaks. When the amount of refrigerant in the system is not adequate, all pressures are affected, and this causes the compressor to work intermittently and overheat.
  • Faulty AC compressor clutch. If the compressor runs continuously without a break, it will soon suffer irreparable internal damage due to excess heat.
  • Heat transfer efficiency. When the evaporator or the condenser accumulates dirt and dust, their capacity to transfer heat drops drastically. This directly affects the refrigerant temperature and, therefore, the temperature of the AC compressor.
  • Compressor oil level. Just as it happens when the oil level in your engine is low, when the compressor does not have enough oil, its parts are not properly lubricated, and its temperature rises.

Simply put, if you wait too long to fix AC compressor issues, you will be forced to replace it with another unit, bringing us to our next point.

How much does it cost to replace a car air compressor?

Believe us that it is much more economical to do timely maintenance to the air conditioning system than to wait for the compressor to fail. A new car A/C compressor can cost anywhere from $200 to $900 depending on your vehicle’s make, model, and year. Add to that the cost of labor, which can be up to $300 in some cases. Nevertheless, even if you perform routine maintenance on your A/C system, at some point, you may be forced to buy a new one. That’s when purchasing a used car AC compressor online can significantly drop the total cost. When you buy a used part from a reputable company such as My Auto Store, you can save a lot on the car AC compressor replacement cost. Browse our used AC compressors here. All of our AC compressors are quality tested and ready to shipped to your door for free.

Final thoughts

The first reaction is not always the right one. This applies to problems related to your vehicle’s AC compressor. As you have seen throughout this article, waiting too long before fixing it can lead you to Google “car AC for sale” much sooner than you might expect.


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