A/C Compressor Buyer’s Guide
- The A/C compressor is a critical component of your vehicle’s air conditioning system.
- It is made up of a compressor housing (compressor, valves, and oil fill), connection points for refrigerant pipes, and a pulley with a magnetic clutch.
- The A/C compressor is responsible for transmitting cool air into the passenger cabin.
- This component pumps coolant and uses pressure to convert it from gas to liquid, and back to gas.
- There are three common types of A/C compressors include: rotary, scroll, and variable displacement compressors.
- Rotary compressors feature a roller which rotates inside a cylinder that is divided in two by a spring-mounted blade.
- Scroll compressors are comprised of two spiral disks—a rotating shorter disk sitting inside a stationary taller disk.
- Variable displacement compressors, also known as reciprocating compressors, feature a piston-cylinder mechanism that uses the up and down motion of the piston to create pressure variations.
- Signs of a bad A/C compressor include high cabin temperatures, squealing or grinding noises, and magnetic clutch malfunction.
- Identify the exact A/C compressor model of your vehicle and determine whether your car employs R12 or R12. to find the best component.
- The cost of an A/C compressor for cars will vary depending on your vehicle’s specific year, make, and model. OE replacement A/C compressors will typically cost you anywhere between $250 to $3,000. These are available for sale individually or as part of a kit.
What is an A/C compressor?
The A/C compressor is a critical component of your vehicle’s air conditioning system. It is attached to the engine block and is made up of several components, which include: the compressor housing (compressor, valves, and oil fill), connection points for refrigerant pipes, and a pulley with a magnetic clutch. Its main role is to compress the refrigerant within the A/C system.
What is a car A/C compressor for?
Simply put, the A/C compressor is responsible for transmitting cool air into the passenger cabin. This component pumps coolant and uses pressure to convert it from gas to liquid, and back to gas. A properly functioning compressor will give you better temperature control inside your vehicle, keeping you and your passengers cool, even in the summer heat.
How does an A/C compressor work?
When you switch on your vehicle’s air conditioning system, the pulley and V-belt mechanism of the compressor is activated by the magnetic clutch. The refrigerant gas is drawn from the evaporator, causing pressure to drop within the evaporator. This, in turn, lowers the temperature of evaporation for the refrigerant.
The cold vapor produced is compressed and warmed as it is delivered to the condenser via pipes. The refrigerant goes back to its liquefied state, giving off heat in the process. As it is routed back to the evaporator, it absorbs the heat of the air from the passenger compartment and turns back into gas. This cycle continues until the A/C unit is switched off.
What chemicals does an A/C compressor use?
An A/C compressor uses refrigerants to do what they need to do. These refrigerants are fluids that are actually gases that have a low boiling point. These gases can transform from a liquid state into a solid state easily.
Before, the type of refrigerant normally used in A/C compressors is Freon. But, due to its negative effects on the ozone layer, ozone-friendly fluids have been developed and are now being used, instead.
What are the types of A/C compressors?
There are three common types of A/C compressors, which include rotary, scroll, and variable displacement compressors.
This type of A/C compressor features a roller which rotates inside a cylinder that is divided in two by a spring-mounted blade. This movement causes variable pressure to build up in one sealed section, while the cooled compressed gas is forced into the other section.
This type of compressor is comprised of two spiral disks—a shorter disk sitting inside a taller disk. As the short disk rotates, it creates suction that draws the refrigerant gas towards the center of the scroll and compresses it. As this happens, cooled air escapes through an outlet on the taller disk.
Variable displacement compressors
Also known as a reciprocating compressor, this type features a piston-cylinder mechanism that uses the up and down motion of the piston to create pressure variations inside the cylinder and draw refrigerant gas for compression.
What are the signs of a bad A/C compressor?
Get your air conditioning system checked by a licensed mechanic as soon as you observe one or more of the following symptoms of a failing A/C compressor.
Unusually high cabin temperatures
One of the most obvious signs of a bad A/C compressor is unusually warm temperatures inside the passenger cabin despite having the air conditioning switched on. Problems with regulating the flow of coolant will make the system unable to blow cold air for circulation.
Squealing or grinding noises
The compressor’s belt driven mechanism can produce loud noises as components break. Listen for any high-pitched sounds that may point to a leak or a grinding noise coming from a seized bearing.
Seized compressor clutch
The clutch that engages and disengages the power from the engine to the compressor can break or seize with heavy wear. This can keep the compressor switched off, even if the system has been switched on, and vice versa. While replacing the clutch is sometimes an option, compressor replacement is often the more efficient solution.
Why is A/C compressor replacement important?
The A/C compressor is the heart of your vehicle’s air conditioning system. As it is always cycled on and off, its mechanical parts will eventually wear out. Failure to keep up with regular servicing of your air conditioning system increases the possibility of compressor damage.
By ignoring the signs of a bad compressor, your drives will be less comfortable. It may even put your passengers at risk of heatstroke, especially during the hot summer months.
Make your search for a replacement A/C compressor easier by using our website’s search tab. Simply plug in your vehicle’s correct year, make, and model to browse through our vast selection of applicable parts.
What to consider when picking an A/C compressor
First, you should determine if your automobile uses R12 or R134a. The majority of vehicles that were manufactured in the early 90s and beyond use R134a, instead of the older and less earth-friendly R12. So, figure out which kind of system you have, because the mineral oil that is used in R12 cannot be used with R134a.
You should also check an automotive parts database to know the specific A/C compressor model that you need for your car.
When you finally know if your air conditioning system uses R12 or R134a and the exact A/C compressor model required in your vehicle, then you are now in a better position to select the right compressor for your automobile's A/C.
How much does an A/C compressor cost?
The cost of an A/C compressor will vary depending on your vehicle’s specific year, make, and model. OE replacement A/C compressors will typically cost you anywhere between $250 to $3,000. These are available for sale individually or as part of a kit.
In the case of these compressors, replacement is often better than attempting a repair. It is strongly recommended to have this part installed by a licensed mechanic. Chemical refrigerants may pose environmental and health risks in case of an accidental leak. To ensure proper fitting and replacement, it is best to consult a professional.
How to Install a New A/C Compressor
Note: These are general instructions for all types of automobiles.
Difficulty Level: Moderate
- New AC Compressor
- New O-rings
- A/C Machine
- Safety Glasses
Step 1: Lift the hood of your automobile and find your existing car AC compressor.
Step 2: Take the A/C belt out of the A/C compressor pulley.
Step 3: Clear the A/C system with the use of a refrigerant recovery machine.
Step 4: Detach the negative battery cable.
Step 5: Take out the bolt that holds refrigerant lines in the A/C compressor. Check A/C lines to see if they are dirty. When you see that there is too much dirt in them, you need to clean the A/C system.
Step 6: Detach all electrical connectors from your old A/C compressor.
Step 7: Take out the A/C connections and the bolts that keep your old A/C compressor in place. After that, you can now remove your existing A/C compressor.
Step 8: Put in your new A/C compressor.
Step 9: Secure your new A/C compressor by tightening the bolts that keep it in place.
Step 10: Connect all the electrical connectors to your new A/C compressor.
Step 11: Get the new O-rings to replace the old ones. Put the refrigerant lines and A/C belt back in the system.
Step 12: Get the negative battery cable connected to the A/C system again.
Step 13: Expel the air in the A/C system using an A/C servicing machine.
Step 14: Get hold of a vacuum on the system and pull it to see if there are leaks.
Step 15: If the A/C system holds the vacuum, charge it with an A/C servicing machine.
Step 16: Have a look at the A/C system sticker that is located under the hood to know the right amount and type of refrigerant and oil in the system.
Step 17: Place a thermometer in the middle of the A/C register.
Step 18: Turn your A/C system on while the engine is running to see if cool air is already going out of the air duct.
Step 19: If the thermometer reads between 30 and 36 degrees, then your A/C system is working correctly. You may also notice that your electric radiator fan and compressor clutch are cycling on and off in relation to the air temperature outside.