Introducing Car Air Conditioning Compressor

The power unit of the air-conditioning system is the compressor that puts the refrigerant under high pressure before it moves into the condenser, where it gets converted from gas to a liquid.

If you want the air-conditioning system to provide peak performance, then a properly functioning compressor is essential. The A/C compressor is driven by an engine-accessory belt in most cars. The compressor will not function at full strength if the belt slips or is worn out. The refrigerant may also leak from the compressor, which might result in less air entering into the interior. Cold air also will not enter the system leading to the failure of internal parts.

AC problems do not always occur due to low refrigerant. It is also caused because of issues with system parts, like compressors, etc.

There are three types of Air Conditioning Compressor that differ how they exchange air between the AC system and the car’s interior.

1. Rotary Compressors - They compress and transfer refrigerant gas with the help of a roller/cylinder mechanism. The roller is divided in two by a spring-mounted blade that rotates inside a cylinder compartment and that’s how the refrigerant is compressed. Besides this, the blade will create two sealed-off areas within the cylinder. A variable pressure will develop on both sides of the blade as the roller rotates inside the cylinder. The compressed cooled gas will move out of the cylinder as pressure builds up on one side.
2. Scroll Compressors - A scroll compressor comprises two spiral disks and each has different heights. The shorter disk is placed inside the taller one. The short disk will compress the refrigerant gas by rotating inside the taller one and the tall disk will remain in one place. Sealed off areas will be created inside the tall disk when the disk rotates and has varying degrees of pressure. The refrigerant will get trapped inside the sealed-off areas when it suctions into the scroll. The gas will move towards the center of the scroll when the short disk rotates. This is how the gas gets compressed. Compressed cooled air will move out of the scroll through an exit along the tall disk wall.
3. Variable Displacement Compressors - The reciprocating compressor is also known as the variable displacement compressor. It compresses and transfers the refrigerant gas with the help of a piston/cylinder mechanism. A varying pressure is created by the upward/downward motion of the piston that works to push the refrigerant gas into the cylinder, compresses it, and pushes out the resulting cool air out into the car's interior. The pressure variations work to open and close the intake, as well as an exhaust valve.

Here is the working of car air conditioning compressor:

The workhorse of the air conditioning system is the compressor that is powered by a drive belt that is fixed to the crankshaft of the engine. When you turn on the AC system, the compressor will pump the refrigerant vapor under high pressure into the condenser. The condenser will alter the high-pressure refrigerant vapour to liquid and it moves to the receiver dryer. If there is any moisture that is leaked into the refrigerant, it gets removed. The pressurized refrigerant will flow from the receiver-drier to the expansion valve. It also takes away the pressure from the liquid refrigerant. The cold low-pressure refrigerant will vaporize and absorb heat from the air when it is passed into the evaporator, and the cold air is circulated when the blower fan pushes air over the outside of the evaporator. To start another refrigeration cycle, the compressor will draw in low-pressure refrigerant vapor. The refrigeration cycle will run continuously, and be controlled by the expansion valve setting. Though the process is simple, every AC system works on the same principle.

Want to know some common car air conditioning compressor problems? In that case, all you have to do is have a look below:

• The common cause of compressor failure is the loss of lubrication. This happens when the refrigerant starts leaking in the system and the oil will escape. If the lubricant is lost because of leakage or contamination, the compressor will not last for a longer time. The leakage points are hose and pipe connections, the evaporator, the condenser, and the compressor shaft seal. To find the leak, you can use an electronic leak detector or dye to repair them.

• The oil will circulate along with the refrigerant. The compressor may run dry or seize if the tube or expansion valve is clogged.

• You will have to replace the compressor if it is leaky, making noise, or not functioning properly. Compressors are noisy, but several times, the loud noise can be because of the dirt present in the system. Another symptom of a faulty compressor is the metallic and bearing noises.

• If the unit is leaking internally or not producing enough pressure, then you will need a new compressor. Even though there is a full charge on the refrigerant, a worn-out compressor cannot produce normal operating pressure.

• Poor cooling can take place because of a defective compressor. And so do not change the compressor unless other possibilities are ruled out like less refrigerant charge, more oil in the system, contamination of air, blocked condenser, plugged orifice tube, inoperative electric cooling fan, etc.

• Compressor operation can be affected by sensors in vehicles with automatic temperature control systems. Some vehicles have an A/C pressure transducer to look after the refrigerant pressure and to put off the compressor if pressure is too high. The compressor temperature sensor will turn off the compressor if it’s hot.

Usually, when the compressor is faulty, it shows a few signs which alert the driver that there is some problem in the system. If there are any issues with the compressor, then the entire AC system might be affected.

1. Cabin temperatures higher than normal- The first indication of a compressor having issues is that the AC will no longer blow cold air. If the compressor is faulty, then it cannot regulate the refrigerant flow properly in the AC system and hence the system will not function properly. 

2. Loud noises when the compressor is running- Another potential symptom of a failing AC compressor is the loud noise that is heard when you switch on the AC. The compressor will start producing various noises if the interior components break, or if the compressor’s internal bearings are defective or seized. A high-pitched squealing or grinding sound will be produced if the compressor is leaking or worn out. You will hear a grinding noise or a noticeable belt squeal if the compressor has seized bearing or is seized. Rather than trying to repair it is best to replace the compressor as it is easy. 

3. The compressor clutch is not moving- An Immovable clutch is another sign of a problematic compressor. The pulley will engage and disengage from engine power with the help of the clutch on the compressor. This will make the compressor turn only when it needs to. The clutch gets seized, which makes the compressor get activated completely. It can also break, so the engine power will not be received by the compressor. Change the clutch, but changing the entire compressor turns out to be most efficient.

If you were searching for top-quality tools to repair your Air Conditioning Compressor, then your search is over. Have a look at some tools which you might need to repair your Air Conditioning Compressor:

• Jack and jack stands
• Protective gloves
• Repair manuals
• Safety glasses
• Wrench

Have a look at some top brands for Air Conditioning Compressor:

• Four Seasons Air Conditioning Compressor
• Spectra Premium Industries Air Conditioning Compressor
• Denso Air Conditioning Compressor
• Cooling Depot Air Conditioning Compressor
• Federated/Four Seasons Air Conditioning Compressor

It is always good to learn more! That is the reason we are here to help you out in gaining more knowledge about car Air Conditioning Compressors. Here are some Air Conditioning Compressor-related parts which would help you to understand it in a better way.

• Compressor
• Drier or Accumulator

The cost of replacing an Air Conditioning Compressor varies greatly based on the application, the brand of the Air Conditioning Compressor, and who performs the service. All you have to do is order a replacement for your broken Air Conditioning Compressor online, then drop your car off at the mechanic and pick it up a few days later. Just make sure the mechanic is experienced and has a good reputation. The average cost of an AC compressor unit lies between $195 to $736 for the part itself, whereas the cost for parts and labor can range between $376 to $986.

Here are a few steps how you should change the Air Conditioning Compressor.

Part 1 of 2: Locate the Compressor

Step 1

Find the location of the A/C compressor. You can find it at the front of the engine along with other belt-driven accessories.

Step 2

Remove the refrigerant before you service the AC system. Only professionals perform such action with the help of an evacuation machine.

Part 2 of 2 Remove the Compressor:

Step 1

Find the location of the drive belt tensioner. If you find it difficult to identify the location, check the belt routing diagram. You can find it on the decal placed in the engine compartment, or the vehicle repair manual.

Step 2

Now you must rotate the tensioner. With the help of a socket or wrench, slide the automatic tensioner far away from the belt. The rotation can be clockwise or anti-clockwise, depending on the vehicle and belt routing.

Step 3

Now take away the belt from the pulleys. As you hold the tensioner away from the belt, slide the belt away from the pulleys.

Step 4

Detach the electrical connectors from the compressor. It is easy to pull them off.

Step 5

Separate pressure hoses from the compressor. With the help of a ratchet or wrench, and detach the pressure hoses from the compressor. Plug them to prevent system contamination.

Step 6

The compressor mounting bolts have to be removed with the help of a ratchet or wrench.

Step 7

Be careful when you remove the compressor from the vehicle as it might be heavy.

Step 8

Now fix the new one. Make sure that it is like the old one. Remove the dust caps from the new one and add a recommended lubricant to the new compressor, for instance, PAG oil. Few compressors have oil installed in them already. So read the instructions carefully.

Step 9

Now change the pressure line O-rings from the AC pressure lines by using a small screwdriver.

Step 10

Fix the new compressor into the vehicle and straighten it with the help of mounting holes.

Step 11

Fix the mounting bolts and tighten them again.

Step 12

Fix the lines and tighten down the bolts again.

Step 13

Install the electrical connectors again similarly.

Step 14

Fix the belt on the pulleys by following the diagram to make sure that the belt is correctly routed.

Step 15

Now install the new belt. You will have to either push or pull the tensioner so that the belt is properly seated on the pulleys. Once the belt is fixed, release the tensioner and take off your tool.