Tag: AC compressor

How to add oil to air conditioning compressor ?

How to add oil to air conditioning compressor ?



How to add oil to air conditioning compressor ?


Oil in the A/C system is essential, primarily to lubricate moving parts, i.e., the compressor. It also enables heat to travel and dissipate from the compressor. As with refrigerant, oil in the A/C system must keep its chemical stability.


Insufficient lubrication due to the wrong type of oil and viscosity is the second most frequent reason for A/C compressor damage and failure.


Distinct types of a/c oil like PAG,POE or mineral oils with a different viscosity do not mix, leading to poor lubrication, damaged seals and increased automotive air conditioning compressor wear


The use of the wrong type of oil could result in the hvac compressor’s piston rubbing against the cylinder surface. If the oil is too thick, it is unable to properly lubricate the tight space between the cylinder wall and the piston. Wrong oil viscosity can result in more internal friction, leading to an increase in compressor temperature and inevitably compressor damage.


Blending or mixing of diverse types of oils may result in a new different type and oil viscosity. This oil contamination build-up to the point where it can block the flow of refrigerant and oil, leading to poor lubrication and seizure of the compressor and major system failure.



Refrigerant moving oil and cooling down the A/C Compressor


it is extremely important that the engine not be run on a vehicle with a clutch less compressor if there is no refrigerant in the A/C system. This is because the compressor depends on refrigerant to carry lubricant inside of it.



How much oil should I add after a/c compressor replacement ?


After the refrigerant system has been charged and ran at the factory, the refrigerant oil in the A/C compressor is dispersed throughout the refrigerant system. The A/C receiver/drier, A/C evaporator, A/C condenser and the A/C compressor will each keep a significant amount of the needed refrigerant oil.

The refrigerant oil level in a new A/C compressor must first be adjusted prior to compressor installation.


Oil balancing the a/c system:

  1. Measure the oil recovered from the system by recovery/recycling/recharging station.
  2. Drain and measure the oil left in the old compressor using a beaker.
  3. Drain the new compressor and refill it with the same amount of oil removed from the system and old compressor .
  4. For Example :if 2 oz of oil are recovered from the system and 2 oz of oil was drained from the old a/c compressor, drain the new replacement a/c compressor and then add 4oz of the proper oil type and viscosity to the compressor before installation.



Installing the ac Compressor without balancing the oil in the system, gives a considerable risk of liquid lock, due to too much oil in the A/C system! When adding oil to the ac compressor in your car one out of two methods could be used and the right one will depend on the type of compressor. Oil could be added through the ac compressor oil service port or through the low side or intake of the compressor. Always add oil through the oil service port if it comes with one or compressor damage may result.


Most reclaim/recycling recharging stations will measure the lubricant being removed during recovery. This amount of lubricant should be added back into the system after the repairs are done.


How could the oil in my car’s A/C system be low?


Leaking automotive air conditioning systems will leak out refrigerant and the oil that resides inside of the compressor.

Refrigerant oil must be added when an A/C condenser, A/C receiver/drier or A/C evaporator is replaced

Refrigerant oil loss will be evident at the leak point by the presence of a wet, shiny surface around the leak.


Do you need assistance balancing the a/c compressor oil ?

Call today ! Our ASE certified mechanics do auto ac compressor repairs on site.






What causes an ac compressor to lock up

What causes an ac compressor to lock up

Inaccurate refrigerant(freon) charges increase the chances of auto ac compressor lock up. Modern auto a/c systems require super accurate charging. Being off as little as 2 ounces can cause problems.R-134a and R-1234yf ac system tolerances require charge rates that must remain or should be charged within +/- 5% of OEM recommendation. SAE J2788 requires charge accuracy of +/- one-half ounce.

Attempting to charge by cans is History !!

Car ac compressor lock up due to improper compressor lubrication.

Refrigerant moves the oil inside the ac system and helps to cool down the ac compressor. An undercharge or overcharge refrigerant condition will increase the air conditioning compressor temperature and a change in oil viscosity and lubrication characteristics. Most compressor lock ups are the result of a lubrication problem.

AC compressors lock up due to ac system contamination

Auto ac compressor damage may occur because of system contamination. Anything more than the correct type of freon and oil is a contaminant. The use of sealers to fix small refrigerant leaks will cause oil and refrigerant contamination and ultimately ac compressor lock up. Sealer can’t be removed from the A/C systems. The contaminated components must be replaced.

The use of excessive Dye to help finding leaks in the ac system could create a contamination problem as well, increasing the normal working pressure of the ac compressor and the overall efficiency of the air conditioning system.

Improperly replacing any component in the automotive air conditioning system where the system must be opened for replacement of the damaged part and not evacuating the system before recharging it with the proper amount and type of refrigerant will contaminate the ac system with air. Air and moisture inside the system will create excessively high operating pressures and temperatures and eventually could lead to a compressor lock up.

Inefficient ac condensers and air conditioning compressor lock up

Debris on the condenser will affect the desuperheat, condensation and subcooling processes happening in the auto ac condenser.AC condenser with bent or missing fins will be unable to efficiently operate. An inefficient ac condenser will cause an auto ac compressor to lock up.

Low Refrigerant charge and electronically controlled compressor lock up ?

The car engines in vehicles with the clutchless compressors should not be run without refrigerant in the A/C system. Without refrigerant to move the oil, the auto ac compressor may not be properly lubricated and compressor lock up may result.

Do you need assistance inspecting the state of your ac compressor in your vehicle?

Call Us today ! We have automotive ac specialists near you.

Can i drive my car with a bad ac compressor

Can I drive my car with a bad A/C compressor?

Can I drive my car with a bad A/C compressor?

Driving the car with a locked up a/c compressor may damage the accessory drive belt. A bad compressor could affect the engine in your car. If your compressor’s pulley bearing goes bad, your engine can stall due to the stuck compressor or the serpentine belt may break affecting all the accessories moved by the serpentine belt.

Types of A/C compressors and compressor lock up.

Clutch-less variable displacement compressors have extra protection in case the compressor seizes. In the event a compressor failure occurs the bridges on the clutch assembly will break and only the pulley will keep running, allowing the engine to keep running.

Do you need to get your car’s a/c compressor checked up ?

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auto ac repair near me

Thermal switches are used on both the low and high side of AC systems. A Thermal switch may be connected in series with the compressor clutch.

A/C compressor cycling control .

A thermostatic switch de-energizes the clutch and stops the compressor to keep the evaporator from freezing up. When the temperature of the evaporator approaches the freezing point (or the low setting of the switch), the thermostatic switch opens the circuit and disengages the compressor clutch. The compressor remains inoperative until the evaporator temperature rises to the preset temperature, at which time the switch closes and compressor operation resumes.

A/C Compressor temperature control.

A thermal limit switch may be mounted on or near the compressor and is used to stop compressor operation before the temperature of the compressor reaches a point of damage.


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Do new car A/C compressors come with oil?


Does the new car ac compressor contain oil?

Many auto ac compressor manufacturers list the oil amount on the label usually on the hvac compressor itself, but not all. Some may show it on the under hood sticker in the engine compartment. The best  and most reliable way to determine the exact amount of oil in the new car ac compressor is to drain the new ac compressor and measure the amount of oil if any,   inside.

Do you need assistance balancing the oil in your car ac compressor ?

Call Us today ! One of our  ASE certified car ac mechanics  will come to your home or office. We have car ac mechanics near you.