Delphi Compressors: OE Quality and Efficiency


How to Replace a Compressor

Video on how to replace a compressor

Why Delphi?

No extra parts to purchase or stock. Sealing washers included with all compressors (when applicable). Our compressors are leak tested to one pound of refrigerant in 40 years using sophisticated mass spectrometer leak test equipment.

Did You Know?

Delphi covers more than 3,400 applications. Delphi supplies compressors for 1989 to present applications. Delphi provides HVAC components to eight of the top 11 OEM global manufacturers. The majority of Delphi compressors are made in North America. Delphi manufactured the first underhood air conditioning system in 1954.

SP Compressors:

  • Maximized performance and high efficiency due to its lightweight design.
  • Quiet and reliable as a result of its smooth pumping operation.
  • Durable, lightweight and compact piston design.

Compact Variable Compressors (CVC):

  • Founded on the swash plate design used on
  • Delphi V5 and V7 compressors.
  • Improved air conditioning performance and fuel economy due to its smooth, continuous operation without clutch cycling.
  • Meets vehicle air conditioning demand with adjustable displacement capability.

V5 and V7 Compressors:

  • Improved air conditioning performance and fuel economy because of its smooth, continuous operation without clutch cycling.
  • Meets vehicle air conditioning demand with its adjustable displacement capability.
  • V7 compressors feature increased capacity, reduced noise and minimized vibration.
  • V7 compressors are compatible with R-134a systems.
  • V5 compressors are compatible with R-12 and R-134a systems.

H6 Compressors:

  • Extremely efficient and lightweight.
  • Improved OE design for increased performance and reliability.

Why and When to Change the Compressor

Causes of Compressor Failures

  • Lack or excess of refrigerant oils
  • Internal corrosion
  • Lack of servicing (regular changing of receiver drier)
  • Circuit blocked – receiver drier clogged and/or expansion valve blocked
  • Incorrect or no flushing of system when fitting new compressor
  • Electrical problem in the clutch

Effects of Faulty Compressors

  • A/C system does not operate at all
  • Potentially result in damage to other A/C components

How to Help Prevent Compressor Failures

Best Practice # 1: Compressor Preparation Prior to Operation

You wouldn't expect a rebuilt engine to run properly if it wasn't pre-lubed or only had one quart of oil in the crankcase on initial startup. The same is true for a compressor. In order for the compressor to operate correctly on startup, it must have the accurate amount of oil inside and be turned over, by hand, using the right compressor turning tool, so all the components inside are “prelubed.”

Failure to complete this prelubrication process prior to compressor operation can lead to noise complaints and premature failure. There are two types of compressors – with oil and without oil. Compressors with oil (prelubed) need to have the new oil drained, and the correct oil amount and type reinstalled. Dry compressors, or compressors without oil, need to have the correct amount and type of oil added prior to compressor operation. Regardless of compressor type, instructions included demonstrate how to correctly lubricate and rotate the compressor prior to operation.

Best Practice #2: Flush the System

When flushing the A/C system with chemicals, ensure no residual flush is left behind. If there is, it could dilute and contaminate the compressor lubricant leading to compressor noise and premature failure.

If you are flushing an A/C system, it is critical you use the approved OEM equipment, flushes and procedures to help minimize concerns with potential residual flush.

This is a destroyed reciprocating assembly from a compressor that failed due to lack of lubrication. The lubricant removed from the compressor was thin (had poor viscosity) and had a chemical flush odor.

Best Practice #3: Use Correct Lubrication

Seems simple… use the lubricant type recommended in the instructions that come with the new compressor. Unfortunately compressors fail every day by having the wrong lubricant.

Without the correct lubrication, the compressor has little or no chance of long-term stability. There are a number of lubricant types on the market depending on the A/C system. PAG oil is the most common. It is important that high quality PAG oil be used and the technician follows the directions included with the new compressor so the correct type and amount of oil is utilized, and in the proper location.

Ester oils are also available, but should not be used as they can break down under high heat conditions resulting in lubrication and compressor failures.

This is the inside of a failed compressor, showing lubrication that has become a thick, black sludge. Ester oils, which are not recommended for use in Delphi compressors, can experience thermal breakdown in high heat conditions, and form sludge like this.

When lubricating compressors with a crank case plug, be sure to remove and install all lubrication through this opening so the oil can get directly to the rotating assembly inside the compressor.

It’s All a Balancing Act

Why Oil Balancing is Critical When Replacing a Compressor

Tech Tip

When installing a new service compressor on a vehicle it is important to make sure the compressor is oil balanced correctly with the correct type and amount of lubricant. The purpose of oil balancing is to make sure the amount of oil in the air conditioning system remains at the correct level.

The first thing to consider when performing the process is the amount of oil contained in the replacement compressor. This can vary from a full charge of oil (8 oz. (236 mL)), to a half charge of oil or no oil at all. If oil is contained in the replacement compressor it will have to be removed and reinstalled in the correct amount to properly balance the system.



Follow The Instructions

When performing a compressor oil balance, always follow the instructions provided with the compressor or in the vehicle service manual to know how much oil to add to the compressor prior to vehicle installation.



Add Correct Amount

Most times oil balancing involves draining and measuring the oil from the failed compressor, followed by adding a specific volume of new oil to the replacement compressor.

The amount of oil to be added to the compressor is specified by the compressor manufacturer. 



Oil Viscosity

In addition to adding the correct amount of oil to a replacement compressor, keep in mind oil viscosity.

Use the viscosity of oil recommended by the compressor manufacturer. If the compressor requires heavier weight oil, such as PAG 150, but PAG 46, which is a lighter weight, is used, the result could be noisy compressor operation and premature wear.



Rotate The Compressor Clutch

After adding the oil to the compressor, a good service tip is to rotate the compressor clutch at least four turns prior to compressor installation. This serves two purposes. Rotating the clutch circulates oil through the compressor, which reduces the potential of compressor damage due to dry bearings, and it reduces initial torque when the clutch is first engaged. By design some compressors have a high initial torque. If the torque is high when the compressor is engaged, the torque that is created could cause the compressor drive belt to snap or cause the engine to stall.

Rotating the compressor clutch is usually done by hand or with a spanner wrench. Another option to the spanner wrench is the compressor turning tool. On direct drive compressors, the pulley and clutch are one and the same. 



The Turning Tool

The turning tool performs the same function as the spanner wrench, but it is installed on the threaded hub of the clutch.

After the turning tool is installed, use a wrench to turn the tool and clutch. The turning tool can be used on some clutches that cannot accept a spanner wrench because of clutch design, or where a solid grip by the spanner wrench cannot be achieved.

The turning tool can also be used in place of the spanner wrench, providing an easier method of clutch rotation, and it can be done off or on the vehicle.


Never Use A Socket

Never use a socket on the shaft nut or bolt to rotate the clutch.

Doing so may affect the air gap between the clutch driver and compressor pulley, resulting in compressor issues.


The Hybrid Compressor: Know the Difference

Compressor Differences

HVAC differs from one hybrid to the other and some systems, such as Honda & Prius 2001-2003, have used a scroll compressor which can be powered via belt when the engine is running or electrically when the engine is off. Most of the newer hybrids have changed to an inverter compressor which is a high voltage electrical motor. The motor runs on high voltage AC supplied by the A/C inverter located in the inverter or affixed to the AC compressor itself so compressor operation does not depend on the engine.

The electric compressor consists of a spirally wound fixed scroll and variable scroll with a brushless motor. These systems use a special high insulation for compressor lubrication. The compressors are a wet sump with the armature submerged in oil for lubrication and cooling. Oil based florescent dye should not be added to electrical compressor systems due to electrical conductivity. 

Leak detection dye, when used in the proper quantity, will not harm air conditioning components or those working with it. If a vehicle was manufactured with leak detection dye, adding more is not necessary unless prior air conditioning system flushing or multiple refrigerant component replacement caused the dye to be removed from the system.


Leak Detection Dye

There is a specific dye for hybrid electric vehicles, which use R-134a in the air conditioning system equipped with an electric compressor. Hybrid electric vehicle leak detection dye is polyolester based and is specific to hybrid electric vehicles. 

The R-134a leak dye used for non-hybrid electric vehicles uses PAG oil which is hygroscopic. Using it in a hybrid vehicle, even in the smallest amount, can create an air conditioning compressor failure. The oil in the dye breaks down the insulating properties of the windings on the electric motor portion of the compressor. The windings on air conditioning compressor are immersed in compressor oil and ester oil is used to protect the insulation on the windings to prevent electrical leakage. The addition of PAG oil into a hybrid air conditioning system designed for ester oil may result in an air conditioning system malfunction.

Additionally, in hybrid vehicles with an electric compressor, when a dye containing a lubricant other than ester oil is added to the air conditioning system, it contaminates the air conditioning system. Flushing the system must be performed to remove the dye. In fact, because of the contamination concern with dye, Honda does not approve its use in hybrid vehicles. Toyota does not recommend dye for any of their air conditioning systems.

Ask the Right Questions During Compressor Diagnosis


Tech Tip

Ask the following questions below during diagnosis, as they could indicate the compressor or clutch overheated due to a system-related problem.

  • Are there indications of over cycling of the compressor clutch? Is the paint on the clutch face burnt or melted?
  • Does the clutch show evidence of overheating due to slippage?
  • Is there a blue-black appearance to the clutch face due to overheating?
  • Are rubber cushions on the clutch melted?
  • Are the labels on the compressor body bubbled or melted?

We also recommend inspecting the clutch oil connector for damage from a misaligned drive belt, checking for low voltage at the clutch electrical connector to see if there is a vehicle wiring issue and checking the compressor port for evidence of contamination and debris.

Compressors Do’s and Don’ts

Tech Tips for Compressors


Oil balance the compressor according to the instructions provided with the compressor.

An oil balance will ensure the compressor has the correct amount of compressor lubricant for proper compressor operation.


Leave protective shipping cap in place until assembly of refrigerant lines.

Prevent loss of lubricant and contamination or unit, and absorption of moisture by PAG lubricant. (PAG readily absorbs moisture from the atmosphere.)


Store compressors in the shipping box until ready for installation.

Damage to the clutch, electrical terminals and pressure switches will result if the compressor is handled and/or stored improperly.



Use correct torque control tools:

  • To attach refrigerant lines at the compressor.
  • When installing compressor brackets.
  • When securing the compressor to the engine.  Excessive torque may strip threads in the compressor housing. Under torque will result in loose, damages, or a noisy compressor.



Hand start all bolts and nuts securing the compressor to the engine and for all braces and brackets.

This will prevent the steel bolt and nut from stripping the threads in the compressor housing or mounting points.


Hand start bolts securing the suction discharge hose set to the compressor. This is a critical requirement.

This will prevent the steel bolt from stripping the threads or cross threading in the aluminum compressor housing.

Do Not

Set the compressor on either end, stack or subject them to shock at any time. Keep the compressor in a horizontal position.  

Damage to the clutch, electrical terminals and pressure switches will result if assemblies are handled and/or stored improperly.

Do Not

Lubricate seal washers prior to attaching refrigerant lines to the compressor.

Seal washer design does not require lubrication to affect a leak free joint.


Replace protective shipping cap on suspect or defective compressors.

Uncapped compressors are subject to leak lubricant, become damaged, or absorb moisture, making subsequent analysis difficult or impossible for the part supplier.