The purpose of oil balancing is to make sure the amount of oil in the A/C 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.
It’s also important to 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 lighter-weight, is used, the result could be noisy compressor operation and premature wear.
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. Rotating the clutch circulates oil through the compressor, which reduces the potential of compressor damage due to dry bearings, and it also reduces initial torque when the clutch is first engaged.
Rotating the compressor clutch is usually done by hand or with a spanner wrench. Another option is a compressor turning tool. On direct-drive compressors, the pulley and clutch are one and the same.
The turning tool performs the same function as the spanner wrench, but it’s 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 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.