Charging, Oil Discharging and Refill Procedure

Subaru Air Conditioning Systems

Air

Charging

Charging the system is required after servicing, repair or replacement of system components, or to locate aioningleak when there is no refrigerant in the system. Follow the steps listed below to charge the system:

Condit• Leak detection of a pressurized system is required to locate an otherwise unidentifiable leak in a discharged system or when the system was dicharged/evacuated for repairs.

• The proper procedure is to:

- Connect the manifold gauges or ACR-4 to the system.

- Attach the center charging hose to the refrigerant source. - Charge the system initially with .5 -.75 lbs (0.226-0.34 kg).

Note: Refer to the appropriate model year Subaru Service Manual or air conditioning manufacturer’s instructions for charging details, pressures, and system capacities. Use an electronic leak detector such as a pump-style halogen dual-gas type.

-If a leak is detected, recover the remaining refrigerant and repair the leak.

-If no leak is detected, continue charging the system.

-When charging of the system has been completed, close the manifold gauge valves, and manually rotate the compressor several turns to distribute any trapped refrigerant oil before the clutch is engaged.

-Check again for refrigerant leaks with an approved leak detector.

-Conduct a performance test.

-Upon successful completion of the performance test, disconnect the high and low-pressure hoses from the service valves.

-Replace the valve caps to the service valves.

Charging/Leak Detection

Refrigerant is colorless and odorless. You must use a leak detector to locate a leak and determine the size of the problem.

Use of a halogen pump style electronic leak detector is recommended over other types of detectors. Electronic leak detectors usually buzz or squeal in the presence of refrigerant. Always follow the leak detector manufacturer’s instruc- tions for proper use. It is Subaru policy to not use flame-type detectors, because harmful gasses may be emitted when using these types of detectors.

Oil Discharging and Refill Procedure

Discharge the compressor oil when the quality of the refrigerant oil is unsatis- factory or for repair of the compressor. Turn the compressor upside down, and pour the oil out of the compressor. Most compressors drain oil from both the inlet and outlet ports. The DIESEL KIKI variable dis-

placement compressor drains (and fills) oil through a drain plug hole located in the center of the case. Always refer to the appropriate model year Subaru Service Manuals and the A/C manufacturer’s instructions. Be sure to record the amount of oil discharged.

End Wrench

The

Note: New compressors contain enough oil for a complete dry system. When replacing a new compressor on an existing system, the old compressor must be drained and the oil quantity measured. Then drain the new compressor and measure the amount of oil.

Refill the new compressor with the same quantity of oil as was removed from old compressor.

Oil Discharging

R-12, R-134A specifications

Subaru, a renowned automotive manufacturer, has made significant advancements in its air conditioning refrigerant technologies, particularly in its use of R-12 and R-134A. Understanding these refrigerants is crucial for enthusiasts and technicians alike, as they are integral to Subaru's climate control systems.

R-12, also known as dichlorodifluoromethane, was commonly used in automotive air conditioning systems until the late 20th century. It is a chlorofluorocarbon (CFC) that proved to be highly efficient in cooling systems, offering optimal performance in various conditions. However, environmental concerns over ozone depletion led to a phasedown of its use. Subaru vehicles produced before the early 1990s often utilized R-12, characterized by its stable properties and excellent thermodynamic performance. Despite its effectiveness, the negative environmental impact of R-12 has rendered it obsolete in modern automotive applications.

Adapting to these challenges, Subaru transitioned to R-134A, or tetrafluoroethane, in the 1990s. R-134A is a hydrofluorocarbon (HFC) that does not deplete the ozone layer, making it a more environmentally friendly alternative to R-12. This transition coincided with Subaru's commitment to sustainability and compliance with international regulations. R-134A boasts several advantages, including lower global warming potential and improved efficiency in cooling performance. Its thermodynamic properties provide effective heat absorption, ensuring that Subaru drivers can rely on consistent climate control, regardless of external temperatures.

Subaru has integrated R-134A into its vehicle technology without compromising performance. Newer models utilize advanced HVAC systems that maximize refrigerant efficiency while maintaining comfort. Features such as variable compressor speed control enhance overall system performance, allowing for quicker cooling response and reduced energy consumption. Additionally, Subaru employs meticulous system designs to minimize refrigerant leakage, further supporting environmental initiatives.

The transition from R-12 to R-134A exemplifies Subaru's responsiveness to both performance and environmental concerns. As regulations continue to evolve, it's expected that Subaru will continue to innovate in refrigerant technology, prioritizing sustainability while delivering reliable and efficient climate control for its drivers. As vehicle technology advances, it's clear that Subaru remains committed to adapting its systems for a cleaner, more efficient future.