AC–4 AIR CONDITIONING SYSTEM – GENERAL DESCRIPTION SERVICE TOOLS FOR HFC134a AIR CONDITIONING When servicing HFC134a air conditioning systems always use the HFC134a dedicated manifold gauges, gas leak detector and vacuum pump adaptor. 1. USE MANIFOLD GAUGES FOR HFC134a AIR CONDITIONING Always use HFC134a dedicated manifold gauges to prevent CFC 12 and CFC 12 compressor oil contaminating the HFC134a system. Quick Link Connector Quick Link Connector N04351 2. USE HFC134a GAS LEAK DETECTOR Similarly, always use an HFC134a dedicated leak detector. The CFC12 leak detector is not sufficiently sensitive. N04144 3. USE VACUUM PUMP ADAPTER By connecting a vacuum pump adapter, the vacuum pump can be used for both HFC134a and CFC12 air conditioning systems. The vacuum pump adaptor has an internal magnetic valve. When evacuation is completed and the vacuum pump switch is turned off, the magnetic valve opens allowing the introduction atmospheric air into the manifold gauges to prevent the back flow of oil from the vacuum pump into the gauge hose. CAUTION: Be sure to turn off the manifold gauge valve immediately after evacuating the system. Then you may switch off the vacuum pump. If this order is reversed, the line will be temporarily open to atmosphere. Vacuum Pump Adapter Plug Cap R12 Connection Port R134a Connection Port Vacuum Pump N04136