Air Conditioning System: Evacuating

WARNING: This page is about a different car, the 2003 Lexus LS 430. However, it is still accessible from the selected car via links, so may be relevant.

CONNECT QUICK DISCONNECT ADAPTER TO CHARGING HOSES
REMOVE CAPS FROM SERVICE VALVES ON REFRIGERANT LINES
SET ON MANIFOLD GAUGE SET
1. Close both hand valves of manifold gauge set.
2. Connect the quick disconnect adapters to the service valves.
  
  Fig 1: Installing Quick Disconnect Adapter & Charging Hose
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
EVACUATE AIR FROM REFRIGERATION SYSTEM
1. Connect the vacuum pump adapter to the vacuum pump.
  
  Fig 2: Connecting Vacuum Pump Adapter To Vacuum Pump
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Connect the center hose of the manifold gauge set to the vacuum pump adapter.
3. Open both the high and low hand valves and run the vacuum pump.
4. After 10 minutes or more, check that the low pressure gauge indicates 750 mm Hg (30 in. Hg) or more.
  HINT:
  
  If the reading is 750 mm Hg (30 in. Hg) or more, close both hand valves of manifold gauge set and stop the vacuum pump. Check the system for leaks and repair if necessary.
5. Close both the high and low hand valves and stop the vacuum pump.
6. Leave the system in this condition for 5 minutes or more and check that there is no gauge indicator.
  
  Fig 3: Connecting Manifold Gauge Set To High & Low Pressure Service Valve
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002