MAHLE RTI RRC770A - Manual (Page 15)

Page 12
EXAMPLE: The level of liquid visible in the RRC770 Internal Cylinder Sight Glass is 7.4
lbs. and the A/C system capacity is 3.2 lbs. The following calculation results:
(7.4) - (3.2) = 4.2
Therefore, the sliding indicator should be set at 4.2 lbs. in this example. When the
liquid level lowers to the 4.2 lb. mark, a charge of 3.2 lbs. will have been delivered.
NOTE... The Sight Glass on the Charging Cylinder has markings for both R12
and R134a. Always use the correct scale for accurate charging.
7. Open Red Hose Valve. Do not start the Vehicle's Engine. Refrigerant will flow into
the high side of the A/C System. Closely monitor the liquid level as it lowers in the
Internal Cylinder Sight Glass.
8. Close Red Hose Valve as soon as the refrigerant level drops to the sliding indicator.
9. Close High Gauge Valve.
10. Turn Main Power Switch to Off.
Evacuate the hoses per the preceding section "Hose Evacuation Procedure"
The vehicle can now be started and the A/C system checked by monitoring Gauge
pressures.
Close all valves before disconnecting hoses.
NOTE: The preceding is the recommended method of charging with the RRC770.
Some vehicle manufacturers may specify connecting only to the Low Side of
the A/C System. Always follow their procedures. The above instructions
would have to be modified accordingly.