Panasonic CU-KS18NKU Technical & Service Manual page 116

(5) With the vacuum pump still running, close the "Lo"
knob of the manifold valve. Then stop the vacuum
pump.
(6) With the hex wrench, turn the valve stem on the
narrow tube service valve counter-clockwise by
90 degrees (1/4 turn) for 10 seconds, and then turn
the stem clockwise to close it again. (Fig. 58)
Be sure to completely insert
CAUTION
the hex wrench before
attempting to turn the valve.
(7) Leak test all joints at the tubing (both indoor and out-
doors) with soapy water. Bubbles indicate a leak. Tight-
en the joint more when leaks, then check if there is no
leak. Be sure to wipe off the soap with a clean cloth.
(8) With the hex wrench, turn the wide tube service
valve stem counter-clockwise to fully open the valve.
(9) Turn the narrow tube service valve stem counter-
clockwise to fully open the valve.
(10) Loosen the vacuum hose connected to the wide
tube service port slightly to release the pressure.
Then, remove the hose.
This may cause the refriger-
CAUTION
ant gas to leak. In order to
avoid this, take off the hose
quickly.
(11) Fasten the valve cap on the wide tube service port
securely with an adjustable wrench or box wrench.
Next, mount the valve cap on the service valve and
tighten it to 170 lbs·in (200 kgf·cm) with a torque
wrench. This process is very important to prevent
gas from leaking from the system.
(12) Test run the air conditioner. (See next page.)
(13) While the air conditioner is running, apply liquid
soap to check for any gas leaks around the service
valves or caps.
(14) If there is no leakage, stop the air conditioner.
(15) Wipe off the soap on the tubing.
This completes air purging with a vacuum pump and the
air conditioner is ready for actual operation.
90° (1/4 turn)
Vacuum hose to manifold valve
24
Narrow tube
Hex wrench
Wide tube
Valve cap
Fig. 58