Service manual
14
English
When reaming, hold the tube end downward and be sure
that no copper scraps fall into the tube. (Fig. 9)
(3) Remove the flare nut from the unit and be sure to mount
it on the copper tube.
(4) Make a flare at the end of copper tube with a flare tool.*
(Figs. 10 and 11) 
(*Use “RIDGID” or equivalent.)
A good flare should have the following characteristics:
G inside surface is glossy and smooth.
G edge is smooth.
G tapered sides are of uniform length.
3-5. Caution Before Connecting Tubes Tightly
a) Be sure to apply a sealing cap or water-proof tape to
prevent dust or water from getting into the tubes before
they are used.
b) Be sure to apply refrigerant lubricant to the matching 
surfaces of the flare and union before connecting them
together. This is effective for reducing gas leaks. 
(Fig. 12)
c) For proper connection, align the union tube and flare
tube straight with each other, then screw in the flare nut
lightly at first to obtain a smooth match. (Fig. 13)
3-6. Tubing Connections
a) Temporary connection:
Screw in 3 – 5 rotations by hand. (Fig.14)
b) To fasten the flare nuts, apply specified torque as:
Table 4
NOTE
NOTE
Reamer
Copper
tubing
Fig. 9
Flare tool
Flare nut
Copper 
tubing
Fig. 11
Fig. 10
Apply refrigerant 
lubricant here and here
Fig. 12
Flare nut
Union
Fig. 13
0 – 0.5 mm
If the special R410A 
flare tool is used:
1.2 mm
If the previous flare tool 
(clutch-type) is used:
Adjust so that the amount of tube 
protrusion is as shown in the figure.
Apply the provided labels 
to the indoor and outdoor 
unit tubing connectors to 
prevent errors in 
connections.
Service valve on 
narrow tube side
Service valve on 
wide tube side
A
B
C
D
Fig. 14
Tube Dia. Tightening Torque
6.35 mm 14 – 18 N·m (140 – 180 kgf · cm)
9.52 mm 34 – 42 N·m (340 – 420 kgf · cm)
12.70 mm 49 – 61 N·m (490 – 610 kgf · cm)
15.88 mm 68 – 82 N·m (680 – 820 kgf · cm)
07-336 AE4MI80AH_OU ENG 11/7/07 4:29 PM Page 14










