MAINTENANCE AND SERVICING
Form 169552 / 169554 / 169555
111
Revision A
7.3.1.3 Flare Type Hydraulic Fittings
a. Check flare and flare seat for defects that might
cause leakage.
b. Align tube with fitting before tightening.
c. Lubricate connection, and hand-tighten swivel
nut until snug.
d. To prevent twisting the tube(s), use two
wrenches. Place one wrench on the connector
body, and with the second, tighten the swivel nut
to the torque shown.
SAE
NO.
TUBE
SIZE
O.D.
(in.)
THD
SIZE
(in.)
NUT
SIZE
ACROSS
FLATS
(in.)
TORQUE
VALUE*
RECOMMENDED
TURNS TO
TIGHTEN
(AFTER FINGER
TIGHTENING)
ft·lbf N·m Flats
Turns
3
3/16
3/8
7/16
6
8
1
1/6
4
1/4
7/16
9/16
9
12
1
1/6
5
5/16
1/2
5/8
12
16
1
1/6
6
3/8
9/16
11/16
18
24
1
1/6
8
1/2
3/4
7/8
34
46
1
1/6
10
5/8
7/8
1
46
62
1
1/6
12
3/4
1-1/16
1-1/4
75
102
3/4
1/8
14
7/8
1-3/8
1-3/8
90
122
3/4
1/8
16
1
1-5/16
1-1/2
105 142
3/4
1/8
*
The torque values shown are based on lubricated connections
as in re-assembly.
7.3.1.4 O-Ring Boss (ORB) Hydraulic Fittings
a. Inspect O-ring and seat for dirt or obvious
defects.
b. On angle fittings, back off the lock nut until
washer (A) bottoms out at top of groove (B) in
fitting.
c. Hand-tighten fitting until back up washer (A) or
washer face (if straight fitting) bottoms on part
face (C), and O-ring is seated.
d. Position angle fittings by unscrewing no more
than one turn.
e. Tighten straight fittings to torque shown.
f. Tighten angle fittings to torque shown in the
following table, while holding body of fitting with
a wrench.
SAE
NO.
THD
SIZE
(in.)
NUT SIZE
ACROSS
FLATS
(in.)
TORQUE
VALUE*
RECOMMENDED
TURNS TO TIGHTEN
(AFTER FINGER
TIGHTENING)
ft·lbf
N·m
Flats
Turns
3
3/8
1/2
6
8
2
1/3
4
7/16
9/16
9
12
2
1/3
5
1/2
5/8
12
16
2
1/3
6
9/16
11/16
18
24
2
1/3
8
3/4
7/8
34
46
2
1/3
10
7/8
1
46
62
1-1/2
1/4
12
1-1/16
1-1/4
75
102
1
1/6
14
1-3/16
1-3/8
90
122
1
1/6
16
1-5/16
1-1/2
105
142
3/4
1/8
20
1-5/8
1-7/8
140
190
3/4
1/8
24
1-7/8
2-1/8
160
217
1/2
1/12
* The torque values shown are based on lubricated connections
as in re-assembly.
FLARE
FLARESEAT
BODY
NUT
A
B
C
LOCKNUT
WASHER
O-RING
GROOVE
FITTING
SEAT