MAINTENANCE/SERVICE
Form 169017
109
Issue – June 2008
7.4.2 Hydraulic
Fittings
7.4.2.1 O-ring
Type
Refer to illustration and proceed as follows:
a. Inspect O-ring and seat for dirt or obvious
defects.
b. On angle fittings, back off the lock nut until
washer bottoms out at top of groove.
c. Hand tighten fitting until back up washer or
washer face (if straight fitting) bottoms on face
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.
THD
SIZE
(in.)
NUT SIZE
ACROSS
FLATS
(in.)
TORQUE
VALUE*
RECOMMENDED
TURNS TO
TIGHTEN (AFTER
FINGER
TIGHTENING)
lbf-ft N·m Flats Turns
3/8 1/2 6 8 2 1/3
7/16 9/16 9 12 2 1/3
1/2 5/8 12
16 2 1/3
9/16 11/16 18 24 2
1/3
3/4 7/8 34
46 2 1/3
7/8 1 46
62
1-1/2
1/4
1-1/16 1-1/4 75 102 1
1/6
1-3/16 1-3/8 90 122 1
1/6
1-5/16 1-1/2 105 142 3/4
1/8
1-5/8 1-7/8 140 190 3/4 1/8
1-7/8 2-1/8 160 217 1/2 1/12
* The torque values shown are based on lubricated
connections as in reassembly.
7.4.2.2 Flare
Type
Refer to illustration and proceed as follows:
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.
e.
TUBE
SIZE
O.D.
(in.)
NUT
SIZE
ACROSS
FLATS
(in.)
TORQUE
VALUE*
RECOMMENDED
TURNS TO
TIGHTEN
(AFTER FINGER
TIGHTENING)
lbf-ft N·m Flats Turns
3/16 7/16 6 8 1 1/6
1/4 9/16 9 12 1 1/6
5/16 5/8 12 16 1 1/6
3/8 11/16 18 24 1 1/6
1/2 7/8 34 46 1 1/6
5/8 1 46 62 1 1/6
3/4 1-1/4 75 102 3/4 1/8
7/8 1-3/8 90 122 3/4 1/8
* The torque values shown are based on
lubricated connections as in reassembly.
LOCKNUT
WASHER
GROOVE
FITTING
O-RING
SEAT
FLARE
FLARESEAT
BODY
NUT