John Deere stx38 - Manual (Page 19)

3/20/97
2 - 11
SPECIFICATIONS AND INFORMATION O-RING SEAL SERVICE RECOMMENDATIONS
O-RING FACE SEAL FITTINGS
1. Inspect the fitting sealing surfaces. They must be
free of dirt or defects.
2. Inspect the O-ring. It must be free of damage or
defects.
3. Lubricate O-rings and install into groove using
petroleum jelly to hold in place.
4. Push O-ring into the groove with plenty of
petroleum jelly so O-ring is not displaced during
assembly.
5. Index angle fittings and tighten by hand pressing
joint together to insure O-ring remains in place.
6. Tighten fitting or nut to torque value shown on the
chart per dash size stamped on the fitting. Do not
allow hoses to twist when tightening fittings.
O-RING BOSS FITTINGS
1. Inspect boss O-ring boss seat. It must be free of dirt
and defects. If repeated leaks occur, inspect for
defects with a magnifying glass. Some raised
defects can be removed with a slip stone.
2. Put hydraulic oil or petroleum jelly on the O-ring.
Place electrical tape over the threads to protect O-
ring from nicks. Slide O-ring over the tape and into
the groove of fitting. Remove tape.
.
3. For angle fittings, loosen special nut and push
special washer against threads so O-ring can be
installed into the groove of fitting.
4. Turn fitting into the boss by hand until special
washer or washer face (straight fitting) contacts
boss face and O-ring is squeezed into its seat.
5. To position angle fittings, turn the fitting counter-
clockwise a maximum of one turn.
6. Tighten straight fittings to torque value shown on
chart. For angle fittings, tighten the special nut to
value shown in the chart while holding body of
fitting with a wrench.
a. Torque tolerance is ± 10 percent.
b. To be used if a torque wrench cannot be used.
After tightening fitting by hand, put a mark on nut or
boss; then tighten special nut or straight fitting the
number of flats shown.
Sealing Surface
O-ring
Sealing Surface
Groove
O-ring
STRAIGHT FITTING OR SPECIAL NUT TORQUE
Thread
Size
Torque
a
Number
of Flats
b
N•m lb-ft
3/8-24 UNF 8 (6) 2
7/16-20 UNF 12 (9) 2
1/2-20 UNF 16 (12) 2
9/16-18 UNF 24 (18) 2
3/4-16 UNF 46 (34) 2
7/8-14 UNF 62 (46) 1-1/2
1-1/16-12 UN 102 (75) 1
1-3/16-12 UN 122 (90) 1
1-5/16-12 UN 142 (105) 3/4
1-5/8-12 UN 190 (140) 3/4
1-7/8-12 UN 217 (160) 1/2
Special Nut
Special Washer Angle Fitting