MacDon A40-D User Manual
Page 102

SECTION 7 MAINTENANCE AND SERVICING
169000 / 169040
100
Revision E
7.3.1.5
O-Ring Face Seal (ORFS) Hydraulic 
Fittings 
* Torque values and angles shown are based on lubricated
connection, as in re-assembly.
** Always default to the torque value for evaluation of adequate
torque.
*** O-ring face seal type end not defined for this tube size.
a. Check components to ensure that the sealing
surfaces and fitting threads are free of burrs, 
nicks, and scratches, or any foreign material. 
b. Apply lubricant (typically Petroleum Jelly) to
O-ring and threads. If O-ring is not already 
installed, install O-ring. Align the tube or hose 
assembly. 
c. Ensure that flat face of the mating flange comes
in full contact with O-ring.
d. Thread tube or hose nut until hand-tight. The
nut should turn freely until it is bottomed out. 
Torque fitting further to the specified number of 
F.F.F.T (“Flats From Finger Tight”), or to a given 
torque value in the table shown in the opposite 
column. 
NOTE
If available, always hold the hex on the 
fitting body to prevent unwanted rotation 
of fitting body and hose when tightening 
the fitting nut. 
e. When assembling unions or two hoses together,
three wrenches will be required.
SAE
NO.
THD
SIZE
(in.)
TUBE
O.D.
(in.)
TORQUE VALUE*
RECOMMENDED
TURNS TO
TIGHTEN
(AFTER FINGER
TIGHTENING)**
ft·lbf N·m
Tube
Nuts
Swivel
& Hose
3 *** 3/16 ---
---
---
---
4 9/16 1/4 11–12 14–16
1/4
–
1/2
1/2–3/4
5 *** 5/16 ---
---
---
---
6 11/16 3/8 18–20 24–27
1/4
–
1/2
1/2–3/4
8 13/16 1/2 32–35 43–47
10 1 5/8 45–51 60–68
12 1-3/16 3/4
67–71
90–95
1/3–1/2
14 1-3/16 7/8
67–71
90–95
16 1-7/16 1
93–100 125–135
20 1-11/16 1-1/4 126–141 170–190
24 2 1-1/2
148–167
200–225
32
2-1/2
2 --- --- --- ---
