TM 5-3805-280-10
Maintenance
SERVICE RECOMMENDATIONS FOR
FLARED CONNECTIONS--STRAIGHT OR
TAPERED THREADS
1. Inspect flare and flare seat. They must be free of dirt
or obvious defects.
2. Defects in the tube flare cannot be repaired.
Overtightening a defective flared fitting will not stop
leaks.
3. Align the tube with the fitting before attempting to start
Straight Thread
the nut.
4. Lubricate the male threads with hydraulic fluid or
petroleum jelly.
5. Index angle fittings and tighten by hand.
6. Tighten fitting or nut to torque value shown on the
chart. Do not allow hoses to twist when tightening
fittings.
a
TORQUE CHART
b
Straight Thread
Tapered Thread
Tapered Thread
Thread
lb-ft
Size
Nm
lb-ft
Nm
1/8
15
11
1/4
20
15
45
33
3/8
29
21
69
51
1/2
49
36
93
69
3/4
69
51
176
130
1
157
116
343
253
1-1/2
196
145
539
398
2
255
188
588
434
Torque tolerance is 10%.
a
b
With seat face.
NOTE: If female thread is cast iron (control valves, brake
valves motors, etc.), torque must be reduced
approximately 10%.
04T,90,M171 1928JAN921/1
20-25