6-4. Fuel System Tubes - Removal, Cleaning, and Installation - Continued
Fuel System Tubes
Fuel System Tubes and
Rigid steel tubing must align with its mating
fittings in the free state such that both
coupling nuts will engage two full threads of
their mating fittings with light finger
pressure. The tube must not be stretched
during final tightening of the coupling nuts.
Adjustments may be made by bending the
tube at the principal bend or bends. All
bending must be accomplished with the tube
removed from the engine. Flattening effect as
a result of reforming shall not exceed 15
percent of the tube OD.
Tighten No. 4 size
coupling nut 80 to 120 in.
lb (0.9-1.4 kg/m). Tighten
No. 5 size coupling nuts
150 to 200 in. lb (1.7-7.3
Align rigid steel tubing
with its mating fittings.