Technical data

13773-001
28-10
Page 10 30 Nov 2000
(a) A running leak will vary in size depending on location and intensity of the leak. Fuel usu-
ally will flow and immediately drip after being wiped dry.
F. Fuel Drain Valves (See Figure 28-103)
(1) Removal - Fuel Drain Valves
(a) Drain the corresponding fuel tank. (Refer to 12-10)
(b) Cut safety wire and remove drain valve (fuel tank drain valves only).
(2) Installation - Fuel Drain Valves
WARNING:
The collector tank drain valves are certified to tolerate swept stroke
lightning. To meet and maintain protection levels, the drain valves
must be installed onto a clean, bare metal surface. If the base of the
drain valve doesn’t make full contact with the access panel it may be
possible for lightning currents to arc to the base of the drain valve and
create potential ignition sources in the tank.
The collector tank access panels must never have paint or any other
type of exterior finish in between the drain valves and the access pan-
els.
(a) Inspect drain valve contact area for any paint or other contaminates. Remove contami-
nates as necessary to obtain a clean and bare metal contact area.
(b) Install and torque the drain valve with a new o-ring. Torque collector tank drain valves to
100-190 inch-pounds (11-20.9 Nm).
(c) Inspect the drain valve to ensure the entire base of the drain valve makes contact with the
access panel.
(d) Safety wire drain valve (fuel tank drain valves only). (Refer to 20-50)
(e) Fill fuel tank and inspect for leaks. If a fuel leak is observed, repair as required. (Refer to
51-10)
(f) Place the fuel sampler cup into the drain valve and inspect the drain valve for proper oper-
ation. Inspect the fuel for any contaminates.
(3) Inspection/Check - Fuel Drain Valves
(a) Visually inspect drain valves for leaks or seepage. If leaks or seepage is noted, replace
drain valve.