TM 1-1520-238-T-7
10–214
Change 3
10–76. PRESSURE REFUELING/DEFUELING – MAINTENANCE OPERATIONAL CHECK (cont)
10–76
Task
Result
m. Place suitable containers under forward and
aft fuel sump drains (fig. 10–83), and drain
remaining fuel from fuel sumps
(TM 1-1520-238-23).
n. Repeat steps e. and f.
o. Perform pressure refueling
(TM 1-1520-238-23).
p. Check forward vent tube for air flow.
If air does not flow through vent tube during pressure
refueling, stop refueling immediately, then check vent
tube for obstructions/physical damage.
q. During pressure refueling, on refueling panel
(fig. 10–79) check FUEL QTY indicator for
increase.
If FWD FUEL QTY indicator does not show increase,
replace forward fuel cell pilot valve
(TM 1-1520-238-23).
If AFT FUEL QTY indicator does not show increase,
replace aft fuel cell pilot valve (TM 1-1520-238-23).
r. During pressure refueling, check pressure
fuel manifold (fig. 10–83), and fuel cells for
leakage
If leakage occurs from fuel cells, go to
paragraph 10–12.
If pressure fuel manifold leaks during refueling,
replace pressure fuel manifold (TM 1-1520-238-23).
NOTE
When fuel cell is full LVL CONT VALVES CLOSED indicator does not light, but
fuel stops flowing into that fuel cell. If fuel starts flowing from either fuel cell vent
during pressure refueling, replace the fuel level control pilot valve and
fuel/defuel shutoff valve in that fuel cell (TM 1-1520-238-23).
s. When desired fuel has been loaded, set
appropriate LVL CONT VALVES switch to
CLOSE on refueling panel. The valve
CLOSED indicator is lighted, and the FUEL
QTY indicator for selected cell stops
increasing.
If AFT CLOSED indicator is not lighted with AFT TNK
switch set to CLOSE, replace lamp
(TM 1-1520-238-23). If lamp is still not lighted, go to
paragraph 10–89.
IF FWD CLOSED indicator is not lighted with FWD
TNK set to CLOSE, replace lamp
(TM 1-1520-238-23). If lamp is still not lighted, go to
paragraph 10–88.
If FWD FUEL QTY indication increases with FWD
TNK switch set to CLOSE, go to paragraph 10–95.
If AFT FUEL QTY indication increases with AFT TNK
switch set to CLOSE, go to paragraph 10–96.
