(6)
Check engine oil pressure indicator, on center panel, for indication of oil pressure. Toward end of motoring run, LOW OIL PRESSURE warning light will go out as engine oil pressure reaches 35-38 psi.
(7)
Discontinue motoring by returning engine start switch to OFF.
NOTE: Clearing the engine of trapped fuel and vapors requires about 20 seconds of motoring.
6. New Engine Fuel Control Bleeding and Depreserving
A. General
(1)
Bleeding and depreservation of the engine fuel system is necessary prior to operation of a newly installed engine or fuel control to purge air and inhibiting oil from the fuel control.
(2)
It is not necessary to bleed and depreserve the engine fuel system after changing an engine fuel pump, fuel flowmeter, fuel heater, or after removal and subsequent installation of an engine fuel strainer. During the next engine run it will be necessary to purge air from the engine fuel system by exercising the throttle four or five times between idle and 90% N2 rpm, or until normal engine operation and throttle response is obtained.
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B. Equipment and Materials
(1)
PWA-12386 adapter or adapter plate fitted with a No. 16 Aeroquip fitting and length of hose for draining fluid from the fuel pressurizing and dump valve filter pad
(2)
Six gallon container (minimum)
C. Prepare Fuel Control for Bleeding and Depreserving
(1)
Remove engine left removable cowl panel (Ref 71-11-11).
(2)
Perform Engine Operation Preparations in par. 3.
D. Bleed and Depreserve Fuel Control
(1)
On the forward overhead panel, position aft fuel pump switch, for the tank numbered the same as the engine being bled, to ON and check that its low pressure light goes out.
(2)
Position forward fuel pump switch, for tank numbered the same as the engine being bled, to ON and check that its low pressure light goes out.
Note: If you must use the fuel boost pumps in the center tank, you must have a maintenance person or observer in the flight compartment to continuously monitor the LOW PRESSURE lights. Turn the applicable fuel boost pump to the OFF position if the LOW PRESSURE light for the center tank stays on.
(3)
Check the following items:
(a)
FUEL light on annunciator panel at pilot's glare shield is out.
(b)
FUEL VALVE CLOSED light on forward overhead panel is out if engine fuel shutoff valve is open.
NOTE: Engine fuel shutoff valve will be closed and FUEL VALVE CLOSED light will be dim whenever start lever is at CUTOFF. Valve will open and light will go out when start lever is advanced to IDLE.
(c)
Applicable engine bleed air valve switch is on (forward overhead panel).
(4)
To prevent an inadvertent start during fuel control depreservation, pull (open) Engine Start Ignition circuit breakers and Low Energy Ignition circuit breakers (if applicable), on P6 panel.
(5)
Check engine-driven fuel pump inlet pad for leaks.
(6)
Position a 6-gallon capacity container beneath the fuel pressurizing and dump valve.
(7)
Remove the fuel filter and cover from the square pad on the rear side of the fuel pressurizing and dump valve, (P & D valve).
CAUTION: USE CARE TO PREVENT FILTER DAMAGE DURING REMOVAL AND INSTALLATION.
(8)
Install PWA-12386 adapter, or equivalent, on P & D valve pad and connect a suitable length of hose to the adapter outlet fitting to drain fuel to the 6-gallon (minimum) container. (See figure 204.)
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G96461
504 Engine Fuel System Depreservation Connection
May 15/79 Figure 204 71-09-100
Page 213
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
(9) Move engine start switch to GRD position and motor engine to approximately 20-25 percent N2. Advance start lever to IDLE and pass at least 2 gallons of fuel overboard through P&D valve drain hose. Observe starter duty cycle for motoring engine.
CAUTION: IF THIS SWITCH IS RETURNED TO OFF PRIOR TO END OF MOTORING RUN, IT MUST NOT BE ENGAGED UNTIL 30 SECONDS AFTER ENGINE AND STARTER HAVE STOPPED ROTATING.
NOTE: Cycling the thrust lever between idle and maximum thrust position while motoring the engine will assist purging air from the fuel control.
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