NOTE: Step (4) is not necessary if the high pressure fuel line has been disconnected from the fuel atomizer for fuel supply line purging or APU depreserving.
(5)
Position BATTERY SWITCH to ON and remove placard.
NOTE: Do not position BATTERY SWITCH to ON at this time if unit is being preserved.
D. Motor Engine
(1)
Provide airplane with external power.
NOTE: No. 1 tank boost pump requires ac power.
(2)
Position No. 1 tank forward boost pump to ON.
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)
Position APU master switch to START and release.
NOTE: APU master switch will return to ON and engine motoring wil1 begin after APU fuel valve and air inlet door have opened. After approximately 60 seconds of motoring, motoring is terminated by a time limiting device in APU control unit.
(4)
Position APU master switch to OFF.
(5)
Verify proper operation of APU fuel shutoff valve (located on LH rear wing spar in LH wheel well).
(a) Observe that fuel valve position indicator has returned to closed position.
(6)
Repeat steps (3) and (4) as required.
CAUTION: TO AVOID DAMAGING APU, OBSERVE OPERATING LIMITS (FIG. 201).
E. Restore Airplane to Normal Configuration
(1)
Position No. 1 tank forward boost pump switch and BATTERY SWITCH to OFF and placard.
(2)
If motoring run was performed for maintenance other than fuel system purging or depreservation of engine, connect electrical plug to sequencing oil pressure switch.
(3)
If fuel system purging or engine depreservation was performed, disconnect fuel hose from high-pressure fuel line and connect fuel line to fuel atomizer.
(4)
Connect ignition unit power supply electrical plug to ignition unit.
(5)
Position lower shroud against upper shroud and close shroud latches.
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49-11-0 Page 206 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Sep 01/02
CAUTION: MAINTAIN A MINIMUM CLEARANCE OF 0.18 INCH BETWEEN ENGINE PLUMBING, FIRE DETECTOR, CLAMPS AND INSIDE SURFACE OF LOWER SHROUD.
EXERCISE EXTREME CARE NOT TO DAMAGE SHROUD DRAIN LINES WHEN HANDLING SHROUD.
(6)
Disengage APU compartment access door support rods and stow rods. Close and latch access door.
(7)
Remove placard.
4. Depreserve APU
A. General
(1) Depreservation of an engine consists of filling engine oil tank with lubricating oil, purging fuel control unit of preservative oil, operating engine for a short period, then replacing high and low pressure fuel filter elements and replacing oil filter element. Purging air from APU fuel system is required when fuel control unit or any other fuel system component is replaced on an existing engine or when low-pressure fuel filter is checked.
B. Equipment and Materials
WARNING: PROLONGED CONTACT OF LUBRICATING OIL WITH SKIN CAN CAUSE DERMATITIS, STAIN CLOTHING AND SOFTEN PAINT. REMOVE SATURATED CLOTHING IMMEDIATELY AND THOROUGHLY WASH SKIN AFTER CONTACT. PAINTED SURFACES SHOULD BE CLEANED IMMEDIATELY AFTER CONTACT WITH OIL.
(1)
Synthetic Gas Turbine Oil - MIL-L-7808, MIL-L-23699, or their commercial equivalents (Ref AiResearch Report GT-7800-R)
(2)
Cleaning Solvent - Federal Specification P-D-680, or equivalent
C. Depreserve Engine
(1)
Prepare for engine depreservation per par. 3.C.
(2)
Remove filler cap from APU oil tank.
(3)
Add oil until oil level is at FULL mark on dipstick.
(4)
Install filler cap on APU oil tank.
(5)
Manually open APU fuel shutoff valve at left rear wing spar, accessible at left main wheel well area.
(6)
Perform the following if unit has been preserved.
(a)
Reconnect fuel supply line to shroud fuel inlet port.
(b)
Install oil filter element in oil pump assembly.
(c)
Install fuel control unit high-pressure fuel filter element.
(d)
Remove protective covering and masking tape from air inlet; exhaust outlet, and cooling air outlet in access door.
(7)
Position BATTERY SWITCH to ON and remove placard.
(8)
Position No. 1 tank forward boost pump to ON.
CAUTION: SOME OILS ARE NOT COMPATIBLE WHEN MIXED. UNLESS COMPATIBILITY IS ASSURED, DO NOT MIX BRAND NAME OILS.
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