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MAINTENANCE MANUAL
CAUTION:_______DO NOT USE FORCE TO INSTALL THE GUIDE TUBE. THE GUIDE TUBE MUST EASILY INSTALL IN THE PORT. DAMAGE TO THE GUIDE TUBE CAN OCCUR.
(d)
Install the PWC 41494 guide tube in the temperature sensor boss. 1) Attach the tube in its position.
CAUTION:_______BE VERY CAREFUL WITH THE BORESCOPE DEVICE. THIS DEVICE CAN BE EASILY DAMAGED. DO NOT TWIST OR HOLD THE DEVICE TIGHTLY. DO NOT LET THE BORESCOPE DEVICE FALL TO THE GROUND. DAMAGE TO THE BORESCOPE CAN OCCUR.
(e)
Connect the fiberscope cable to the light source.
1) If the light is not sufficiently bright, adjust the intensity knob to make the light brighter.
L.E.
ANY NICK OR DENT IN THIS AREA MORE THAN 0.250 INCH (6.350 mm) OF THE BLADE L.E. HEIGHT IS NOT PERMITTED.
Load Impeller Borescope Inspection
Figure 603 (Sheet 2)
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CAUTION: MAKE SURE THE ACTUATOR LEVER FOR THE DISTAL TIP IS IN THE
_______ NEUTRAL POSITION WHEN YOU INSTALL OR REMOVE THE BORESCOPE. THIS WILL PERMIT THE TIP TO MOVE FREELY IN THE GUIDE TUBE.
CAUTION: MAKE SURE YOU LET 40 MINUTES GO BY AFTER AN ENGINE
_______ SHUTDOWN BEFORE YOU DO THE INSPECTION. DAMAGE TO THE BORESCOPE CAN OCCUR IF THE APU IS TOO HOT.
(f)
Slowly install the borescope tip in the guide tube while you look through the eyepiece. 1) Stop the installation when you can see the load impeller.
(g)
If it is installed, remove the crank cover on the load gearbox (Fig. 601): 1) Remove the two bolts and the washers that attach the crank
cover to the load gearbox. 2) Remove the crank cover with the PWC 41350 puller. 3) Remove and discard the packing.
(h)
Attach a wrench to the square end socket of the gear shaft.
CAUTION: MAKE SURE THE BORESCOPE DISTAL TIP DOES NOT ENGAGE THE
_______ LOAD IMPELLER BLADES. DAMAGE TO THE BLADES AND THE BORESCOPE CAN OCCUR WHEN YOU TURN THE LOAD SECTION.
(i) Examine the load impeller while a different person turns the load section with the wrench: 1) Visually examine the load impeller to make sure it is in
the inspection limits (Ref Fig. 603).
a) Cracks in the impeller blades are not permitted.
b) Nicks and dents larger than 0.250 inch (6.35 mm) on the
blade leading edge are not permitted.
c) Nicks or dents less than 0.250 inch (6.35 mm) on the blade leading edge are permitted if you do a borescope inspection at 300 APU hours.
NOTE: Subsequent inspections are required at 3000 APU
____ hour intervals, if the damage does not change and no cracks have developed at this inspection.
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d) Unusual bends or damage to the leading edge of the impeller blades are not permitted.
(j)
When you complete the inspection, carefully remove the borescope and the guide tube from the load impeller housing.
(k)
Install the T12 temperature sensor: 1) Install a new copper gasket on the T12 temperature sensor. 2) Install the T12 temperature sensor in the load impeller
housing. 3) Tighten the sensor to 150-170 pound-inches (16.8-19.2 N.m).
(l)
Connect the P23 electrical connector to the T12 temperature sensor.
NOTE: The connector is fully tight when the indicator is
____
in the orange color band.
(m) If the power turbine inspection is not to be done at this time, install the crank cover: 1) Install a new packing, lubricated with engine oil, on the
crank cover. 2) Install the crank cover on the load gearbox with the two washers and the bolts. 3) Tighten the bolts to 36-40 pound-inches (4.0-4.5 N.m).
S 296-006
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