B.  The shutoff valve is on the APU upper shroud. You must remove the
 shutoff valve through the opening in the horizontal web above the upper
 shroud.

 C.  You can get access to the shutoff valve through the access door forward
 of the APU compartment.

 TASK 49-51-21-004-001
 2.  Cooling Air Shutoff Valve Removal (Fig. 401)
_________________________________
 A.  Special Tools and Equipment
 (1)  F71336-501 - Horizontal Stabilizer Trim Lock
 B.  Access
 (1)  
Location Zones
 101 Control Cabin, LH
 205 Electronic Compartment
 701 Tail Compartment
 703 APU Compartment

 (2)  
Access Panels
 1201 Electronic Equipment Access Door
 3701 Stabilizer Compartment Access Door

 C.  Procedure
 S 864-002
 (1)  
Set the horizontal stabilizer trim in the full up position.

 S 864-003

 (2)  
Set the switch and the circuit breakers:

 (a)  
Set the APU master switch, on the P5 forward overhead panel, to the OFF position and attach a DO-NOT-OPERATE tag.

 (b)  
Open these circuit breakers on the P6 Circuit Breaker Panel and attach the DO-NOT-CLOSE tags: 1) STABILIZER TRIM ACTUATOR 2) STABILIZER TRIM CONT 3) AUTO FLT CONT SYS B MACH TRIM AC 4) AUTO FLT CONT SYS B MACH TRIM DC 5) AFDS MCP CRS-2 6) AUTO FLT CONT SYS B SNSR EXC AC 7) AUTO FLT CONT SYS B FCC DC 8) AUTO FLT CONT SYS B ENGAGE INTLK B 9) AUTO FLT CONT SYS B WARN LIGHT BAT

 (c)  
Open these circuit breakers on the P18 Circuit Breaker Panel and attach the DO-NOT-OPERATE tags: 1) AUTO FLT CONT SYS A MACH TRIM AC

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////////////////////////A / GTCP85-129 SERIES /737-300/400/500/ ENGINES /MAINTENANCE MANUAL ////////////////////////
SEE A
FLIGHT COMPARTMENT
YOKE
STABILIZER
TRIM WHEEL

TRIM WHEEL CONTROL STAND
HANDLE
STABILIZER TRIM LOCK
A
Cooling Air Shutoff Valve Installation
Figure 401 (Sheet 1)

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G99804
SEE B
STABILIZER
JACKSCREW

STABILIZER TRIM 
ELECTRICAL ACTUATOR  ELECTRICAL 
CONNECTOR 
ELECTRICAL 
CONNECTOR 

AUTOPILOT STABILIZER TRIM SERVO
MANUAL TRIM DRIVE CABLE DRUM
B
Cooling Air Shutoff Valve Installation Figure 401 (Sheet 2)
G99805
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////////////////////////A / GTCP85-129 SERIES /737-300/400/500/ ENGINES /MAINTENANCE MANUAL ////////////////////////
HORIZONTAL WEB 
LIGHTENING HOLES 
ACCESS DOOR 
INLET DUCT FOR THE COOLING AIR  SHUTOFF VALVE SEE A  PNEUMATIC ACTUATOR  UPPER SHROUD 

COOLING AIR FAN 
CROSSOVER DUCT FOR THE COOLING AIR  FWD 

PRESSURE LINE
NUTWASHER (2 LOCATIONS)
INLET DUCT FOR THE COOLING AIR
UPPER BOLTSHROUD FWD
A
Cooling Air Shutoff Valve Installation Figure 401 (Sheet 3)
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