27-21-12
 ALL  ú ú 02.1 Page 225 ú Sep 28/02
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A

757 MAINTENANCE MANUAL
 RUDDER RATIO CHANGER ACTUATOR (RRCA) - MAINTENANCE PRACTICES
____________________________________________________________
 TASK 27-21-13-002-001
 1.  Remove the Rudder Ratio Changer Actuator (RRCA) or its Parts____________________________________________________________
 A. General
 (1)  This task contains these procedures:
 -Rudder Ratio Changer Actuator (RRCA) - Removal
 -
RRCA Filter - Removal

 -
RRCA Screen - Removal

 -
RRCA Solienoid Valve - Removal

 -
RRCA Electro-Hydraulic Servo Valve (EHSV) - Removal.

 Because this task contains more than one procedure, do only the applicable group of steps.
 (2)  
To start one of these procedures, do the "Prepare for Removal" group of steps. Then, do the group of steps that is necessary to remove the component.

 B.
Equipment

 (1)  
Nose Gear Towing Lever Lockpin - A09003-1

 C.
References

 (1)  
06-42-00/201, Empennage Access Doors and Panels

 (2)  
20-10-24/201, Rigging Pins

 (3)  
24-22-00/201, Electrical Power - Control

 (4)  
27-21-00/501, Rudder and Rudder Trim Control System

 (5)  
27-21-12/201, Rudder Ratio Changer Mechanism

 (6)  
29-11-00/201, Main (Left, Right, and Center) Hydraulic Systems

 D.
Access

 (1)  
Location Zones 211/212 Control Cabin 324 Vertical Stabilizer - Rear Spar to Trailing Edge

 (2)  
Access Panels
 324AL Body to Fin Seal
 324BL Aft Side of Rear Spar and Rudder Hinge

 E.
Prepare for the Removal (Fig. 201)

 (1)  
Supply electrical power (Ref 24-22-00).

 (2)  
Open access panels 324AL and 324BL (Ref 06-42-00).

 S 862-002
 S 012-003
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú

 27-21-13
 ALL  ú ú 01 Page 201 ú Jun 20/90
BOEING PROPRIETARY - Copyright (C) - Unpublished Work - See title page for details.
A

757
MAINTENANCE MANUAL

 S 492-004
 CAUTION:_______MAKE SURE TO PUT A COVER ON THE APU INLET. IF HYDRAULIC FLUID GOES INTO THE INLET, IT CAN CAUSE SMOKE AND CONTAMINATION OF THE CABIN AIR SUPPLY.
 (3)  
Install a cover to keep the hydraulic fluid out of the APU inlet and away from the inlet area.

 S 862-005

 (4)  
Remove the pressure from the left, right, and center hydraulic systems and reservoirs (Ref 29-11-00).

 S 862-006

 (5)  
Move the FLT CONTROL SHUTOFF L, C, and R switches on the right side panel, P61, to OFF. Attach DO-NOT-OPERATE tags and make sure the switch position lights are ON.

 S 862-007

 (6)  
Open these circuit breakers on the overhead panel, P11, and attach DO-NOT-CLOSE tags:

 (a)  
11D18 or 11G10, RUD RATIO

 (b)  
11H17, FLT CONT SHUTOFF TAIL LEFT

 (c)  
11H18, FLT CONT SHUTOFF TAIL CTR

 (d)  
11H28, FLT CONT SHUTOFF TAIL RIGHT

 S 042-008
 (7)  
Move the towing lever on the metering valve module to the tow position and install the towing lever lockpin in the nose gear (Fig. 202).

 S 042-010

 (8)
Install rig pin R3 (for the feel, centering, and trim mechanism).

 F.
Rudder Ratio Changer Actuator (RRCA) - Removal (Fig. 201)

 S 032-011
 (1)  
Disconnect the hydraulic hoses (15, 18, 19) from the RRCA (37) and tag them for identification.

 (2)  
Put caps on the hydraulic hoses and in the ports of the RRCA.

 S 032-013

 (3)  
Disconnect these components:

 (a)  
the electrical connectors (26, 33) from the RRCA and tag them for identification

 (b)  
the RRCA (37) from the left ratio changer crank (9)

 S 032-012
 EFFECTIVITYùùùùùùùùùùùùùùùùùùùùùùùùùùùùùù. ú
　
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