H.
Return flaps to full up position.
I.
Reduce airspeed to zero; remove pitot-static test unit.
J.
Close GRD HYDRAULIC INTERconnect switch and turn off B-hydraulic pressure.
K.
Remove angle of airflow calibrator.
L.
Remove electrical power if no longer required.
512
22-11-381 Page 502 BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details. Feb 20/85
HYDRAULIC PRESSURE SWITCH - REMOVAL/INSTALLATION
EFFECTIVITY
WA N235WA thru N259WA SA ZS-SIA and on GJ B-2509 and B-2510
1. General (Fig. 401)
A. Hydraulic pressure switch is installed on the autopilot actuators for aileron and elevator controls on both the A and B systems.
B. Take precaution to prevent hydraulic fluid from spilling on airplane. Should any fluid spill on airplane, decontaminate (Ref 12-40-0).
2. Equipment and Materials
A. Hydraulic Fluid - BMS 3-11 or Skydrol Assembly Lube - MCS 352 (Ref 20-30-21).
B. Suitable container to catch hydraulic fluid.
3. Remove Hydraulic Pressure Switch
A. Depressurize applicable hydraulic system (Ref 29-11-0 MP and 29-12-0 MP).
WARNING: PRESSURIZING HYDRAULIC SYSTEMS WILL SUPPLY POWER TO RUDDER, AILERON, ELEVATOR, SPOILER AND SPEED BRAKE SYSTEMS. CARE SHOULD BE TAKEN TO ISOLATE OR TAG SYSTEMS NOT BEING TESTED TO PREVENT INJURY TO PERSONNEL OR DAMAGE TO AIRPLANE AND EQUIPMENT.
B. Open all autopilot circuit breakers on P6 and P18 load control center.
C. Disconnect electrical connector from hydraulic pressure switch.
D. Remove hydraulic pressure switch from autopilot actuator assembly; discard O-ring.
NOTE: Plug open hydraulic line to prevent contamination and leakage.
4. Install Hydraulic Pressure Switch
A. Lubricate new O-ring and threads of hydraulic pressure switch with assembly lube or hydraulic fluid.
B. Install O-ring on hydraulic pressure switch and install switch in autopilot actuator assembly.
C. Torque hydraulic pressure switch 70 to 120 pound inches and install lockwire.
D. Connect electrical connector to hydraulic pressure switch.
E. Close circuit breakers opened in step 3.B.
F. Test hydraulic pressure switch (Ref 22-11-391 A/T).
Feb 20/87 22-11-391 Page 401
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
Hydraulic Pressure Switch Installation 5C9
22-11-391 Figure 401 Oct 20/88
Page 402
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
HYDRAULIC PRESSURE SWITCH - ADJUSTMENT/TEST
EFFECTIVITY
WA N235WA thru N259WA SA ZS-SIA and on GJ B-2509 and B-2510
1. General
A. The hydraulic pressure switch must be tested whenever it is replaced.
B. The hydraulic pressure switches are installed on the autopilot actuator for aileron and elevator controls.
C. AP/FD BITE is used to test the hydraulic pressure switch after installation.
D. Prepare AFCS for BITE by providing electrical power to autopilot, PDC, attitude reference, compass, VHF NAV, LRRA, air data, autothrottle, and flight instruments.
2. Perform Hydraulic Pressure Switch Test
A. Select PDC CDU to autopilot BITE by selecting STBY on PDC CDU, pressing RCL, (-), then selecting page 5 (autopilot BITE).
B. Select YES (ENG) to SYMPTOM/PIREP; YES to autopilot; YES to ENG INTLKS. This selects ENGAGE INTERLOCKS test (No. 8 or 58). Select desired channel to be tested.
C. Perform BITE INITIALIZE steps and required actions as requested on CDU and perform BITE.
D. Follow instructions to provide system diagnostic routine if a BITE fails. Replace indicated component and recycle system through BITE until system passes.
E. Remove electrical and hydraulic power if no longer required.
Feb 20/87 22-11-391 Page 501
BOEING PROPRIETARY - Copyright . - Unpublished Work - See title page for details.
AUTOPILOT DISENGAGE SWITCH - REMOVAL/INSTALLATION
1. General (Fig. 401)
A. Two autopilot disengage switches, one on each outboard horn, are located on the pilots' control wheels. Each switch is a single-action, multipole, pushbutton type switch which is held in place with a switch plate by a single screw.
2. Remove Switch
A. Open all autopilot circuit breakers on P6 and P18 panel.
B. Remove screw and switch plate from switch and carefully pull switch assembly from control wheel.
C. Note and mark arrangement of color coded wires and disconnect wires from terminals of switch. See Fig. 402 for wiring configuration.
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