CESSNA®
MODEL 525 (SERIALS -0685 AND -0800 AND ON)
MAINTENANCE MANUAL
GARMIN RUDDER AUTOPILOT SERVO ASSEMBLY - REMOVAL/INSTALLATION
1.
General
A.
This section gives the removal and installation procedures for the Garmin Rudder Autopilot Servo
Assembly. The Garmin Rudder Autopilot Servo Assembly includes the Garmin GSA 80 Rudder
Autopilot Servo Actuator and the Garmin GSM 86 Rudder Autopilot Servo Gear Box. For a general
description of the rudder autopilot function, refer to Auto Flight - General. For more detailed
Garmin GSM 86 maintenance data refer to the GSM 86 Servo Gear Box Installation Manual P/N
190-00303-83 found in the Supplier publication List.
2.
Tools and Equipment
A.
Refer to Chapter 22, Auto Flight - General Tools and Equipment.
3.
Garmin GSA 80 Rudder Autopilot Servo Actuator (Motor) Removal/Installation
A.
Remove the Rudder Autopilot Servo Actuator (Motor) (Refer to Figure 401).
(1) Remove the electrical power from the airplane.
(2) Disengage the Automatic Flight Control System (AFCS) circuit breaker on the right circuit breaker
panel in the cockpit.
(3) Open the tailcone baggage compartment door. Refer to Chapter 6, Dimensions and Areas -
Description and Operation.
(4) Remove aft baggage compartment panel 321AL to get access to the rudder autopilot servo
actuator. Refer to Chapter 6, Access Plates and Panels Identiication - Description and
Operation.
(5) Disconnect the electrical connector (JT310) from the rudder autopilot servo actuator electrical
connector.
(6) Remove the bolts and the washers that attach the rudder autopilot servo actuator to the rudder
autopilot servo gear box.
(7) Remove the rudder autopilot servo actuator from the rudder autopilot servo gear box and the
airplane.
(8) If necessary, use a clean, lint-free cloth and remove unwanted grease buildup from the rudder
autopilot servo actuator output gear.
(9) If the rudder autopilot servo actuator is not going to be installed immediately, put covers over the
openings to keep the rudder autopilot servo gear box and rudder autopilot servo actuator clean.
B.
Install the Rudder Autopilot Servo Actuator (Motor) (Refer to Figure 401).
(1) Remove the protective covers from the rudder autopilot servo gear box and rudder autopilot
servo actuator openings.
(2) Apply a thin layer of Aeroshell 33MS grease or an equivalent to the rudder autopilot servo
actuator output gear. Refer to Chapter 22, Auto Flight - General.
(3) Put the rudder autopilot servo actuator in it's correct position on the rudder autopilot servo gear
box.
(4) Align the splines on the rudder autopilot servo actuator shaft with the splines in the rudder
autopilot servo gear box.
(5) Starting with two opposite corner bolts, tighten all bolts until 0.01 to 0.03 Inches (0.25 to 0.76
mm) from fully seated.
(6) Verify that the rudder autopilot servo actuator is still slightly loose relative to the rudder autopilot
servo gear box, ensuring there is still relative movement between the two units.
(7) Starting with two opposite corner bolts, torque all bolts from 25.00 to 40.00 inch-pounds (2.82
N-m to 4.51 N-m). Refer to Chapter 20, Torque Data - Maintenance Practices.
(8) Connect the electrical connector (JT310) to the rudder autopilot servo actuator electrical
connector.
(9) Engage the AFCS circuit breaker on the right circuit breaker panel in the cockpit.
22-10-25
Page 401
© TEXTRON AVIATION INC.
Nov 22/2017
ICA-525-27-00005
Form 2261 Rev 1
