Piper Arrow IV, Maintenance Manual

Page: 346 / 752

CHECK AND ADJUSTMENT OF GEAR BACK-UP EXTENDER ACTUATOR. (Refer to Figure 29-8.)
1. If diaphragm failure is suspected, note the following:
A. If the landing gear retracts or extends at too high an airspeed or will not retract at all unless the
back-up extender is placed in the override position, then the diaphragm is possibly defective.
B. If it is determined that the diaphragm is defective, then remove the back-up extender per
instructions given in Removal of Gear Back-Up Extender Actuator Assembly and install Piper Kit
No. 761 138V, Back-Up Gear Extender Diaphragm Replacement. Instructions for installing the
diaphragm are included in the kit.
C. Following completion of Replacement Kit, reinstall the extender unit in the aircraft and
functionally test and adjust as outlined below and in Operation Check of Retractable Landing Gear
System.
2. Adjustment of the gear back-up extender actuator is preset to allow the hydraulic valve of the actuator
to open when the airspeed is reduced below 103 KIAS for PA-28RT-201T or 95 KIAS for PA-28RT-201 with
the engine power OFF. This adjustment is accomplished by setting the tension of spring on the actuator with
adjustment screw as follows:
—NOTE—
The airspeed at which the hydraulic valve of the actuator opens
was preset at the factory under ideal conditions. There could be
some variations at different altitudes and atmosphere conditions.
—CAUTION—
The micro switch and eccentric bolt must not be adjusted. These
components are set at the factory under specific conditions, with
the use of special set-up equipment.
—NOTE—
This adjustment will require two persons, a qualified pilot and a
mechanic to set the actuator adjustment screw.
A. Remove the bottom of the rear seat.
B. The pivot screw should be torqued 8 to 10 inch-pounds.
C. Loosen the jam nut of the adjustment screw.
D. Ascertain that the electrical switch will actuate with the use of the emergency gear extension lever.
E. Fly the airplane (refer to Owner’s Handbook). Should the spring tension be out of adjustment very
much, it may be necessary to assist gear retraction with the use of the emergency gear extension
lever moved to the up override position.
F. Loosen the adjustment screw by turning counterclockwise until spring tension is free.
—WARNING—
While making adjustments, do not lay tools in area exposed by
the removal of floorboard. This may interfere with airplane
controls.
29-10-11
Page 29-25
Revised: November 6, 1979
2C19
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL