Piper Navajo PA-31 Service Manual page 367

PIPER NAVAJO SERVICE MANUAL
6-139. CLEANING, INSPECTION AND REPAIR OF GEAR DOOR ACTUATING
CYLINDERS.
a.
Clean the cylinder parts with a suitable solvent and dry thoroughly.
b.
Inspect all threaded surfaces for cleanliness and for freedom from cracks and
excessive wear.
c. Inspect the plunger spring (21) of the plunger for evidence of breaks
and distortion. The free
length of the spring must be 1.055 inches and compressed to .875 inch under
a 35 ± 3.5 pound load.
d.
Inspect the gland end (5), spacer (6), piston (7), barrel (17), plunger (18)
and clevis end (22) for
cracks, chips, scratches, scoring, wear or surface irregularities which may
affect their function or the overall
function of the door actuator cylinder.
e. Repair of most parts of the landing gear door actuator assembly is impractical.
Replace defective
parts with serviceable parts. Minor scratches and scores may be removed
by polishing with fine abrasive
crocus cloth (Federal Specification P-C-458) providing their removal does not
affect the operation of the
unit. Install all new "O" rings and back up rings during reassembly of the actuator.
6-140. ASSEMBLY OF GEAR DOOR ACTUATING CYLINDER. (Refer to
Figure 6-31.)
a.
Install "O" ring (19) and back up ring (20) in the groove on the plunger
(18).
b.
Insert the spring (21) and plunger (18) into the clevis end (22). Install
the washer ( 11) and race
(10) over the end of the plunger (18).
c. With knurled nuts (13) on the barrel (17), install ""
rings (14) and back up rings (15) in grooves
on barrel.
d. Install "O" ring (9) and back up rings (8) in groove on piston (7) and install
balls (12) in holes of
piston.
e. Insert piston into barrel. Be sure that all six balls (12) are in place in the
piston as the piston is
inserted in the barrel.
f. Screw the barrel (17) into the clevis end (22). Tighten the barrel down snugly
against race, then
tighten knurled nut (13).
g.
Insert spacer (6) in barrel (17). Spacer (6) is used only in main landing gear
wheel door actuator.
h. Install "O" ring (4) and back up ring (3) in bore groove of gland end (5), lubricate
piston rod and
slide gland end over rod. Tighten the gland end on the barrel, aligning the hydraulic port fittings
of the
gland end with the port fitting in the clevis end.
i.
Tighten knurled nuts (13) to a torque value of 130 + 10 pounds. Install
lock wire on both
knurled nuts.
j.
Install locknut (2) and rod end (1).
6-141. INSTALLATION OF GEAR DOOR ACTUATING CYLINDER.
a. Position the cylinder on its mounting bracket and secure with attachment bolt.
b.
Extend the cylinder control rod enough to attach the rod end to the door
and secure with
attachment bolt.
c. Connect the hydraulic line to the cylinder.
d.
To bring the gear door back to the closed position, turn the master switch
ON, place the gear
selector switch in the down position and actuate the hand pump until the door
closes.
6-142. GEAR DOOR ACTUATING CYLINDERS (WIEBEL TOOL).
6-143. REMOVAL OF GEAR DOOR ACTUATING CYLINDERS. (Same as
Paragraph 6-137.)
Reissued: 10/12/79
HYRAULIC SYSTEM
2D13