Piper Aircraft Corporation Malibu Mirage PA-46-350P, Airplane Maintenance Manual

Page: 198 / 1956

PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
PAGE 4
Feb 28/07
1I20
12-10-00
4. Landing Gear Oleo Struts
WARNING: DO NOT RELEASE AIR BY REMOVING THE STRUT VALVE CORE OR FILLER PLUG.
DEPRESS THE VALVE CORE PIN UNTIL STRUT CHAMBER PRESSURE HAS
DIMINISHED.
CAUTION: DIRT AND FOREIGN PARTICLES FORM AROUND THE FILLER PLUGS OF THE
LANDING GEAR STRUTS, THEREFORE, BEFORE ATTEMPTING TO REMOVE THESE
PLUGS, THE TOPS OF THE STRUTS SHOULD BE CLEANED WITH COMPRESSED AIR
AND/OR WITH A QUICK DRYING SOLVENT.
Air-oil type oleo struts should be maintained at proper strut tube exposure for best oleo action. Nose
gear strut piston tube exposure is 1.7 ± .25 inches. Main gear strut piston tube exposure is 3.5 ± .25
inches -
except in S/N’s 4636196 and up where 3.4 ± .25 inches is required. Measure with the airplane
sitting on a level surface under normal static load. (Empty weight of airplane plus full fuel and oil). If the
strut has less tube exposure than prescribed, determine whether it needs air or oil by rocking the
airplane. If the oleo strut oscillates with short strokes (approximately one inch) and the airplane settles to
its normal position within one or two cycles after the rocking force is removed, the oleo strut requires
inflating. Check the valve core and filler plug for air leaks, correct if required, and add air or nitrogen as
described in Inflating Oleo Struts. If the oleo strut oscillates with long strokes (approximately three
inches) and the airplane continues to oscillate after the rocking force is removed, the oleo struts require
fluid. Check the oleo for indications of oil leaks, correct if required and add fluid as described in Filling
Oleo Struts. For landing gear and/or oleo strut repair procedures, refer to 32-10-00 and 32-20-00.
A. Filling Oleo Struts
To fill the nose or main gear oleo strut with fluid (MIL-H-5606), whether it be the addition of a small
or large amount, proceed as follows:
(1) Raise the airplane on jacks.
(2) Place a pan under the gear to catch spillage.
(3) At the filler plug, relieve air pressure from the strut housing chamber by removing the cap from
the air valve and depressing the valve core.
(4) There are two methods by which the strut chamber may be filled. They are as follows:
(a) METHOD I.
1 Remove the valve core from the filler plug at the top (or side) of the gear strut
housing. Allow the filter plug to remain installed.
2 Attach one end of a clean plastic hose to the valve stem of the filler plug and
submerge the other end in a container of hydraulic fluid.
NOTE: An air-tight connection is necessary between the plastic tube and the valve
stem. Without such a connection, a small amount of air will be sucked into
the oleo strut during each sequence, resulting in an inordinate amount of air
bubbles and a prolonged filling operation.
3 Fully compress and extend the strut thus drawing fluid from the fluid container and
expelling air from the strut chamber. By watching the fluid pass through the plastic
hose, it can be determined when the strut is full and no air is present in the chamber.
4 When air bubbles cease to flow through the hose, compress the strut fully and
remove the hose from the valve stem.
5 With the strut compressed, remove the filler plug to determine that the fluid level is
visible up to the bottom of the filler plug hole.
6 Reinstall the core in the filler plug and apply thread lubricant (Parker No. 6PB) to the
threads of the filler plug and install the plug in the top of the strut housing. Torque the
plug from 350 to 400 inch pounds.