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

Page: 199 / 1956

PAGE 5
Feb 28/07
1I21
12-10-00
PIPER AIRCRAFT, INC.
PA-46-350P, MALIBU MIRAGE
MAINTENANCE MANUAL
(b) METHOD II.
1 Remove the filler plug from the top (or side) of the gear strut housing.
2 Raise the strut piston tube until it is fully compressed.
3 Pour fluid from a clean container through the filler opening until it reaches the bottom
of the filler plug hole. (Air pressure type oil container may be helpful.)
4 Install the filler plug finger tight and extend and compress the strut two or three times
to remove air from the housing.
5 Remove the filler plug, raise the strut to full compression and fill with fluid if needed.
6 Apply thread lubricant (Parker No. 6PB) to the threads of the filler plug. Reinstall the
filler plug and torque from 350 to 400 inch pounds.
7 With the airplane raised, compress and extend the gear strut several times to
ascertain that the strut actuates freely. The weight of the gear fork and wheel should
extend the strut.
8 Clean off overflow of fluid and inflate the strut as described in Inflating Oleo Struts.
9 Check that fluid is not leaking around the strut piston at the bottom of the housing.
B. Inflating Oleo Struts
After making certain that an oleo strut has sufficient fluid, attach a strut pump to the air valve and
inflate the oleo strut. The strut should be inflated until the correct inches of piston is exposed with
normal static load (empty weight of the airplane plus full fuel and oil) on the gears. Rock the
airplane several times to ascertain that the gear settles back to the correct strut position. If a strut
pump is not available, the airplane may be raised and line pressure from a high pressure air system
used.
NOTE: Moisture free compressed air may be used in lieu of nitrogen gas on a temporary basis;
however, the strut should be deflated and serviced with nitrogen as soon as possible.
Lower the airplane and, while rocking it, let air from the valve to bring the strut down to the proper
extension. (Before capping the valve, check for valve core leakage.)
If the airplane is on jacks, ensure that the struts are fully extended. Inflate the nose gear strut to
110 ± 11 psi and the main gear struts to 250 ± 25 psi. This is the preferred method.
5. Tires
Tubeless tires are designed to permit any air or nitrogen that is trapped in the cords or that diffuses
through the liner to escape through special sidewall vents. This venting prevents pressure build-up within
the cord body which might cause tread, sidewall or ply separation. Discounting tire growth after initial
inflation, once the tire has been inflated, the maximum permissible pressure drop due to diffusion is 5%
in any 24 hour period.
Vent holes penetrate the sidewall rubber to, or into, the cord body and may vary in size, depth and angle.
Therefore, the amount of diffusion through these holes will vary.
When water or a soap solution is brushed over the outside of an inflated tubeless tire, bubbles form.
Some vents may emit a continuous stream of bubbles. Others may produce intermittent bubbles. And
some may not bubble at all. This variety is normal and does not mean that there is anything wrong with
the tire. In fact, as long as a tubeless tire is inflated, there will be some diffusion from the vents. When
the loss rate exceeds 5% in 24 hours, recheck for possible injuries. Vents should remain open, so check
periodically to make sure they have not been covered over or closed by tire paint or spilled solvent. And
since vents may be covered during retreading, check for evidence that your retreads have been
revented.