Inflating Oleo Struts; Servicing Tires; Tire Balancing - Piper Navajo Chieftain PA-31-350 Service Manual

NAVAO CHIEFTAIN SERVICE MANUAL
NOTE
An air-tight connection is necessary between the plastic tube and
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.
e. Extend the oleo strut by pulling down on the wheel. Fluid will be sucked into the oleo strut.
Compress and extend the oleo strut until it is full of fluid, and air bubbles cease to appear in the plastic
tube.
f. Compress the oleo strut to within 1/4 inch of full compression, allowing the excess fluid to
overflow.
g. With the oleo strut in the near compressed position, reinstall the valve core.
h.
Remove the airplane from the jacks.
i.
Inflate the oleo struts per instructions given in paragraph 2-34.
2-34. INFLATINGOLEOSTRUTS. Aftermakingcertainthatanoleostruthassufficientfluid.asdescribed
in paragraph 2-32. attach a strut pump to the air valve and pump up the oleo strut. The oleo struts should be
inflated until 3.25 inches of piston is exposed with normal static weight (Normal static weight is the empty
weight of the airplane plus full fuel and oil) on the gears. Before capping the valve, check for valve core leakage.
2-35. TIRES.
2-36. SERVICING TIRES. The tires should be maintained at the pressure specified in Table II-I. When
checking tire pressure, examine the tires for wear, cuts, bruises and slippage.
2-37. TIRE BALANCING.
Proper balancing is critical for the life of the aircraft tires. If a new tire is balanced upon installation it will
usually remain balanced for the life of the tire without having any shimmy or flat spots, and an inexpensive
balancer can be made that will balance almost any tire for light aircraft. (Refer to Paragraph 2-38 for
fabrication instructions.) Balance the tire as follows:
a. Mount the tire and tube (if one is used) on the wheel, but do not install the securing bolts. Install
the wheel bearings in the wheel; then, using the -7 bushings, -6 spacers, and -5 nuts, install the wheel-tire
assembly on the -8 pipe. Secure the -5 nuts finger-tight so that the wheel halves touch each other. Be sure
the bolt holes are aligned! Insert the -4 axle through the -8 pipe and place the wheel in the center of the
balancer. Make sure the axle is only on the chamfered edges of the balancer and that it is at 90
°
to the
sides of the balancer.
b. Release the tire. If it is out of balance it will rotate, coming to rest with the heaviest point on the
bottom. Tape a 1/2 ounce patch across top center of the tire. Rotate the tire 450 and release it again. If
the tire returns to the same position, add a I ounce patch and again rotate the tire and release it. Continue
this procedure until the tire is balanced.
c. When balance is attained, put a chalk mark on the sidewall directly below the patch. Use one
mark for each half ounce of weight needed. Mark the valve stem location on the tire and the opposite wheel
half to assure reassembly in the same position. Remove the wheel from the balance stand, break it down. and
clean the tire with toluol. Apply a coat of patch cement to both the patch and the inside center of the tire in
line with the chalk marks. When the cement has dried. install the patches making certain they are on the center
line of the tire and aligned with the chalk marks on the sidewall. Burnish the patches to remove trapped air. etc.
Reissued: 9/23/80
HANDLING AND SERVICING
1B22