3.
After the filter has been replaced, tighten the attaching bolt within 15 to 18 foot-pounds of torque. Lockwire the bolt through the loops on the side of the housing to the drilled head of the thermostatic valve. Be sure the lockwire is replaced at both the attaching bolt head and the thermostatic oil cooler bypass valve.
12-10-00 Page 12-12 Revised: February 28, 2002
1F12
SCHEDULED SERVICING.
LANDING GEAR.
SERVICING OLEO STRUTS.
— CAUTION —
DO NOT EXCEED THESE TUBE EXPOSURES.
The air-oil type oleo strut should be maintained at proper strut piston tube exposures for best oleo action. The nose gear strut must have approximately 2.70 ± 0.25 inches of piston tube exposed, while the main gear strut requires approximately 2.60 ± 0.25 inches of tube exposure. These measurements are taken with the airplane sitting on a level surface under normal static load.
— Note —
Normal Static load is the empty weight of the airplane plus full fuel and oil.
— WARNING —
DO NOT RELEASE AIR BY REMOVING THE STRUT VALVE CORE OR FILLER PLUG. DEPRESS THE VALVE CORE PIN UNTIL THE STRUT CHAMBER PRESSURE HAS DIMINISHED.
— CAUTION —
CLEAN ALL DIRT AND FOREIGN PARTICLES FROM AROUND THE FILLER PLUGS WITH COMPRESSED AIR AND/OR WITH A QUICK DRYING SOLVENT.
If the strut has less tube exposure than prescribed, determine whether it needs air or oil by rocking the airplane. If the oleo strut oscillated 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. 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. For repair procedures of the landing gear and/ or oleo struts, refer to Chapter 32 of this manual.
FILLING NOSE GEAR OLEO STRUT.
The nose gear should be serviced with MIL-H-5606 hydraulic fluid only. The nose gear is filled as follows:
1.
Raise the airplane on jacks as explained in Chapter 7, and place a pan under the gear to catch spillage.
2.
Remove the cap from the air valve and release the air pressure by depressing the valve core.
3.
Remove the valve from the filler plug at the top of the strut housing.
4.
Fully compress the piston tube and fill the strut with hydraulic fluid to the level of the hole for the valve .
12-20-00 Page 12-13 Revised: February 28, 2002
5.
Remove the core from the valve and install the valve back in the filler plug. Torque valve 350 to 400 inch-pounds.
6.
Attach one end of a clean plastic hose to the valve and submerge the other end in a container of clean hydraulic fluid, making sure the end of the hose is below the surface of the 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 prolonged filling operations.
7.
Fully compress and extend the piston tube, thus expelling any air trapped within 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.
8.
When air bubbles cease to flow through the hose, compress the piston fully and remove the hose from the valve stem.
9.
Reinstall the valve core in the filler plug
— Note —
A completely empty strut will take 21 ±1 ounces of MIL-H-5606 hydraulic fluid.
10.
With the airplane still on jacks, compress and extend the gear piston tube several times to ascertain that the strut will operate freely. The weight of the gear, wheel, and fork should allow the piston tube to extend.
11.
Clean off any overflow of fluid and inflate the strut.
12.
Check that fluid is not leaking around the strut piston at the bottom of the housing.
13.
With the aircraft off the jacks, and the weight on the gear, visible strut extension should be 2.7 ± 0.25 inches.
FILLING MAIN GEAR OLEO STRUTS.
To fill the main gear oleo struts with hydraulic fluid (MIL-H-5606) use the following procedure:
1.
Raise the airplane on jacks as explained in Chapter 7, and place a pan under the gear to catch any spillage.
2. 中国航空网 www.aero.cn 航空翻译 www.aviation.cn 本文链接地址：西门诺尔飞机维护手册 simenole PA-44-180 AMM 1(29)
