Piper SEMINOLE PA-44-180, Maintenance Manual

Page: 78 / 881

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 27 +/- .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. Unless already done so, remove the cap from the air valve and by depressing the core, relieve the air
pressure.
3. Remove the valve from the filler plug.
4. Fully compress the piston and fill the strut with fluid until it comes level with the hole for the valve
5. Remove the valve core and install the valve with a torque of 350 to 400 inch-pounds.
6. Attach one end of a clean plastic hose to the valve and submerge the other end well into 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 prolongs
filling operation.
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, fully compress the piston and remove the hose from the
valve stem.
9. Reinstall the air valve core.
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 with air to 200 psi.
12. Remove the aircraft from jacks and check strut exposure for 2.6 +/- .25 inches.
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
1 2 - 2 1 - 0 3
Page 12-06
Revised: May 15, 1989
1D6
PIPER AIRCRAFT