Glasair RG Gear Strut Servicing

It has been pointed out that our overhaul instructions are somewhat confusing and do not apply to landing gear struts that are being serviced while installed on the aircraft. Use the following procedure if you have not completely removed the struts from the aircraft or have your struts completely assembled on the bench but have no fluid in them

1. Pull firmly on the half fork so that the struts are fully extended.

2) If the strut is off the airplane, turn it upright with the fork or half fork down.

3) Fill the strut with Type 15 hydraulic fluid (Mil-H-5606) to the level of the valve stem. (Let excess fluid drain out.) After filling, let the strut stand for five or ten minutes and then recheck the fluid level. If the strut is off the airplane, tilt it to drain out some of the hydraulic fluid. The final level should be within 1/2″ of the valve boss, but it’s desirable to have the fluid level slightly below the valve so that the person pressurizing the strut will not be sprayed with hydraulic fluid.

Note: The Schrader valve may be removed from its boss on the trunnion cylinder assembly to facilitate filling the strut and checking the fluid level. Use Teflon thread sealant or Teflon tape when reinstalling the valve.

4) Thread the valve core snugly into the valve stem and pressurize the strut, preferably using nitrogen or, alternatively, dry compressed air. Initially pressurize the gear struts to the follows values:

• Glasair III, main and nose: 150 psi
• Glasair I/II/II-S/Super II, main: 110 psi; nose: 90 psi

Note: Slightly more pressure can be used in the nose gear to provide prop clearance under all conditions, and the main gear pressure can be adjusted to achieve the desired chrome oleo extension, which should be no less then about three inches.

Note: Because the volume of the cylinder is small, any leakage, such as from disconnecting the pressure fitting too slowly, may substantially affect the pressure in the cylinder.

Note: When checking the strut pressure during normal maintenance, the weight must be off the gear and the struts must be fully extended. Otherwise, if the struts are compressed, the fluid level will be above the valve and fluid.