Alon A2 Oleo Strt

I stand corrected. I should be more careful in my wording.

John P.

Skyport has not met its demise. Vernon Gregory now has the stuff.

Kevin

Doing my shocks now. Replace those O-ring with 1 1/8 inch brake cylinder cups drill a #3 hole at the orifice, tape 1/4 28 thread install kit ... Oh plug the top hole. Those brake cupspred to seal better than the O-rings. Man, I miss those spring gear on my Alon 44F

Very odd. Are both pistons the same ?
Th piston must not have any holes in it to work as an oleo. There is air over the 5606. On the initial upward travel of the cylinder the 5606 transfers from the cylinder into the piston via the .070 orifice. This compresses the air in the piston but is not the principle shock absorbent. The main shock absorbent is the resistance to fluid transfer via the orifice into the piston. A tiny hole in the piston head will remove some small amount of shock absorbing but more importantly will cause 5606 to be ejected on every landing . A few landings and the oleo is no longer serving as a shock absorber.. On normal smooth landings this may be of no consequence but should you land hard the oleo will not be effective and the rubber donuts will transfer a large and possibly damaging jolt to the airframe. Not good !
The O ring oleo was a step backward for ERCO. The original rubber cup was a far more effective design altho it did have the requirement to use yet another fluid in this case being a J1703 spec. or today's DOT 3. Skyport sold a kit, SMK-61 to retrofit the rubber cup. Now available from Aircraft Spruce since demise of Skyport.
Was just checking on oleo topic and saw your post at this late date.
John
415C
s/n 4375

Doing some maintenance on the oleo struts which are on an Alon A2. I removed the piston from the assembly for a thorough cleaning and replacement of the O ring. While cleaning the piston I discovered that besides the orifice in the bottom of the piston there was also a very small hole drilled in the top of the piston. I assumed this was to slowly vent air out the top of the piston, but my AP is somewhat leary about the hole on top of the piston. After filling the cylinder with 5606, then forcefully moving the wheel into it's landing position, fluid squirts out the top hole of the piston. Is the hole in the top of the piston supposed to be there?