The International Cessna^® 170 Association

Just wondering if anyone has replaced the rubber gaskets (?) on the pushrod tubes while the engine is still on the plane? Does the exhaust system and/or intake system have to be removed to facilitate the procedure. Can it be done without having to loosen the cylinder from the case?
Have never understood why these tend to leak since there is no pressure. The oil simply drains back to the sump from the rocker box. I suppose hot oil just hunts for the least microscopic outlet and goes there

I wouldn't bother. First remember, you have to remove the pushrod from the tube. After cutting of the old seal, you will ahve to work the new on through the thins slot between the tube and the lifter cover which may not even be possible. And surely by the time you did you/t be loosening the tube in the cylinder and causing a leak there.

This is why George was trying to develop a method of slitting the new seal and gluing it back together once installed.

If the leak bothers you so much, bite the bullet and buy the new style tubes and seals STC'd for the engine. Probably less work and hassle and it the leak will be eliminated.

I have had good luck stopping the leaks just by rotating the fingers of the clamp, or the screw part of the hose clamp, to the top. With them on top, you seem to have more even clamping pressure on the bottom where the oil runs. The clamps seem to create a slight pinch where they come together and could be causing your leak. I hope this helps.

Thanks for the input. I guess if I put the Real Gasket tubes on my tail springs would rust

Frank-
Years ago, I had leaking pushrod tube seals. I bought new seals and slit them with an Exacto knife. I slid the old seals up the pushrod tube and did not cut them off, just in case the experiment did not work. I cleaned the pushrod tubes very well to make sure no oil got on the face of the cut, then installed the seals and carefully Super Glued the slit back together, let them sit overnight to cure, then rotated the slit to the top and clamped them. Those seals lasted for years and did not leak. I think Arash's suggestion to rotate the seals and put the clamp tabs sticking up is a good idea.

George tried Richards technique and it failed. Could have been the glue George was using compared to Richard. What George found out was that the seals are a bit small requiring them to be stretched when installed. Of course after they are split, you need to stretch them to close the gap. Hard to do well I think and George found out and the glue did not hold.

George was trying some sort of Loctite rubber adhesive used in the aircraft industry as I recall. Richard used super glue with is cynoacrilate no matter who you buy it from.