Originally Posted by 4ad
These seals wear from constant expansion and contraction during the heat cycles of the engine. If you compare a new seal to an old one you'll see the ridges on the base are worn completely smooth on the old one....no amount of hammering will do much good for long and MAY even pull the pushrod tube from the cylinder..
Besides...it's bad karma to hammer on an airhead.
How are you going to remove a push rod tube from the jug by resetting the seals? You're putting pressure on a non-fixed keeper that presses against the seal but holds it's position through friction. The tube doesn't move with the keeper because they're not firmly attached to one another and you're only moving the keeper 1/16" to 1/8" at most anyway.
Still, Your statement got me to thinking, so I went out to the garage and looked some R90 and R100 jugs. My conclusion is that it's simply not possible to hammer or press a push a rod tube, out of a jug, while the jug is bolted to the engine. Even if the tube was loose you couldn't do it because the push rod tubes are too long and even if they weren't, the lifters and cam are directly in the path of extraction.
I'm not making this up and I'm not trying to make this an argument... Please go look at some Airhead Jugs and explain how your scenario could be possible.
As an aside: Last Spring my pro Airhead mechanic and I both tried hammering a correctly installed SS push-rod tube, out of a cold jug and we found it impossible to do. Those SS tubes go in so darned tight
that you'd destroy the tube, the jug or both before you got em out. Also, with the spacers fixed
on those tubes, you cant reset the seals with em anyway.