[Dunc]

Have an 08 Boxxer and was doing some service on the rebound side and changing the oil in the lowers. Since putting it back it needs more air than before. I never wrote my old pressure down but I was around 70 - 80 lbs, I'm 215 lbs. Now I need to put in around 130 lbs. Thinking that I need to service the o ring on the air piston as I guess the air is slipping around and charging the whole stantion.
Just looking for some confirmation from others.....

 

[Mr Jones]

Is it losing pressure at all?

 

[Racebike]

I have seen a few with worn o-rings that leaked air into the outers. And some that don't equalize the pressure well (grease/oil sludge caused problems with premature bottoming out as well). A thorough clean and rebuild cured those problems.

Maybe it was really sticky before and now is super smooth = higher pressure?

Another thing may be the outers. When putting the fork together you can install the bottom bolts halfway, depress them and push the fork together before tightening them.

This almost puts a negative pressure in the outers and makes the fork very nice over small bumps (at least a good placebo effect).

The point is, that sometimes the outers have a small air charge that will have an effect on the air spring.

 

[Dunc]

It is holding the pressure. I do compress about halfway when putting on the lowers to keep the pressure down. Gave the lower a check last night and did get a burp from the bolt so the air piston o-ring needs a check i guess.
Must be missing the point, if the ring is passing air then I need to put more in but it is the pressure not the volume of air. So why does 130lbs keep the fork at the correct sag and doesn't blow through its travel if the pressure is being equalized? did I turn the left leg into one big air chamber? (so I can pull the piston and save weight?....kidding)