Repacked slew cylinders recently, and I don't think most people know this, but it is very dangerous if not bled properly.  If you don't get out all the air, some air can get trapped in the cylinder.  The constant compression can heat the air, and you have hyd. oil in there as a fuel.  The result is the same explosion that occurs in your truck motor (a diesel bomb).  I know it's a random discussion, but as I was doing it I thought to myself 'I'll bet most people don't even think of bleeding these after they put in seals', so to prevent any injuries contact your manufacturer for proper bleed technique.