2. If from B , it may be the damage of the O-ring as showed as b in slide 2 or the loosen of oxygen bomb head . Replacing the O-ring or re-tight the oxygen bomb head.
3. If from C , it may be the damage of the upper pad or lower pad as showed as c in slide 3 .Replacing the upper pad or lower pad .
4. If from D, it may be the problem of the big O-ring , replace it .