Originally Posted by Carl Froehlich
The most frustrating leak Iíve had was on the airspeed instrument glass face - it took a long time to find. Check for this by disconnecting and capping the static line going to the instrument.
There is a simple fix if this is what you have.
Now it make sense...those altimeter vibrators. If the needle sticks it prevents the meat lump sitting in the seat from tapping on the glass and breaking the seal.
BTW those vibrators in standby instruments in airliners are the most annoying sound ever!