The secondary seal is around the master cylinder's shaft. It is only supposed to keep the fluid from leaking out of that shaft. It normally has no pressure on it. However, when you pump up the reservoir, it gets that pressure applied to it, and if you pump it up too high, it will leak fluid.OKay, I'll take your word on itas I don't know anything about a secondary seal...
The military manuals say that you might get leakage around the master cylinder's shaft if you pump your brakes while the pressure is up, but they also say that it is normal, and not to worry about it.
-Chuck
