I guess its possible to have a leak and never get to the pavement.. You *could* be leaking around the master cylinder, and it would pool up, or dribble enough to reach the ground...
Same for brake-lines... could be just leaking, barely..
Also... a small hole in a pressurized line *may* not leak unless you are braking.... which is why you *may* not see any leakage in your driveway, etc... you aren't using the brakes... a drop at this intersection, a drop at this light.... etc, etc..
Dunno..
I would check those caps/lines/valves for any type of moisture evidence, or staining from previous events..
ray
