One son is having alternator problems and another calls to report a brake problem...

This is an ABS car. He describes additional travel distance before reaching that point where the pedal "firms up" and the brakes are being applied. He said initially there was a hissing or gurgling sound, but that is no longer occurring.

He says the pedal is not pulsating and the car is stopping fine, but I am sure he is not pushing the envelope on speed or stopping distances.

I am wondering if one of the chambers on the dual master cylinder has lost its sealing power and it is therefore using only the remaining one? I think I can check for that by removing one line at a time and installing a plug on that outlet and see if one of them is unable to hold pedal pressure.

Any other ideas on what might be going on?

Thanks, Randy