2 years ago I had my brakes/rotors replaced on my '98 Discovery. The ABS light has been on, since. Fairly recently, when the ABS light is not on (generally during the first minute of driving), my brakes 'stutter', braking power is severely diminished and I have to depress the brake pedal more forcefully in order to stop. Again, it only happens each time I turn the engine on, and within the first minute of driving. It's a little scary, but the problem isn't worsening in frequency or severity.

A mechanic looked at the brake pads/rotors which happen to be in great shape. The brake fluid is fairly brown, but the reservoir is full. Is there air in the brake line? Should I consider bleeding the brakes, next? Are the brakes about to fail completely? I'm concerned about the safety of driving this vehicle.

Any advice is appreciated.

K