I started hearing the warning buzzer going on my Mom's '98 Legacy L wagon with 120k on it a few days ago. about 10,000 miles ago I replaced the pads with semi-metalics and went with Brembo rotors. It was sound was only coming from the drivers side and there was allot more brake dust on the wheel cover on that side?? When I pulled the wheel I saw there was nothing left on inboard and out board driverside pads. but the pass. side pads were only about half way worn down??? when I did the braked 10,000 miles ago I flushed and blead teh brakes according to Endwench mag. and the sides and calipers both move freely. Is the drivers side brake hose collapsing???

Step on the brake fairl hard with a friend watching the hose. If it swells that's the rpblem. It might just have been wear on the rotor if the pistons are free.

Watch the brake with the wheel off while a friend applies the brake. Do both sides apply and move evenly?

When you spin the wheels after application does the caliper free right up?