I have a 2006 Nissan Sentra and replaced both front rotors n brake pads not less than 6mo. Ago. My passenger side was making grinding noise so I took a look at my brakes cause it sounded like metal on metal. When I took my brakes off seen they were gone n my rotor looked worn yet on the drivers side both looked fine. Can you tell me what can cause this?
I've seen this happen when the pads aren't aligned properly, sometimes from a missing shim or retaining spring. Basically the pad and rotor are in constant low grade contact and things wear really quickly as a result.
It's possible that you have a caliper that is stuck or simply not working or a bubble in the brake line/fluid. Bleed the brake line. If the fluid is brown, keep bleeding until it runs clear. If you see bubbles (or the fluid stops coming out for a few seconds) wait until you see all the normal brake fluid come out.
Don't forget to add more brake fluid (and try not let the line run dry, or else you will have to keep bleeding the line until you get those bubbles out).
Tip: I usually push a 3/8" clear vinyl tube over the bleeder screw so that I can better oberve the color of the fluid and see bubbles in the tubing as I bleed the brake line.
If one brake line has brown brake fluid it is getting over heated, probably due to a bad caliper. Bubbles may indicate over heating or a bad caliper as well but then again, maybe not. The brake line itself may be to blame, or there may be a small leak somewhere. Since brake fluid is corrosive to metal, look for any unusually rusty (nissans are notoriously rusty, so look for extra rusty) joints/unions in the brake line.