I have a 2002 Subaru Outback with a brake problem. Upon replacing the front pads, only the inner pad on each side was worn (down to nothing) while the outer pads were like new. The car has only 45,000 miles. This is the first time that these have been replaced. I'm thinking a bad master cylinder. Could this still be a warranty item? (since it probably never worked correctly) Is this difficult for a backyard mechanic? I've done master cylinders before, but not on a car with anti-lock brakes.

Look for brake pads grinding the brake rotor. It could be the "screamer" which is a small metal part that contacts the brake rotor telling you the pads are worn. Hopefully it hasn't ruined the brake rotor.

The brake booster is not connect to the wheels. More likely is that the oe or more of caliper slides are jammed with rust. If one usually the lower one) is jamming, the caliper twists on the rotor and the pads make all sort of rattling or squeaking noise. A worn wheel bearing allows the pads to be pushed away from the rotor: a mushy brake pedal or grinding noises are the common result.

you will need to push the piston of the caliper in using a c-clamp or suitable tool from your local parts store. Let me know if you need anything else.
Legacy, Outback & Baja

1. Loosen the wheel nuts.
2. Disconnect the negative battery cable.
3. Raise and support the vehicle safely.
4. Remove the tire and wheel.
5. Remove the caliper bolt. Do not disconnect the fluid line.
6. Remove the disc brake pads.

To install:

1. Installation is the reverse of the removal procedure.
2. Apply a thin coat of Molykote M7439 (part number 003602001) or equivalent to the pad clip.
3. Apply a thin coat of Molykote AS-880N (part number K0779YA010) or equivalent to the contact surface between the pad and shim.
4. Check the brake fluid level, correct as required.
5. Bleed the hydraulic system, as required.

6. 

7. 

try skimming your rotors

If light on yellow color I think It would be bark pads warning signal, please check brake pads not only outer inner too, because sensor fitted in inner pad some time outer pads not too bad but inner pads are worn, if not warn brake pads pssibly wiring faulty for brake pads sensors, if messege read color It would be low brake oil signal or hand brake signal, is this information helped you?

Good Evening, your problem is a normal wear and tear issue as that over time brake rotors can become slightly warped and the only time you feel it is when you step on your brakes. A normal rule of thumb on those systems is if you feel it in the steering wheel when you step on the brakes it is your front rotors, and if you feel it in your seat it is the rear rotors. Always change your brake pads at the same time you change your rotors to help the longevity of the brake pads. Glad to help.
Thanks,
Joey

The brake lights switch is located on, or activated by the brake pedal.

Seems it needs to be adjusted or replaced.

Good Luck

check your CV joints on your front drive axles. they will sometimes grind or click when braking or turning.

I have same problem; turns out all Honda Accords of this generation (2003-2007) do this. It has something to do with cold brakes and unseated pads, and the first time you stop from medium speed, you will hear a grinding, maybe from the back of the car (i think in my case).
My girlfriend looks at me, and we both wonder what it is, but it goes away in about 1 minute and I've realized it's only when the brakes are cold and it's not a problem. My brakes are basically ok, and there is nothing to fix...
I've done enough reading about this car on the internet, I feel pretty sure everybody's Accord does this, so I stopped worrying about it. A real problem, the sound would not go away as soon as the brakes warm up and seat the pads. After that, the breaks work fine.
If it was worn pads, the squealers will start up and not go away quickly. If it was a worse problem, the sound would grind continuously until fixed.
The two major problems with Honda Accord brakes are: 1) Brake judder at hi-speed medium braking. If you are going downhill, and just want to slow the car a little, if your rotors are getting worn, the steering wheel will give you feedback as brake judder. Hit the brakes harder, it will go away but it's scary and requires the rotors be replaced with a much higher quality rotor than came from the factory, and probably want to use ceramic pads (like Bendix CQ or CT). 2) Back brake pads wear down quickly. I read about this constantly with Accord owners, the EX back brakes are smaller rotors and pads than the front, but the electronic brake distribution system of the Accord will balance brake force between front and back, so the front pads will actually last longer than the back pads! This is very unusual but entirely normal for this car. Most cars are the opposite but that may change as we see new generations of cars with more evenly balanced braking front to rear. Be ready and watch your back brakes closely. Mine were toast at 30k...
I replaced my back pads and rotors, used cheapest new rotors I could find, and ceramic pads, and they have lasted considerably longer than the first set.
I now have 92k on my 2004 and the original front brakes are ready to be replaced. I replaced back brakes at 34k I think, and was very surprised they needed replacement at early, but the new pads have gone almost 60k, but look ready to be replaced sometime this year I think.
I have bad judder on high speed braking, but the pads are still ok in front. Rotors are **** in front and I'll replace with Centric Cryo-Stop rotors, they should last a long time as long as they get put on straight and I don't let anybody warp them with an air gun at the tire shop...
Two other more minor problems to watch for on this car: 3) Inner pads may wear faster than outer pads, because the caliper is on the inside, and forces the outside pads to contact the rotor after the inner pads are already braking. Seems like all Accords do this at least a little. The inner pads are not easily viewed without removing wheels, so it's hard to tell, but if your outer pads look like they are starting to get worn down pretty well, chances are good the inner pads are even more worn and you are ready to replace pads. 4) Pads may wear faster on one side of the car (fronts) faster than the other side. For example many people report driver side pads wear faster than passenger side. And the reasons proposed have to do with fast stopping for right hand turns or freeway loops. The car spends more time being braked in a right turn than a left over time.. But of course, on my car, it seems to be the opposite. The passenger side is wearing faster! Go figure..

use oem brakes,nothing else comes close,everything you need comes in the brake pads kit,rotors are better quality metal and more vents to cool,rember you get what you pay for