FIXED see below post #6

2008 Outback AT.

Sounds like the brake wear indicator but pads are newish and plenty of meat left. Sound is not continuous when occurring but cyclical with the rotation of the wheels.

Happens when car has been driven and warmed up.

If I depress the brake pedal while driving, it disappears. If I lift the emergency brake lever up slightly while driving, it disappears.

Sometimes it starts after I've gone around a turn (as if something is tilting into contact??)

Sound seems to come from the left rear wheel.

When I pulled the wheel last time, I noticed a intermittent pattern of rust spots on the outward side of the rotor.

Rotors are original and have never been resurfaced (86k miles)

I plan on removing the wheel and pads tomorrow and cursing at it for starters. Any other suggestions?

Edited August 31, 201411 yr by brus brother

Recent pads? Did you get new slide shims for the bracket?

I bought a set a while back that had new shims and the tabs weren't bent quite right. They would rub on the rotor and squeal when the rotor got hot.

Pulled it apart and bent the little tabs back on the shims and it took care of it.

 

Another thing that can cause noise is the pad backing plate rubbing on the piston or on the fingers of the caliper. Some pads need a coating of anti-squeal compound on the back to keep them from rubbing against the caliper.

I had a similar problem of a squeaky squeaky sound. It went away on applying the brakes, or E-brake. Turned out to be a return spring on the E-brake that was rubbing.on something.

I had something similar recently.  I knew it was the right front wheel, but couldn't figure out what the source was. It only happened when turning left and only when going forward but not in reverse (while still turning left).  I eventually figured out the rock shield on that side (even though I checked it saw it wasn't touching the rotor at all) was rubbing just a bit.  I bent it out further and the noise disappeared. 

possible stuck caliper slides from age and road salts and if the calipers and brackets havent been aprt yet. It would be wise to clean and lube the slides and the shims.

FIXED

I have been using Autozone Gold Lifetime brake pads and recently noticed that they were slapping more paint on the pad's metal backing than usual.

When I tried to remove the pads, they were REAL tight in the metal guide plates. This probably distorted the metal enough for it to just touch the rotor.

I don't recall them being that tight when I first installed them but who knows... Old Timers Disease setting in!

Anyway, scraped some rust out of the area where the plates sit and then filed down the tabs on the pads themselves so they fit passively within the guides.

No more noise gremlins.

Edited August 31, 201411 yr by brus brother

Sometimes a little rust buildup on the bracket can make things squeeze together. I always try to remove the bracket and wire brush it to remove any rust/scale where the pads have to slide.

 

Glad you got it fixed!