My brakes have made this groaning sound since I purchased it in September. Anyway, it sounds like I'm running over a brontosaurus everytime I let off the brakes while backing out of my driveway. It usually only does this the first time I drive the car for the day. Thoughts?
This repair DOES NOT apply to rear brake grunt/groan, pulsation or squeal.
This bulletin is being revised to add a model and to update the model years. Please discard Corporate Bulletin Number 00-05-23-001 (Section 05 - Brakes).
Some customers may comment on a moan type noise coming from the rear of the vehicle when applying the brakes. This condition may be more prevalent during city stop-and-go or mountainous driving situations. In rare cases, this moan type noise can also occur during the first or second application of the brakes when the brakes are cold.
As the vehicle slows down from 48 km/h to 0 km/h (30 mph to 0 mph), the rear moan type noise may produce a low resonating "hum".
This condition may be due to pad vibration being transmitted to the caliper assembly resulting in a low frequency resonance.
Replace the existing rear disc brake pads with a new rear disc brake pad service kit.
The new rear disc brake pads will reduce the vibration being transmitted to the caliper assembly. Refer to the Disc Brakes sub-section of Brakes in the Service Manual for replacement procedures.
It is only the rear brakes, I think hat bulletin nails it....
"In rare cases, this moan type noise can also occur during the first or second application of the brakes when the brakes are cold. "
I think that about sums it up.
Something that may be related; when I wash the car (usually just a quickie gas station wash....its cold here right now) I notice there is this dark crap dripped all over the inside lip of my rims. Its sort of a deep russet brown and sort of greasy. I only seem to notice it when the car has been wet, so I assume its just dirty water dripping from somewhere, but is there a possibiliy that it is important fluid leaking from something near my wheels and I only notice it when I'm doing a post-wash inspection?
To be absolutely certain, you should pull the wheels to inspect the caliper and hoses for leaks. What it sounds like is simply brake dust that didn't get thoroughly washed off. It shouldn't be any worse in the back than the front unless you're running semi-metalic or organic pads on the back, and ceramics on the front...or you have a sticking caliper. It may be time for a good inspection.
My car also does this mainly on damp mornings while backing up. It goes away within the 2nd application of the brakes. It'* quite normal in many cars because the dampness actually produces a slight rust over on the rotors, and once the brakes are applied, bye bye goes that little bit of rust, and the noise.