tl3097flnkr

I have a 08 tl 7600 miles. Today I noticed grooves on one of the rear brake rotors. There are quite a few grooves which I can see and feel with my finger. I don't drive rough and am gentle on the brakes. I did recently make a panic stop from 50 mph I don't know of that affected anything. I haven't noticed any loss of braking power and there is no noise (atleast I can't hear any with driver side front window down)
what could be causing the grooves? Do I need to take it to the dealer? What do I need to know before taking it to the dealer?

Turbonut

iTrader: (1)

Groves can be from rust/debris that is trapped under the pads, or from a pads that has been worn down. If the car has only 7,000+ miles and you're the OE owner, there shouldn't be a problem like that. Make certain the wheel/tire can be turned as easily as the other side when off the ground, just to make certain no mechanical problem.

tl3097flnkr

Yeah I am the orig owner, the pads shouldn't be worn out unless one panic stop causes the to wear that much-which I believe will not be the case. I am afraid it may not be a stone or something that got trapped between the wheels and the pads because of the number of grooves. If there was one groove it could have been something hat got trapped but I have grooves over almot the entire rotor and they seem to have shown up within the last couple of weeks.

tl3097flnkr

Is it normal for brake pads to make a slight sqealing noise when the car has been sitting in 28 degree F? it happens only when reversing. Also how normal is it for a car with 7600 miles to have grooves on the rotors? If there is in fact a issue will Acura cover it under some kind of warranty? I know there is no warranty on brakes because they are wear and tear items but they shouldn't groove so soon right? Any idea what would cause multiple grooves on the rotors?

Turbonut

iTrader: (1)

Here's some reading:
https://acurazine.com/forums/3g-tl-2004-2008-93/weird-noise-reverse-553213/
https://acurazine.com/forums/3g-tl-problems-fixes-114/rotora-pads-rotors-screeching-reverse-743800/

tl3097flnkr

Thanks turbonut. That was useful...the noise disappeared after I drove It around for sometime...still worried abt the rotors though...

Majofo

Sounds like your rear rotors are warped.. it's a heat issue. Getting them lathed / turned is the cheapest route but watch them as they will warp much easier after they have been turned. Do a proper bed in once you get the rotors addressed. What type of pads are you using?

ChicagoNick

both rear rotors have substantial grooves(just as the OP explained). The rotors do not look "smooth" like the fronts.
I thought there was a problem and have gotten 3 different opinions.

1) Acura Dealer: Nothing is wrong with them. It's normal.
2) My Friend Who Buys/Sells Cars For A Living: So long as the car is braking evenly and not making noise, they're fine.
3) A Mechanic I Know: Says they're fine, also.

Apparently this happens when the car sit on the lot for awhile prior to purchase. When you drive around and brake 'normally' the rear brakes don't work very hard. When you have an emergency stop, the debris on the pad (which accumulates from sitting/lack of use) scratches the rotors. So long as the car stops properly and is absent of noise or pulsing your rears should be fine.

Personally, I can't wait to replace the rear rotors... mine look like garbage.
I figure slotted rotors will help eliminate this debris that causes the rotors to look like that.

Majofo

Spot rust may cause scratches along the rotor which can be sanded down but uniform grooves from the hub center to the edge of the rotor are heat related and the rotors need to be cut / turned / lathed if possible to return the smooth surface.

If you leave the car parked for an extended time in a moist environment you should take the wheels off & knock off the rust with medium grit sand paper & brake cleaner, then let the pads do the rest followed by bed in.