Deep grooves on inboard sisde of rear rotor

[geocor]

I have a 98 Camaro 46k on the ticker ,the pads are not that badly worn on the rear but for some reason the inboard rotors seem to be badly grooved.They also seem to be loosing their surface in some areas .Anyone know if that year had trouble with rotors being defective?Its a weird problem because after I took off the pads they seem to have a lot left on them, but appear to be harder than the rotors in certain areas & digging grooves in them.Anyone else have this happen,this is a first for me ?

[geocor]

PS: its just the inboard side of both rear rotors!

[Loochy88]

only times i have ever seen that is from the pads wearing all the way down and digging into the rotors. maybe it happened with a previous set of brake pads. try getting some cheap autozone rotors and see if it happens again.

[geocor]

These pads are the originals (bought the car new) & have plenty left on the inboard & otboard sides!But its obvious that the inbord pads are harder than the rotors,strange but thats the only thing i can figure out.Wonder if anyone out there knows what I'm seeing?

[94Redbird]

I had the same thing happen to me not too long ago where one of the brake pads gouged a ring in my rotor. I just changed the rotor and pad and it was fine after. My guess is there was something in the pad that didn't want to wear down because there was actually a line across it that wasn't worn down as much as the rest of the pad.

[geocor]

Sounds like the problem I'm having,thanx for replies to all!

[IceBird]

If you only have 46K miles and bought the car new then it should be under warrinty. If the brake pad was faulty then you should be able to have everything replaced for free at the dealer.

[BobbyZ72]

That happend once on my car, but it was the front disks. When i first noticed it i didnt know where it would have come from, then i got to thinking about it. About a month before i went off road in some mud. My guess was dirt and grit maybe some small fine stones got stuck between the pad and rotor. I only drive my car on the weekend so things take longer to show up.

[geocor]

Warranty? The car is 7 years old+ ,GM has a 3 year bumper to bumper or 36Kmi., Warranty that year & even now I believe.Don't even know ,maybe wear items like brakes might have been excluded.As to driving never took the car off road just normal driving. & man I mean big chuncks of metal looked like it came off inboard side of just rear rotors!Some said it could be a caliper (they seem to slide well) sticking ,but why would the both in & outboard pads be in good shape, meaning a lot of materiel left on both?Just deeep groves in the inboards because of ,I'm thinkiking defective rotors.

Anyway problem was solved, bought "Gren" brand rotors at a local small independant auto parts store for 21$ each.Yes I know they're Chinese made, but Auto Zone,Napa,Advance, Pep boys wanted around 65$+ for each!Anyone ever get this "Gren" brand before?They say they meet all SAE specs for these rotors.They could'nt be worse than the original GM ones anyway!

[camaroman1181]

how did you originally heat cycle the pads when you first got the car? if you dont properly break a brake pads in, the compounds that make up the pad do not settle correctly. this leads to the mixture not staying completely homogeneous and causing some of the like materials to clump together. this will create hard spots within the pad itself. these hard spots will cause increased brake noise, and in some cases, groove the rotor. I'm guessing that is what happened here. this is normal cause most people do not properly break their brakes in when they first put them on. i highly doubt the dealer broke them in for ya either.

[geocor]

I've had lots of cars new & used with disc brakes all around & never had this problem before.I drove the car sensibly ,never made hard stops from the point it was new.Did just as the owners manual said to do.I've got a '03 C5 that seen more hard stops than this car & don't have this problem.Believe me the car was "adult" driven (very gingerly) & only driven by me.Why are'nt the front rotors (which probably take 75% of braking brunt)not in the same condition.

No,its not the way I drove the car,because I've had ,as stated many vehicles, probably a lot more than most on this Forum (I'm a lot older than most if not all of you), & none had this problem.The rotors just look like the surface had bad casting & is chuncking off,showing a lot of rust on the braking surface,& a ton of ridges on the pads because of this chunking & grooving.

On the new Gren rotors I bought it states to go easy on them for the first couple 100 mi. or so. & thats what I'll do.Anyway the car is a DD so I never "hotrod" it,got the C5 for that!

[Dominic]

you just got some sand on one of the rear pads at somepoint, or grit, and it gouged it. You're fine [img]smile.gif[/img] Good deal on the gren rotors.

[IceBird]

I dont know man he says there is chunks and stuff missing. That sounds like more that heavy break use...

[geocor]

I highly doubt it, the cars been babied, even rarely driven in winter.A friend of mine who's a metalurgical engineer saw the rotors & commented that it looked like defective grain structure in the processing of the rotors metalurgy.He worked in a steel casting & rolling facility for 20 years, so I think he would have some insight on the issue.Like I said the front rotors wore nomally.Lets face it for chuncks to be comming off the rotors inside surface ,thats very abnormal,even if some debris got on them.Besides the pads should wear before the rotors!

If its heavy brake use ,which I know its not , than why is there barely any wear on the pads?Just grooving on the inside due to the rotors. The inside pads had so much left on them, I just filed down the ridges & reused them.the outside were little wear & reuse those too!

[ July 20, 2005, 06:05 PM: Message edited by: geocor ]

[geocor]

BTW moderator Dominic ,great looking Camaro!!