mumpspro

Only 2600 miles on my car....just brought it to the dealer today because not only did I hear grinding from the rear brakes, they actually failed! Thank God the front brakes were sufficient to slow the car to a stop. The appt was for 10am this morning (I dropped the car off) and they still have it in the bay, so obviously they aren't done with it yet...hopefully I'll find something out in the morning.

Too bad this dealer has no hard info on the power steering recall (other than that there is one) or I could have them take care of that at the same time. Wish me luck!

ghostss09

done

CudaJoe

iTrader: (1)

guys, I had a thread with pics of all four of my rotors about 2 months ago. Well now I have replaced the rotors and pads at ~24,000 miles with the R1concept rotors and hawk pads. I will post pics of my findings for all those who dont have a clue whats going on with the rear brakes. It happens to ALL T/C cobalts. There are no exceptions.

Your best bet to fix this is to buy the R1concept rotors and hawk pads from the R1concepts thread. The total cost was 515$ shipped to my house. I then paid my cousin $60 to help me out and borrow his shop. so my total cost for the fix was $575 and it was WELL worth it. The rear rotors are a pain in the ass to replace though. We used the write up we found in the DIY section of this forum.

The inside rear pads were worn down to metal in the rear brakes on both sides. The outside rear pads looked brand new in the rear brakes (very strange). We noticed it was difficult to release the rear calipers from the rear rotor (it was like holding on with out the break even engaged. Possible issue)

THe inside of the rear rotors was completely destroyed. Our fix was to lubricate the sliding pin bolts and replace the rotors and pads, we also bled the brakes alittle bit. After we did the work, we saw that the e-brake seemed very tight when trying to engage it, (another possible issue).

A VERY special rear disc brake tool is needed to compress the caliper piston. We went to Sears to buy one and it was universal but it didnt work, Chevy made it so that you have to go to them to get the brakes done so it seems. We machined the universal tool to work with a saw, lol.

On the other side of the car, or the front rather... The front pads looked brand new and the rotors were in very good shape, almost new. So from what I can see, it looks like a buyer only needs to buy the rear rotors and pads for all four tires. so you could fix this for cheaper then what I did.
I got slotted rotors so thats why I changed all four rotors, lol. plus I got to look at the fronts very closely.

jboogie

iTrader: (3)

So, has the discussion been brought up weather it is better to go to a larger dealer or a smaller one?
getting ready to bring mine in and have a couple local dealers to choose from.

Permafried-

The step to do with cleaning and lubricating will solve the majority of issues people are experiencing with major scoring all over the rotor both inside and out. Since we all know the sliders are bone dry from the factory every TC owner should pay attention to this immediately! Since having mine done there is no more banding, grinding or grooving all over the rotor and my pads are still wearing evenly. This solved 95% of my problems with the rears to date.

Now that said I am CONVINCED my inbound caliper is contacting the inbound rear rotor, I have a 2-3mm gauge all around the driver's side rear rotor (inside) and no other banding, scoring or gouging is present so I can only assume:

1) My pads have a razor blade in them at that specific location
2) There is a diamond trapped in the pads I can't see (I checked for rocks, etc)
3) The rear caliper is contacting the rotor just enough to eat through that spot and once it's done it doesn't do it again (this groove occurreed less than 400km after a resurface)

Off to the dealer again, I refuse to replace the rear pads/rotors with anything until this is taken care of or I'm sure the same thing will happen.

CudaJoe

iTrader: (1)

ahhhh... okay, so your saying that the inside part of the caliper might have a casting issue where there maybe a contact point on the rotor. honestly I bet switching the rear rotors to the NAPA or R1concept premium rotors will help with that. They are a strong strength iron cast grade, G3500.

mumpspro

I got my car back from the dealer late last night. They stated that they just needed to grind some rust and dirt build-up from the rear brakes. Sounds odd to me considering the low mileage (2600 miles), but whatever...I'm going to keep an eye on it and if the rear brakes fail again, it'll go back...

CudaJoe

iTrader: (1)

they are pulling your leg. The only fix I know of is to switch to a stronger strength rotor. A mechanic friend of my dad's who owns a shop in NE stated this.

Permafried-

That's my guess. I took a look at them the other night and there seems to be very little clearance between the inbound caliper and the rotor. I noticed the trenches (yes trenches ) on my rotors came back after a single hard stop where I really had to get on the brake 'cause some jackass stopped dead in front of me while I was busting ass to merge with traffic.

I intend to take the car into the dealer and talk to them about it since there's not a chance this can be considered normal grooving at this point .

08SSTCRD

Any chance you could take a pic of the area in which you believe the rotor is touching the caliper??

There is no other way you could groove a rotor in one stop unless some hard metal was directly making contact with the rotor.

If that is in fact the case, it could probably be addressed with nothing more than a couple of very thin spacers between the caliper brackets and their mounting points, in order to better space the caliper assembly away from the inboard side of the rotor.

Permafried-

I'll put a note on my floor jack in case I swap my summers back on before going to the dealer, that way I won't forget to take one while the wheels are off . If you're looking at the caliper from the hub side it's on the trailing end (towards the rear of the car) right about middle of the rotor...that's about as best I can describe it without a picture.

There was a post some time ago by Krispy (think that was his username) who seemed to report the same thing with his rear calipers and I thought he had taken a picture of it as well. If I run my hand over the rotor (especially the passenger side) I can feel 3 distinct changes in how deep the grooving is (in the same spot) so I agree with your, short of metal on metal contact there's no way they grooved this bad in one stop unless the stars and planets aligned and I had two diamonds stuck in the exact same spot on both sides of the car .

MapOfTaziFoSho

Holy crap! Someone else has door alignment issues...

I really had no idea. This is my last GM product...ever.

08SSTCRD

You could go buy a Toyota, they are killing their owners as well as other innocent people.

And not only did Toyota cover it up, but now its been confirmed that cars that have had the recall done are still having problems with unintended acceleration.

The grass is always greener on the other side. I've seen both sides of the spectrum, don't be fooled.

1SLOLT1

UPDATE: took my car to the dealership today with 8700 miles on it the rear right rotor had a big groove on the inside. The service manager was cool he came out to my car and rubbed his fingers in the inside of the rotor and said we will take care of it so he took my car in and i went to work. He called about two hours later he said that they ordered new rear rotors and pads but they wont be in till next week and they took apart the calipers and cleaned and lubricated them and they should be fine like that till the parts arrive next week. I am glad they were cool cuase i went in there ready to chop some heads off if they gave me ****.

hunter19707

I took my rear tire off to plug a nail hole and I checked my inner pad, almost no life left, outer pad looks almost new! The rotor is grooved pretty bad. Rotors have been resurfaced once already. Looks like I'll be buying new pads and rotors at 17,000 miles.

Complaint filed!

Permafried-

You can replace all day, if you don't clean/lubricate the sliders it's going to continually happen. Check 'em and make sure they're heavily lubricated when you change the pads, that should solve that problem .

CudaJoe

iTrader: (1)

R1concepts rotors and hawk pads is the way to go I swear by it lol. or NAPA rotors. again, i'll repost when I check them at 5000 miles, that should be ample time to make new grooves.

Permafried-

Put 'em on mine and let me stop hard once....we'll know right away

Jalake

Agreed, Last GM product for me too

08SSTCRD

Exactly.

A lot of guys on here beat the hell out of their cars, and then they are surprised when something fails or wears out.

Well guess what, after doing some hard braking, the calipers heat up. Heat breaks down lubricants, and a lack of lubrication creates friction. This results in the slide pins not moving properly, and the calipers end up getting stuck. Then you wear your inside pad down to the backing plate while the outside pad hardly wears at all. Its not rocket science.

I swear a lot of people in here don't even understand how brake systems work. Proper maintenance is the key to longevity of any component.

hunter19707

I guess I shouldn't take it for granted that the dealer lubed the slide pins when they resurfaced the rotors and sanded the pads at 13,000.

08SSTCRD

I wouldn't.

Some of these dealer techs are flat rate hacks, they get the job done as quickly as possible without doing a thorough job.

Definitely worth pulling a rear wheel and checking.

Permafried-

Never assume the dealer will do anything they're not asked to specifically. That job is considered a brake service and they will likely charge you labour for that component of the job. I paid for it (first so it's on my record saying "look GM I'm doing everything I should" and second hoping it would clear up the binding) and so far so good .

If I'm not mistaken as a preventative maintenance item it's recommended the brakes be serviced (cleaned, lubricated, etc) once a year or every 20,000 miles or so?

The number of miles and time between maintenance will be different based on the conditions you drive in, and for those of us in winter climates with the road grime and freezing/thawing cycles the interval may be less. Performing the preventative maintenance can save you headaches in the long run.My pads are wearing evenly, 6/7mm remaining on each after 20,000km (miles..err....12,000?) so if all goes well they should last me a good 45,000/50,000 km if I keep on the maintenance schedule that I am.

That said I do still need to get the calipers checked out under heavy braking because that is still a problem and no amount of maintenance is going to solve it .

Permafried-

So for the time being I rolled around under the car without jacking it up (man the winter made a mess of my floor!) and got the best pics I could simply to demonstrate how the grooves are evenly spaces from the outside of the rotor on both in-bounds on the rear. Coincidence; I find that hard to believe, something has to be making contact because the rest of the rotor (inbound and outbound is perfect since being serviced). This is a temporary fill-in picture for 08SSTCRD who asked about the caliper but I haven't taken my wheels off yet (though I should):





On a side note when the wheels do get swapped I gotta do something about that rust....steel wool as a temporary fix until I can seal it .

CudaJoe

iTrader: (1)

There's your brake fix guys! lol.