well guys I got the New gm replacement rotors today,they are zinc coated with silver rotor paint where we have the rusting issues. these rotors are bigger than our stock rotors and will be out on the 08 models. ..the part number is 15856665... Now for you local guys the dealership is Barnes Wheaton pontiac,bring your cobalts in also, and if you want to they will put the cross-drilled slotted ones on for you but you have to pay a 35.00 difference,I did not go this route cause it would have taken a week for them to come in. They also told me to get back to them on how these rotors work, cause no one supposded to have these yet and if they dont work out I'll have to put the cross-drilleds on. hopefully the pic is okay, they are really nice rotors cant really tell the difference in size though

 

where you having surface rust problems or straight everything rusting problems?

 

Looks good.

Shoulda waited the week though.

 

Are they supposed to be bigger diameter wise or thickness wise?

 

hey Mike, how much did those cost you out the door? install and everything?

how much bigger are they then what the G5 has now?

 

Problem with drilled rotors though is it'll eat through pads faster. Eh

 

Small price to pay. We get alot of rain here and they work better in the wet. As well as the heat advantage.

 

hey, do us guys in the U.S get this also. I got suface rust and **** too. lol. how much did it all cost??

 

Damn these rotors seem to have better stopping power..as for the size I'm not sure,I posred up the part number so maybe Rally can answer the question as to where on the rotor that they are bigger,well now I'm gonna have to paint my rear rotors cause they look like total **** compared to the front ones

It cost nothing, my rotors were grooved and these are the rotors gm is using to replace our currents ones

 

where is this Barnes Wheaton pontiac you are talking about?? Carter Poco is being jackasses to me and my cobalt

 

Carter sucks.

Barnes Wheaton in Surrey

6280 - 120 Street
Surrey, BC, V3X-1Y7
Phone: (604) 594-2277

 

damn my rotors have some rusting and grooves too. i didnt know i could get them replaced for that!

 

Yes grooved badly, and rust when they get wet

 

1 part number for all 4 rotors?

 

just to let yall know these are new, my tech said,they just came out and that gm is using these to replace thecurrent rotors and hopefully all dealerships are up on these,I;m the first to put these on (kinda a guneia pig) lol.. they said if it does not work out they will know better and put the crossed drilleds on for me...makes me wonder if gm has done much testing on these new rotors yet!

 

wow my front rotors are rusted too and im no where close to a snow belt or salt at that but anyways my car has over 6k miles and they are grooved pretty bad, They also pullsate when you hit the brakes.. I don't know if the dealership is open on saturdays but im going to try this weekend.

 

Um... bigger rotors and same pads? ...and you have better stopping power? Doubtful. Still have the same braking surface area if you didn't change the pads.

The zinc coating is nice though. That's a good dealer.

 

dont want to phone them back and seem like a dork,but what part of the disc is bigger?, I dont have the old ones here so I have no way to measure.

 

I would assume a bigger diameter. I doubt they'd be thicker. But if you didn't change your pads, you still have the same braking surface. They're still a nice upgrade though (with the zinc coating).

 

Im callin dealer tomorrow. and checkin on this. I'll it up there A.S.A.P for this free ****. and i'll get drilled and slotted. if they say they can do it. or do they have to do it?

 

duh,now I fell dumb, of coarse more surface!

 

How can I tell if my rotors are grooved so I can have them replaced if need be?

 

pads were changed,got a friend at the dealership.

you would know.lol you would be getting a rather unnerving shake in your steeringwheel when braking

you will have to pay the difference on the crossdrilled as per my first post

 

You'd definetly feel it in the pedal if they were grooved enough. But easiest way is look through your rims and see if you can see a literal GROOVE worn into the rotor

 

when i need to get new brake bads im going to change the rotors to those they look realy nice. i also have the rust. but i only have 5K on my car so im not going to change them yet lol. did you do the rear also?