2003 Buick LeSabre Rotor Size Question

I just replaced rotors on a friend's LeSabre, after the install completed successfully we went for a test drive and the car drove great and broke smoothly without any binding. When we came back from the drive we noticed that we got brake rotors for the 15 inch wheels instead of the 16 inch wheels that are on the car. My question is other than the pad wearing differently will there be any adverse effects to driving the car with smaller rotors?



Staff member
I really doubt the rotors are a different size for the different wheels; and if they were, it would be pretty obvious from how the pads extended well beyond the rotor OD.
They are seriously different, the ones we purchased are 10" and the ones that were supposed to be on there were 11", we just didn't notice until it was too late and we were putting the old rotors in the boxes of the new rotors and noticed that they didn't fit in there. We're probably just going to get the right size rotors but I'm still curious if it would actually have any adverse effects other than pad wear?

Well the 10" rotors stop a full size lesabre with 15" wheels. The only reason they put 11" rotors on because they had the room to put larger rotors with the 16" wheels on and have a little better stopping power. The only difference that I would see if the stopping power.
As the pads wear, a ridge will form where to lining has no rotor contact. You may notice some symptoms when the rotor "grows" to a larger diameter during a time when it is at it's hottest, like going down a mountain.
Never thought about the caliper and brackett being in a fixed place Danica. There is a half inch that would not be touching the caliper at all. That to me would causes some problems in a few thousand miles. I think I would change out the rotors to be on the safe side.


Staff member
Wow, different size rotor amazes me! Talk about trying to cut pennies out of build cost... It sure can't be space in the 15" wheels, GM started using 11.75" rotors in 15" wheels back in 1965.
Indubitably a different part number for the 16" wheels, if the outer half inch of your brake pads are contacting air, would definitely wouldn't leave it that way. Should have seen that when you were installing the calipers.

Change it, right now!

I wasn't born paranoid but became that way with all this made in China crap, check the thickness of the new rotors, diameter, and even run a TIR test to make sure everything is correct. Your life depends on it!
I think the 15" was standard for the "Custom" edition, and the 16" was for the "Limited" edition...

The fact that the rotor is 1/2" smaller from the center means, that pad might be riding over the top edge of the rotor, which is not good......get the right ones....Since there was this mistake, make sure you eliminate the other potential ones when you put the correct rotors on....

Make sure the face of the wheel hub is completely clean of rust/corrosion using a whizzer.....apply the whizzer lightly to the inside of the new rotor where it mates with the hub.....make sure those sliding pins move very easily, lubricate if necessary......apply disc brake quiet to the back contact surfaces of the pads....install the pads in the correct position.....and torque the wheels in a star pattern at 100 foot pounds....
I meant in my previous reply that there would be a !/2" of pad not touching the "rotor". not the caliper. That would be some serious loss of stopping power. Need to proof read my comment a little better.
And one more thing. Don't be in such a hurry that you put one of the brake pads on backwards. Over 40 years of working on cars as a hobby and to save money and yes I did just that. About three stops and the rotor was grooved. The worst part was the pads had about 50% life left, and the rotors still looked OK. I just pulled the pads off to get a good look at everything. Anyway, I changed both rotors and the pads. Lesson learned :-[
Thanks to everyone for the great input. Right after I posted we decided to do it right and took everything apart and get the right parts installed and the pads are installed in the correct places. The car drove great and smooth, we took it for a couple of test drives around the neighborhood before taking it on the road and no problems.

Thanks again for all the help, this website is as always invaluable.