YACT - Rear brake rotors out of spec?

[gregshin]

I went to inspect my rear rotors....the shop told me i needed to change my rotors...they said i can no longer shave and turn my rotors cause they are out of spec...i looked at my rotors and they are fine...you think the shop is trying to scam me?

 

[Eli]

Most likely.

Have you had them reworked before? If so, how many times? If you have indeed had them machined because of deep gouges, then it's possible.

How do you even know they need it? Are they warped or scored?

 

[Luke1]

They mean they are too thin to to shave or turn. They will re- warp very quickly because of the lack of integrity. It's nothin about how they look to you.

 

[gregshin]

hmmm...i went there before for my last oil change and asked to check my rear brakes...they guy said i have 40% of pad left...now 3000 miles later i need new rotors? i thought that was kinda strange?

 

[Luke1]

Pads aren't rotors. You could have brand new pads on wore out rotors.

 

[Xionide]

Where is NFS4?

 

[Eli]

Go to a different garage and get a second opinion.

 

[Jzero]

Did you ever have the rotors milled before? What kind of car? Ford puts "disposable" rotors on the Focus (www.fordfocusbrakeproblems.com) which are always out of spec...

 

[Soybomb]

You probably won't be able to tell if your rotors are fine by looking at them, you need a micrometer to measure thickness. If they're too thin, they can't be turned. How much brake pad you have left has nothing to do with your rotors.

 

[MichaelD]

Originally posted by: Soybomb
You probably won't be able to tell if your rotors are fine by looking at them, you need a micrometer to measure thickness. If they're too thin, they can't be turned. How much brake pad you have left has nothing to do with your rotors.

Most complete and correct response. The above is 100% correct. However, they might be scamming you. Usually, right on the rotor is stamped it's minimum acceptable thickness, in mm. you need a micrometer to measure the thickness. Turning or shaving down the rotor to smooth it reduces the thickness quite a bit, especially if the rotor is heavily grooved.

 

[gregshin]

im gonna take it to another shop for a 2nd opnion

 

[Quixfire]

Originally posted by: Jzero
Did you ever have the rotors milled before? What kind of car? Ford puts "disposable" rotors on the Focus (www.fordfocusbrakeproblems.com) which are always out of spec...

That's not true. The problem stems from a balance of pad material and rotor thickness for weight savings and dust/noise concerns. Most likely the pads are a very hard material to reduce noise and dust but you trade off wearing the rotors at a faster rate. The focus is not the only car with this problem, Windstar, Contour, and Cougar have this problem as well. It also on other manufactures cars, Chevy Blazer/S10 have very short pads life. The W-body GM vehicle needed rotors at almost every brake pad service.

The commonality with this pattern of premature wear is parking brake usage, all most every vehicle I have seen with worn front brake pads also have rear brakes out of adjustment causes the front brakes to due more than 60% of the braking. I always recommend using the parking brake, because modern rear brakes will not adjust without the use of the parking brake, including some rear disk brakes.