Shouldn't a brake specialist be able to prove with a micrometer that a rotor is too thin to be recut before insisting on new rotors?

Dear Car Talk

Dear Car Talk | Nov 01, 1997

Dear Tom and Ray:

When my grandson was visiting me during his last college break, the brakes on
his old Honda conked out. His dad wired money for a minimum brake job (what
father wouldn't?). But the young man called me in a panic when the brake-shop
mechanic told him he needed two new rotors because the old ones were "too thin
to be recut." When I insisted on seeing the Honda specs on minimum rotor
thickness, the "mechanic" did not know what I was talking about, but he KNEW
the rotors were too thin.

The cost of the job, including the new rotors, was more than the old Honda was
worth. So after more insistence on my part, the owner of the shop BORROWED a
micrometer from another shop, and reluctantly agreed that the new rotors were
not necessary. As an 80-year-old grandfather, I was happy to be able to help
out my 20-year-old law-student grandson (who, incidentally, did not inherit
much mechanical inclination from me).

Here are my questions: Shouldn't a reputable brake specialist be able to prove
with his own micrometer that a rotor is too thin to be recut before insisting
on new rotors? And if the rotors are not warped, do they have to be cut at all?
-- Hal

RAY: You're absolutely 100 percent right, Hal. This guy was obviously more
interested in selling rotors than serving his customers.

TOM: If the rotors are not warped, scored or pitted, they should be left alone.
You put in new pads and that's it.

RAY: If the rotors do show signs of warping or deterioration, then they either
need to be recut or replaced. And there are specifications that tell you
exactly how thick a rotor has to be before it can be ground down any more. And
yes, a brake specialist should certainly have the tools to make those

TOM: There are times when we recommend new rotors even if the old ones ARE
thick enough to be ground down. But that's only on cars where the new rotors
are really inexpensive (like on Volkswagens). And in cases like that, for a
couple of bucks more, why not get new ones?

RAY: But rotors for some older Hondas are quite expensive, so you did the right
thing, Hal. Now give this kid a good lesson about lawyering and demand one
third of the money he saved as a contingency fee.

* * *

What's one secret of financial success? Driving a used car! Read How to Buy a
Used Car: Things Detroit and Tokyo Don't Want You to Know. You can order it by
sending $3 and a stamped (55 cents), self-addressed, No.10 envelope to Used
Car, PO Box 6420, Riverton, NJ 08077-6420.

Get the Car Talk Newsletter

Got a question about your car?

Ask Someone Who Owns One