I was perusing r/AskAMechanic yesterday and came across a subject I’d constantly review with customers when I wrote service. Back in the day, when a mechanic recommended a brake service, it wasn’t uncommon to “turn rotors.” Now, though, hardly anyone does it…but that could change. Here’s why.

The brake lathe was a craftsman’s tool

Now, when I say, “back in the day,” I’m talking about the late 80s to, say, 2005-ish. I grew up in my dad’s shop here in the Midwest. He had a brake lathe, positioned in a fairly prominent spot. From my tiny young person perspective, at least, it was a giant bench setup with a huge Aamco blue plastic environmental cover.

The brake lathe machined a rotor’s surface so that a new pad could seat nice and pretty without hitting rust lips or run across warped rotor planes. Braking hard from high speeds, especially driving SUVs, minivans, or trucks – the heavy stuff – causes “warped” rotors. Drivers who have it typically complain of a shaking or wobbling sensation when they brake.

By machining the rotor surfaces, the technician could ensure a “like-new” brake job without replacing this component. So, the customer would pay for a new set of pads, a caliper service (cleaning the caliper brackets and lubricating the slide pins), and turned rotors.

Just like you don’t call for toaster repair anymore, we don’t turn rotors

The thing is, over time, rotors just got cheaper. At a certain point, then, turning used rotors became impractical from an operations standpoint.

After all, a thinner rotor face was more likely to warp anyway. And keeping a space-hogging machine that created tons of metal dust wasn’t all that ideal. 

By the time I started writing repair estimates, it was around 2002, our commercial parts account could win us a complete brake pad, hardware, and rotor kit for near any car for close to what we’d charge to turn. It just didn’t make sense to keep doing it the old school way.

To add to it, going ahead and replacing the rotors left the possibility of driver dissatisfaction pretty dang low.

Shops might go back to turning rotors…if they know how to do it

Interestingly, I wonder if some shops might dust off their old brake lathes and get to turning again. The tariffs could affect prices of all manner of car parts, even if it’s just a butterfly effect.

Of course, a lot of the “old ways” are simply a dying or already dead art.

I have a couple of examples. My dad used to bench rebuild alternators. Like the brake lathe, though, new and already remanufactured alternators just got much cheaper. As a shop owner, his time was better spent working on the business instead of rebuilding spent units. So he stopped doing it.

Until about five years ago, I worked at this same shop every day full-time. One of the major engine repairs we’d do is cylinder head gasket replacement. Part of the process is machining (or milling) the cylinder heads. You do this to make sure the new gasket set sits flush without gaps.

We knew one local guy who did it. He was already past retirement age when I started back at the shop after college. He operated out of a garage behind his house. His machine setup dang near filled the room, and he claimed to have spent gobs of money on it decades prior.

There are so few people, at least where I’m from, that still know how to do this stuff. So whether the “trend” of replacing brake rotors with pads will continue or switch back depends on who’s able and willing to turn them. Otherwise, folks might brace for more expensive brake jobs.