Brake rotor turning is a waste

So I replaced my front brakes, at 171,xxx. Tried once again like an idiot that forgot I’ve tried before to have my rotors turned. No need to waste money I thought. I don’t care if my front rotors are 20 years old if they spec and turn right. But once again I got bit in the ass. Take off after replacing everything, brake pedal feels like shit and like I need to shove it a mile to get anything done. Driving over 65 results in what I call the Yoo-hoo effect. As in I could tape a bottle to my steering wheel and it would get shaken good and plenty. Braking from high speeds results in the same shit only worse. So with only a week and a half on my pads I order a new set of rotors from Rock Auto. They came in this evening, swapped them out. Pumped pedal up. Started truck, took off down the road and it’s like it’s brand new again. All those problems gone. Brake pedal tight as can be and responsive. So for anyone reading this, when you do front brakes, I finally learned in my 35 years today, just spend the money on new rotors. I see a lot of post and questions about brake troubles, just replace the damn rotor and be done. Same goes for drums. I don’t care what anyone tells you! Ok my bitchin is done. Thanks for listening.

 

Not that I have rotors turned anymore either but who turned them?
Agreed if they spec they should work. I’ve tried turning my own but not on a brake lathe and failed.
Of course 6 month machinist at the time now with 30yrs in the trade I still wouldn’t do it.

 

Oreilly is where I normally go. Granted that may be part of the problem. But it’s been the same result any time I’ve ever tried. Everyone can’t be that retarded at using a lathe. It’s a pretty simple operation in the end. Of course you’re right, might wanna make sure it’s a rotor lathe I suppose.

 

As cheap as they are new,I have never had mine turned,its new rotors,and the cost of turning your old ones is not much cheaper than just buying new.

 

I've had my rotors turned for my 02 Grand Prix back when I was driving it. I paid under $20 for the fronts to be done.

 

Information I've come across(web search) claims rotors are not as thick as in the past in order to reduce unsprung weight - helps mfgs. more easily meet CAFE stds.
These thinner rotors supposedly don't turn as well as their ancestors - not as much to shave off as before.
Last time I had rotors turned was about the turn of the century - 1995 Isuzu Rodeo.

 

I ran a brake lathe many years ago and there are a few things at play.
The first is there's a limit to how much run out you can correct by removing metal.
Second, if you remove too much material the rotor will warp the first time it gets hot and at that point you would be better off if you had just replaced the rotor to start with.
Third, the alloy used in the rotor is critical. Some rotors just can't be turned and some are far more prone to warping than others.

The reality is that rotors have become fairly economical and it's generally easier to just replace them.

 

I'm at 190,000 and mine have been turned twice. It cost me about 1/2 of what one new rotor would cost each time. They work fine. I'll need new brakes again at about 230,000 and will need new rotors then.

 

It was 12 a piece for them to be turned. 47 with shipping for new ones. I wound up spending both trying to avoid one. Fml. I just think it’s a case by case thing but a lot of guys I have read on here complain after doing brakes of the same symptoms I had, and new rotors fixed it. Who really knows, we all just take an educated guess at the right thing, and hope for the best.

 

12 bucks is a small price to pay to learn a lesson.

 

Very odd. I’ve had the rotors on many vehicles turned without any issues. I’m wondering if the guy who turned them didn’t even measure or check the clearances before he worked on them. I’ve brought rotors and flywheels in and have been told they are out of spec. That’s when I bought new ones.

 

I watched him put the calipers on them to at least measure before and they were right at the edge of enough to turn. We both agreed it would be the last time they could be. The guy there seems pretty knowledgeable about it.

 

Having done that type of work in the past I can say that it isn't exactly rocket science but the outcome isn't as predictable as one may think.

The cost of brake rotors, adjusted for inflation, has come down over the years. It was significantly cheaper to turn rotors (and drums) 30 years ago than it was to buy those parts new 30 years ago. As the cost of replacement rotors came down, there was less incentive to turn used ones in an attempt to extend their service life.

Vented rotors (the ones with the hollow space between the two outer surfaces) are usually a little more amenable to turning than the solid types. Of course the solid types are almost always less expensive to start with.

The alloy used to make the rotor is important. Some suppliers get it right and make good rotors. Some suppliers just turn out a part that looks like a brake rotor.

An important consideration when deciding to turn or replace rotors is the amount of run out. (how far from being perfectly flat is the rotor surface).
Overall thickness is the pass/fail measurement after the rotor has been turned. If you have to remove a lot of material just to get the run out to near zero but the final thickness is still within spec, it's probably not worth turning.
Because they get paid to turn rotors and not to measure rotors, some shops will simply turn the rotor until it's flat, measure it to see if it's still within specifications and charge you for turning the rotor. If they had to remove a lot of material just to get it flat, even if it ends up being thick enough in the end; it's probably not worth putting back on the vehicle.

 

It is important to understand WHY brake shimmying happens.
When you understand this you understand why you don’t reface rotors.

Make sure you properly bed in your new pads and rotors or you can develop a shimmy again.

 

Wow. This is pretty ironic.
Just for the hell of it, literally yesterday I called up my local machine shop (just about the only one left in town...) to ask about turning my rotors.
My dad (being a frugal MF) always says "oh you should get them turned" whenever I replaced my rotors.
Kinda like a jab at 'us old people FIX our stuff, you youngins just throw it out and buy new'.

For years he says "you should get xxx turned" - rotors, flywheels, drums, etc.
I finally call a machine shop just to see the price and turnaround time.
The guy says "uh...yeah we can turn a rotor, but we barely do that anymore." I ask why, pretty much already knowing the answer. "Costs $45 to turn them, but sometimes you can buy a new rotor on Rockauto for $35. Just doesn't make sense. And not all rotors can be turned. If it's .450 right now, and the limit is .430, but it comes out at .420 when I'm done, then it will just warp again in a couple months."

At $45, it didn't make sense to me. But I suppose we have a high labor rate here. Turnaround time was quoted at 2-3 hours though
I think the issue here is - ROCKAUTO rotors are like $30-50. OEM rotors are much more expensive. If a OEM rotor from the dealer is...$120? and you want that "OEM quality" then it makes sense to turn them.
I'm not much of a sucker for 'OEM quality' but there have been times I've removed an old, beat-up OEM part, and it still looked better than new Raybestos, Moog, etc.

 

I have not turned a rotor in 30 years, replace is so much easier than dealing with a busy machine shop

 

Agreed. The economics have changed, it doesn't make sense to turn them anymore.

 

Do vehicle OEMs/Dealers pre-break in brakes before selling new cars?

 

totally...theres a reason rotors and drums are cheap...

 

Im in the auto inditray at the dealer level, or "stealership" haha! There is more to tuning rotors than putting them on a machine and walking away till it's done. If you take off too much to fast they will warp. If you dont manage the harmonics they will warp. The best way to machine rotor is on the car. That way if there are any variances it the hub or rotor hat they are accounted for. Machining on the car is the best way to do it. After machining rotor they have to be cleaned.
Most people dont want to someone to do the whole brake job. I get it. It a f-ing lot of money to pay for a brake job.