Brake Job--turn the rotors or not?

[Matt Meiser]

I was always taught that brake rotors should be turned every time the pads are changed, but much of that teaching came from working at a regional chain auto parts store which offered that service as well as my dad--and usually when I helped him the rotors were in obvious need of resurfacing due to grooves, etc.

The rotors on my truck look great though the pads are getting close to their lower limits after 56K miles. Is there any real advantage to pulling them off for turning? Or should I just install new pads and go? Obviously the latter cuts several hours off the job pulling them, taking them in, waiting, etc.

[Lee Schierer]

As I understand it the main reason is that the new pads are flat and the rotors have grooves in them. Your braking power will be reduced until the pads and rotors wear to match grooves to get full surface contact. It also allows you to check for out of tolerance conditions and warping.

[Erik Loza]

I always have them turned when whenever putting on fresh pads. Erik Loza Minimax USA

[Joe Angrisani]

Always turn the rotors. It's a truing process midway in their life, and helps you maximize the life of the rotor. It also "resets" things as far as wobble or out of balance during normal rotor wear - i.e. no brake pulse 5,000 miles from now. There's going to be an area on the rotor that has worn deeper, and by resurfacing you spread the new pad's load over the whole rotor surface. If you just do a pad slap, the pads will quickly conform to the rotor, and the rotor's thinest area will wear faster under that high point on the pad. Finally, you can just about guarantee squeaky brakes if you bed a perfect pad against an irregular rotor.

[Ken Fitzgerald]

Matt,

We drop 800' in elevation between the area where I live in town and the rest of the community. My wife complained endlessly about the brakes on our ill-fated '83 full-sized Blazer we ordered. One of the grades downtown is an 11% grade. She fought the dealership with the brakes until the warrantee ran out. I took over and I always turn the rotors. She never complained about the brakes again until they needed normal replacement. When we bought a used Toyota 4-Runner to replace the Blazer, she insisted I do the brakes on it.

I always turn the rotors. Flat surface of the new pads against the recently turned flat surface of the rotor. It maximizes braking surface as stated earlier without waiting for brake-in.

There will be those who say it's not necessary but the conditions where I live? We live near the bottom where two river canyons converge and the confluence of two rivers. When you leave town, you climb 2000' feet in elevation over a 6 mile grade......3 miles 6%....3 miles 7%........9 semi-truckers killed at the bottom of that grade due to brake failures in the 30 years we have lived here. You don't want brake failures here!

[Carl Carew]

Would not argue with Ken's position based on his location, I live in Ocean county, highest elevation about 60 ft. I worked in garages growing up and am familiar with both drum and disk brakes. I do my own brake work and watch the condition of the pads closely. I generally replace before pads are entirely worn and carefully examine the disks. If they are close to original thickness and show no visable damage i do not have them turned. With my driving habits pads generally last 60,000 to 70,000 miles and disks show little wear. I am sure a lot of hard braking or operating in areas with steep grades would require more frequent maintenance and probably rotar turning or replacement. I would let examination of the brakes determine the path and after all they are your brakes I would not take a chance if there was any question I would replace.

[Bruce Page]

Rotors often get a glaze on them, particularly if they have been run hard. I always have them turned when I replace the pads.

[Stephen Cherry]

Check the price of new also- for my truck they are not expensive.

[Matt Meiser]

I did that on my wife's old Focus. They never wore too bad but needed turning due to warping. I kept a set in bags sprayed down with Boeshield ready to go. I just checked and a complete set for my truck is about $140 front and rear from Napa.

[Ole Anderson]

Ken, do you pull it down a gear on the big downhills, or just ride the brakes?

As to turning the rotors, I do it every pad change until they are too thin to legally have them turned. Around here it costs $12 per rotor or $24 per axle, half the price of the cheapest new rotor and half the price of decent pads.

[Ken Fitzgerald]

Ole,

I didn't down shift with my company cars/vans or with my personal vehicle, all of which have automatic transmission. I did downshift with my F-350 4x4 when I was towing our 9,000 lb. 5th wheel trailer. The pickup had a 4:11 rear axle and 5 speed manual transmission.

I never ride the brakes. I use a very intermittent pumping action. On my company cars, I often got over 65,000 between brake jobs.

My wife on the other hand, a born and bred flatlander, rides the brakes. Some of her cars (it was dependent) we have had, I was lucky to get 15,000 miles between brake jobs on her vehicle. She is not an aggressive driver.

[Mike Cutler]

Matt

It may be that you were taught that because it is a requirement in some states.
When I used to do brakes, and front ends, for extra $$$$, the state requirement, buried in consumer protection regulations, on a brake job was minimum 100% pad to rotor/drum contact. Less than this and the shop could held financially responsible for a brake system failure. The only way to guarantee 100% contact was to turn the rotors and drums. We never replaced just pads alone
As long as you still meet the minimum wall thickness, and run out spec's, there's no reason not to turn them unless it's cheaper to just replace everything.
However, many "newer" card and trucks are supplied with OEM rotors that are pretty marginal in an effort to reduce weight, and save money, so the OEM's may not be worth the cost of having them done.
The purpose of the turning is to ensure maximum pad to rotor, or drum, contact, allowing the pads to "bed in", and maximizing heat transfer/removal to prevent warping. On a small car you could get away with not turning them and let the pad bed itself in. If you use a truck like Ken does, for towing and such, in the mountains, it would be foolish.

[Harold Burrell]

OK...I'm going to be the one everyone gets mad at for disagreeing with the herd here, but here goes...

I RARELY get my rotors turned. Unless they're warped or horribly scored, I just replace the pads and go. In fact, I have even just replaced the pads when my rotors where scored (it actually increases your braking surface).

I've been doing my own brake jobs for nearly 30 yrs (man...that sounds soooo old, doesn't it?). Turning the rotors is fine. I'm not totally against it. However, whatever "glazing" you are trying to remove will be back the firsttime you really go anywhere. Not to mention the fact that turning (obviously) removes metal...which in turn thins the rotor...which in turn makes the rotor more susceptible to warping or cracking from the heat. You're often better off buying new.

Anyway...my $.02...

[Jeff Monson]

Always turn rotors for a proper brake job. New surface against new surface is the proper procedure. I have yet to find a brake mfg. to tell me differently.

[Dewayne Reding]

They should always be turned for best results. Some things have changed since I started professionally doing brakes 30+ years ago. Many of the modern rotors are truly designed to be disposable. They are too small in diameter and made of garbage iron. After resurfacing they are thinner of course, and much less ikely to last near as long as they did the first time. I always check price of new before I turn a rotor. Depending on the local rate to resurface a rotor, it may or may not make sense. The smaller and less expensive the car, the less likely that remachining will be a viable option. Many of the larger vehicles still come equipped with decent rotors.

[Brian Elfert]

There is a school of thought these days that rotors should just be replaced instead of turned. Locally, a number of auto parts places have closed their machine shops due to lack of business.

I took a class on air brakes last summer. This is for commercial vehicles, but the recommendation was to just replace drums and rotors instead of turning them. Labor costs for turning drums/rotors are high and just as important is liability for commercial vehicles. My motorhome with drum air brakes has drums that cannot be turned

[George Bokros]

As many have said it is better to turn the rotors to true up the surface plus the machine shop always mics the thickness and will tell you if they are too thin for safe use.

When we had drum brakes I always had the new shoes arc ground to match the drums and always had much better brakes. Not many people were aware of the arc grinding of the drums but the parts store I used recommended it so i tried it and they made me a believer.

I never put brakes on without turning the rotors, it doesn't pay.


George

[Wil Limanen]

I used to turn my rotors until I seen my brother-in-law's mini van front rotor. It broke right off of the hub part(turned into a 2 piece rotor). I always replace mine now with a new one. They get so rusty in this area due to the salted roads.

Wil

[Ole Anderson]

There is a school of thought these days that rotors should just be replaced instead of turned. Locally, a number of auto parts places have closed their machine shops due to lack of business.

I took a class on air brakes last summer. This is for commercial vehicles, but the recommendation was to just replace drums and rotors instead of turning them. Labor costs for turning drums/rotors are high and just as important is liability for commercial vehicles. My motorhome with drum air brakes has drums that cannot be turned

I would guess the machine shops were closed due to lack of folks rebuilding their engines, not due to lack of brake work. Engines last longer than the rest of the car these days. I just had a brake job at 56,000 miles on my 2002 Ford F-53 chassis motorhome. Disk brakes front and back. Rotors were turned with plenty of meat left but the pads were shot. I can't imagine that the labor to turn is more than the cost of new rotors.

[Rich Riddle]

There is a school of thought these days that rotors should just be replaced instead of turned. My motorhome with drum air brakes has drums that cannot be turned
Many of the new drums and rotors are produced in China to such thin tolerances they lack sufficient metal to be turned and still met minimal thickness tolerances; it's that way with many automobile drums/rotors as well. For those that can be turned, many times it's just as inexpensive to replace the units as turn them. If that's the case, why not replace them?

[Jerome Stanek]

I have had a new rotor that was bad and had they wanted to turn but said it was under warranty and had them replace it

[Ole Anderson]

I'm not buying the "just as inexpensive to replace as turn" argument. Where can you get new rotors for $12 each? I do buy the fact that in order to meet Obama's mileage goals manufacturers have to take every pound of weight out of the car and one way to do that is to make the rotors so thin that there isn't enough left to turn when the pads first need replacement. I doubt we can blame the Chinese for that, they just build them to the spec given to them by the manufacturer. And by the way, do any cars still have drum brakes anymore? Trucks, yes.

[David Weaver]

For you guys who have had yours reground, what is the total cost of a job with pads on either 4 wheels or two, and a rotor turn to go with it.

I'd get my rotors turned if there was a way for me to do it without paying someone to change the pads, too.

In theory, I will replace pads once without doing anything to the rotors, as long as they're in decent condition. And the second time replace the rotors, too, or have them put on a lathe. In practice, I've never had a car that got through the second pair of pads. Now that I have a wife doing most of the driving (I take public trans), I think the cars might be able to test that theory (her foot is heavier on both pedals than mine is on either).

[Matt Meiser]

Maybe not for the DIY guy doing his own work, but I can easily see it if you are having the work done. Even for me--its $90 difference. How much time is that worth? I'll get them turned later, but I can drop them off an pick them up when its convenient.

I have 4 wheel disc on my 09 F150, but the emergency brake is a drum brake inside the rear disc's hub.

[Rich Riddle]

I'm not buying the "just as inexpensive to replace as turn" argument. Where can you get new rotors for $12 each? I do buy the fact that in order to meet Obama's mileage goals manufacturers have to take every pound of weight out of the car and one way to do that is to make the rotors so thin that there isn't enough left to turn when the pads first need replacement. I doubt we can blame the Chinese for that, they just build them to the spec given to them by the manufacturer. And by the way, do any cars still have drum brakes anymore? Trucks, yes.
Well I can't get rotors turned for $12 and ordered different rotors (on clearance) from Rock Auto for $19 a piece. Even at full price they are about $28. Here is a link to a message board where an one ASE Service Manager discusses the topic. He claims you can get some rotors for $12, but that must be his cost. http://answers.yahoo.com/question/index?qid=20070825081741AAWOVWQ

To the next question, the new Ford Focus (at least in 2012) had rear drum brakes. Here is the link to the test drive: http://cars.about.com/od/ford/fr/2012-Ford-Focus-Test-Drive.htm The Honda LX and DX models have them. I know the Toyota Yaris had them recently but not sure if they still have them. The Jetta from VW had them until the beginning of 2012. When one does see them, mostly smaller cars use them on the rear brakes. My Saturn had them, but alas they are no more.

[Brian Elfert]

Many of the new drums and rotors are produced in China to such thin tolerances they lack sufficient metal to be turned and still met minimal thickness tolerances; it's that way with many automobile drums/rotors as well. For those that can be turned, many times it's just as inexpensive to replace the units as turn them. If that's the case, why not replace them?

My motorhome is older and was produced before a lot of manufacturing went to China. The drums are plenty beefy, but for some reason they are not supposed to be turned. The drums cost something like $200 or $300 each so they are not cheap. Luckily, the drums should last a minimum of 100,000 miles. I've put on about 30,000 miles in the 6 years since the drums were replaced so I'm good to go for a long time. What I have is a Q brake system.

[David Weaver]

I wonder of the jettas changed. I had a '00 a while ago and my wife still has a '04 jetta stinking up my garage. Both have disc rears (though the '05 and later redesigned models could have drums). For some reason, both of them went through rear pads fast, but neither has worn out a set of front pads yet.

In '02 or so, the dealer replaced the pads on the first one to the tune of $160 (back then, I didn't know any better). Last year, I replaced the rear pads on the '04 at 55k miles for $50. The dealer didn't put the '00 discs on the lathe or even suggest it, but if all VW dealers are the same as mine, that'd be the last place you'd want someone to shave the discs. They'd probably charge $100 to do it on the rears...and maybe would turn their nose up at that. I think the service managers there take a class in creative writing and apply it to the service tickets.

[Jerome Stanek]

Also when you do a brake job you should use a torque wrench on the lugs. If you torque to much on one side you can warp the rotor

[Greg Portland]

I'm not buying the "just as inexpensive to replace as turn" argument.
I think the equation in question is (2 X cheap rotor) equals or is cheaper than (1 X thick rotor + a turning).

[Chuck Wintle]

I have to agree with Harold...if the brake pedal has no signs of pulsing then slap in some new brake pads and go wit that. If otherwise the price of new is low compared to the job of turning them true again. On my Honda I never touched the disks until they to thin...new disks were about $25 each. just mt 2 cents.

[Joe Angrisani]

Also when you do a brake job you should use a torque wrench on the lugs. If you torque to much on one side you can warp the rotor

No you can't.

You can certainly do damage by overtightening, but there's no way it affects the rotor. Enough already with the wive's tales and shadetree mechanic opinions.

[David Weaver]

Joe, thoughts on aftermarket rotors? What to get? I'm a little bit wary about the prospect of buying $19 rotors.

[Joe Angrisani]

I never used aftermarket parts of any kind in twenty years at the shop (for most of you who don't know, I owned an independent Porsche-Audi shop for the better part of 20 years). I wouldn't put a NAPA part (any part) on a German car. If you want a laugh, compare a NAPA Gold air filter to a real German air filter for the same car, and look at the amount of filter media (easily 50% more on the German) and actual flow area (the perimeter seal foam spooges into the filter media blocking another 10%).

I did, however, use "OEM" parts. These are parts made by the original equipment provider, but not in factory packaging. For example, Zimmerman and Ate make rotors for Audi. You can buy them in a red and white Audi box, or you can buy THE EXACT SAME PART for less in a brown Zimmerman box. Same part inside. Very different from "aftermarket".

PM me about year and model and such, and we'll talk.

[David Weaver]

Well, I'm far from rotors at this point. I've been ordering only german parts for the wife's '04 jetta, most of them have come in audi boxes, except the coils. I don't want to jinx myself, but her car has been pretty good compared to mine, and I've needed only to replace a couple of coils and the rear brake pads and a waterpump (bought the part, had a mechanic do it after looking at the service manual). I can't find oil for a decent price around here (it's the 1.8T that I'm sure you are very familiar with) so I order pentosin from the same mail order place I get OEM. The service manual is a little annoying with "special tool needed. The coil tool is pretty lame - if the picture was better, I would've known better.

I doubt the mechanic likes it when I put the part (waterpump) on the seat, but he hasn't said anything so far and I like to know what goes in it.

That might sound like a lot of stuff for a car with 55k miles on it, but compared to the '00 I had, it's a fraction. I'd sum up the car as small, heavy for its size, bad mileage, expensive gas, expensive oil. Not a big fan.

[David Weaver]

Thanks for the tip on zimmerman, btw. Their rotors don't cost as much as I expected.

[Kevin Bourque]

I do my own brakes and I rarely have to get the rotors turned .
I usually just get some sandpaper and remove the glaze from the rotors and that works 95% of the time.
If I lived in a mountainous area or towed a trailer , sanding might not work.

[Jeff Monson]

I did, however, use "OEM" parts. These are parts made by the original equipment provider, but not in factory packaging. For example, Zimmerman and Ate make rotors for Audi. You can buy them in a red and white Audi box, or you can buy THE EXACT SAME PART for less in a brown Zimmerman box. Same part inside. Very different from "aftermarket".



Joe, that's the beauty of working with German cars, we deal with World Pac and SSF, great OEM parts without going to the dealer. Too bad we dont have these choices for the American market.

[Joe Angrisani]

.....I doubt the mechanic likes it when I put the part (waterpump) on the seat, but he hasn't said anything so far and I like to know what goes in it.....

Yeah, that's kinda like taking food to your favorite restaurant and asking them to cook your dinner. :p

We'd use customer-supplied parts, but if there were any parts-related problems, the customer paid the labor the second time.

[David Weaver]

Yeah, that's kinda like taking food to your favorite restaurant and asking them to cook your dinner. :p

We'd use customer-supplied parts, but if there were any parts-related problems, the customer paid the labor the second time.

Yeah, I was in a pinch (car gets warm fast when the water pump goes bad!!) and took it to pep boys (which is down the hill and not far away). I haven't found a good independent VW mechanic yet. I wouldn't have done that to a good independent mechanic, but pep boys charges as much or more than a good independent brand specific mechanic but I have no clue what they use for parts.