Turn rotor necessary?

[look 171]

Its that time again for new pads on my Cayman S. Rotors were new from my last pad changed. I have some free time in the up coming weeks so rolling up my sleeves soon. Over the years, pads were replaced on my other cars with both turned rotors and many times during my poor years in college, the pads got replaced no turning of any rotors. Tell you the truth, I can't tell the differences or jsut maybe I don't drive them hard enough? Thoughts? I just too lazy to remove the rotor and no one turns them now?

[afterburn 549]

If they are not warped (pulsating pedal), there is no reason to machine them true as they are.
Side note - I like ceramic pads as they do not dirty up everything so bad, and do stop the cars better

[look 171]

Originally Posted by afterburn 549

If they are not warped (pulsating pedal), there is no reason to machine them true as they are.
Side note - I like ceramic pads as they do not dirty up everything so bad, and do stop the cars better

I tried ceramic pads over the years on my 4 runner and wife's van. Can't tell the difference but maybe in a sport cars due to its lighter weight? Think they wear out rotors faster? I must say, Porsche's PCCB rotor and pads are provide awesome stopping power.

[David]

I never turn rotors anymore. They usually wear even and are cheap enough to replace when worn down. I usually get two sets of pads per rotor and this includes my Cayman which is about 90% track car now.

[Bob Kontak]

Originally Posted by afterburn 549

If they are not warped (pulsating pedal), there is no reason to machine them true as they are.

Correct, outside the rustbelt and salty air locations. No reason is too broad a statement to me. Normally?

Porsche uses good material that does not corrode easily which is another plus. However, refaced rotors will give a nice surface to bed the pads into.

There are several reasons in the rust belt to reface rotors. One is the outer rotor lip rusts and when you put new stainless retaining clips in for new pads the rust may rub on the retainers.

Also, I usually remove the caliper bracket and remove the rust on the retaining clip faces so they (and the pads) fit properly. Since the bracket is off the rotor can come off "easily" and I use a needle scaler to smooth the mounting surface for the lathe. There is usually plenty of rust scale to remove (mainly on the side walls up into the fins). I pay $12 per rotor to get turned.

[VINMAN]

It is almost impossible to find anyone to cut rotors around here anymore.

There's one guy on FB marketplace that does it out of his house.

.

[afterburn 549]

I would say buy a brake lathe as there are lots for sale on F.B.. I have seen them cheaper than 400!

[David Inc.]

If their thickness is still above spec, don't replace them. The rotors may even have depth indicators on them so you know when to replace them (little dimples in the face of the rotor that are at the depth of the spec, my wife's MB has them and they're kind of convenient).

A note on pulsing. The rotors aren't warped unless they've been on fire, it's just pad material. Try a pad bedding procedure to heat up the deposited pad material and scrub it off.

[VINMAN]

Pulsing can also be caused by a bent hub.

.

[look 171]

Anyone tried EBC pads. Any thoughts on Ceramic pads?

[dad911]

Originally Posted by David Inc.

If their thickness is still above spec, don't replace them. The rotors may even have depth indicators on them so you know when to replace them (little dimples in the face of the rotor that are at the depth of the spec, my wife's MB has them and they're kind of convenient).

A note on pulsing. The rotors aren't warped unless they've been on fire, it's just pad material. Try a pad bedding procedure to heat up the deposited pad material and scrub it off.

This. I didn't change rotors on my track cars unless they were below spec, or drilled and cracking.

Same with a pulsing pedal, it was always pad material on the rotor, never warped one.

[masraum]

I've had rotors (and even drums) turned several times. I've had economy cars where I could replace the rotors for $10-20, so I did that. I've gotten to the point that I generally just slap the new pads in because the rotors are worn smoothly and evenly. Even if they have some mild axial grooving, the new pads conform to those grooves so quickly that it doesn't seem to matter or affect performance.

What's shocking, is the range of prices of parts available for my '08 Box S. For the fronts, the price seems to always vary between the right and left which is extra weird.

On Pelican, the prices range from $42ea up to $337ea for the front rotors.

I know the stock is drilled. THere are also slotted available, and half a dozen brands.

I keep hearing/reading that ceramic is the way to go to reduce the amount of brake dust.

[fastfredracing]

I find the whole " rotors do not warp, its just pad material deposits " theory interesting .
As someone who has turned thousands of rotors in my life, I will wholeheartedly say, that rotors do indeed warp.
You can literally see the run out when you chock them up on the brake lathe, and bring the cutting bits close to the rotor surface .
I don't cut rotors anymore, but when I did, it was pretty rare for rotors to clean up without taking at least 5 thousandths off each side . It was not pad material I was removing, it was metal .

[masraum]

Originally Posted by fastfredracing

I find the whole " rotors do not warp, its just pad material deposits " theory interesting .
As someone who has turned thousands of rotors in my life, I will wholeheartedly say, that rotors do indeed warp.
You can literally see the run out when you chock them up on the brake lathe, and bring the cutting bits close to the rotor surface .
I don't cut rotors anymore, but when I did, it was pretty rare for rotors to clean up without taking less then 5 thousandths off each side . It was not pad material I was removing, it was metal .

I used to work at a FLAPS where we turned drums and rotors, and we frequently saw what you describe. I assume those were mostly under-braked cars, but not something like a Porsche. Of course, if you do hard braking on a Porsche, I assume it would be possible to warp them. There was NEVER any maintenance to our lathes. After the fact, I assumed that the issue was likely with our lathes or process for mounting.

[afterburn 549]

They definitely warp, but it, as you know, is very dependent on who made them.
The chineeease crap warps on deliovery.

[look 171]

I jsut look at Rock auto. They are stupid cheap compared to dealers. Anyone know anything about Powerstop carbon ceramic pads? For the same amount of money, Brembo is also what I was considering.

[cabmandone]

I have power stop ceramic on my son's Rav. The one thing I notice is a bit more brake noise. But he has four 10" subwoofers in the back so we can make that problem disappear.

On the turn v no turn, I'm in the no turn group as long as there's no odd wear on the rotor. If they're smooth, I'll slap new pads on and not think twice about it.

[Scott Douglas]

I'm old school and would have them turned, just to give the new pads a nice surface to bed into. If not turning them, at least scuff them up a tad as a shiny surface isn't going to bed very well, it'll just glaze over.
I hate it when the shop doing the turning just cranks in .010-.015" on the tool without giving any consideration to making the rotor last a little bit longer.

[Bob Kontak]

Originally Posted by look 171

I jsut look at Rock auto. They are stupid cheap compared to dealers. Anyone know anything about Powerstop carbon ceramic pads?

Dentist pal with a 2003-ish twin turbo 911 and a long amatuer Porsche racing history (Pal - probably more acquaintance - with Chuck Stoddard) said he got them for his early teens F-150. Powerstop rotors and those pads all the way around. Summit Racing.

Really nice was his response just now.

I'm embellishing/name dropping a bit to lend credibility, nothing more.

I would love to get them for my "new" 99 RAV 4 AND the calipers. How cool would that be?

[look 171]

Originally Posted by Bob Kontak

Dentist pal with a 2003-ish twin turbo 911 and a long amatuer Porsche racing history (Pal - probably more acquaintance - with Chuck Stoddard) said he got them for his early teens F-150. Powerstop rotors and those pads all the way around. Summit Racing.

Really nice was his response just now.

I'm embellishing/name dropping a bit to lend credibility, nothing more.

I would love to get them for my "new" 99 RAV 4 AND the calipers. How cool would that be?

Good to know, will give them a try. Worst thing it can happen is that they don't last as long as factory. Cheap and easy to install. I have had cheap pads over the years on other cars, they all seem to be ok, some fade coming down a long mt pass due to my doing to test thing out. Yep, I am thinking no turn rotors too.