Rotor Question?

MarcusMcRae · **Posted:** Wed Mar 08, 2006 3:09 pm

So the STi has a rotor service limit of 2mm. I am pretty sure I have worn almost that much off. It is time for new pads and I am trying to decide whether to say screw it and turn them or buy new ones. Any suggestions?? Funny thing, they list the service limit for the pads as 1.3mm.

BretLuter · **Posted:** Wed Mar 08, 2006 3:47 pm

If it's 1.3 or 2.0mm, then you must be talking about the max that can be shaved off the rotor (???)...

Most rotors have a min. thickness measurement that you cannot go past. Every time I've had rotors turned (it's been a couple of years...) they are VERY careful to check the thickness to make sure they will not be going past that min. thickness.

I guess you have to figure out how much new rotors cost vs. resurfacing the old ones (if they can be cut)- then decide.

FWIW, if they are not scored or otherwise damaged, you don't have to turn them. In fact, many people recommend replacing only pads OR rotors- not both at the same time.

Bret

MarcusMcRae · **Posted:** Wed Mar 08, 2006 4:02 pm

Yeah, they are 30mm thick and they say that only 2mm may be worn before you need new ones.

They look fine. I was under the assumption that you should turn rotors when you get new pads.

Bernie Baake · **Posted:** Wed Mar 08, 2006 4:14 pm

stoptech has massive info on what your asking and more at
http://www.stoptech.com/tech_info/wp_bedintheory.shtml

Aaron Buckley · **Posted:** Wed Mar 08, 2006 4:18 pm

MarcusMcRae wrote:

Yeah, they are 30mm thick and they say that only 2mm may be worn before you need new ones.

They look fine. I was under the assumption that you should turn rotors when you get new pads.

It all depends upon how much new rotors cost. Even on my Celica, which is by far one of the easiest cars on brakes I've ever owned, I always prefer to replace rotors instead of turning them.

Now, with some 3 piece rotors that cost big $$, then turning might be the answer, as long as they are within the service limit.

Here's how I would approach your situation: If you run you finger across the rotor from the inside to the outside and it's smooth across without any 'lips' from where the pads never touch, then as long as you have no pedal chatter, just slap on pads and go. If you have a 'lip' either have them turned (within tolerances) or replace. - AB

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

Mine are pretty worn, too - probably right around that limit. You might find some info on this is the brake forum on nasioc. I'll go look for something...

Kevin Allen · **Joined:** Thu Aug 28, 2003 6:42 pm **Posts:** 3479

Oh, yeah - and the cheapest rotors I've found are about $750 for a set of 4.

MarcusMcRae · **Posted:** Wed Mar 08, 2006 4:30 pm

Aaron Buckley wrote:

MarcusMcRae wrote:

Yeah, they are 30mm thick and they say that only 2mm may be worn before you need new ones.

They look fine. I was under the assumption that you should turn rotors when you get new pads.

It all depends upon how much new rotors cost. Even on my Celica, which is by far one of the easiest cars on brakes I've ever owned, I always prefer to replace rotors instead of turning them.

Now, with some 3 piece rotors that cost big $$, then turning might be the answer, as long as they are within the service limit.

Here's how I would approach your situation: If you run you finger across the rotor from the inside to the outside and it's smooth across without any 'lips' from where the pads never touch, then as long as you have no pedal chatter, just slap on pads and go. If you have a 'lip' either have them turned (within tolerances) or replace. - AB

The rotors seem to be in good shape. There is a small lip on the very edge of the disc. I can get some decent aftermarket rotors for about $550. The stock ones are almost $1000. They are one piece rotors.

MarcusMcRae · **Posted:** Wed Mar 08, 2006 4:31 pm

Kevin Allen wrote:

Mine are pretty worn, too - probably right around that limit. You might find some info on this is the brake forum on nasioc. I'll go look for something...

I tried searching nabisco and did not find anything useful. Post a link if you find something good.

Rich Anderson · **Posted:** Wed Mar 08, 2006 4:37 pm

MarcusMcRae wrote:

The rotors seem to be in good shape. There is a small lip on the very edge of the disc. I can get some decent aftermarket rotors for about $550. The stock ones are almost $1000. They are one piece rotors.

HOLY CRAP! I got custom two piece rotors with aluminum hats and Wilwood HD directionally vaned rotors made to my specs for that price. Replacements are now only $250 a pair since I never have to buy the hats again. There is NO good reason I can think of to buy OE rotors at that price.

MarcusMcRae · **Posted:** Wed Mar 08, 2006 4:54 pm

Rich Anderson wrote:

MarcusMcRae wrote:

The rotors seem to be in good shape. There is a small lip on the very edge of the disc. I can get some decent aftermarket rotors for about $550. The stock ones are almost $1000. They are one piece rotors.

HOLY CRAP! I got custom two piece rotors with aluminum hats and Wilwood HD directionally vaned rotors made to my specs for that price. Replacements are now only $250 a pair since I never have to buy the hats again. There is NO good reason I can think of to buy OE rotors at that price.

Those prices are for all four rotors.

Rich Anderson · **Posted:** Wed Mar 08, 2006 4:59 pm

MarcusMcRae wrote:

Rich Anderson wrote:

MarcusMcRae wrote:

The rotors seem to be in good shape. There is a small lip on the very edge of the disc. I can get some decent aftermarket rotors for about $550. The stock ones are almost $1000. They are one piece rotors.

HOLY CRAP! I got custom two piece rotors with aluminum hats and Wilwood HD directionally vaned rotors made to my specs for that price. Replacements are now only $250 a pair since I never have to buy the hats again. There is NO good reason I can think of to buy OE rotors at that price.

Those prices are for all four rotors.

That makes more sense. Hard to imagine that your rear rotors would be worn to the service limit unless in the same amount of time as the fronts. That is not how most cars work.

Stephen Westerfield · **Posted:** Wed Mar 08, 2006 5:07 pm

Rich Anderson wrote:

Hard to imagine that your rear rotors would be worn to the service limit unless in the same amount of time as the fronts. That is not how most cars work.

I replaced the rear brakes on our Passat we use to have almost 15k miles earlier than I had to on the fronts. Weird.

Rich Anderson · **Posted:** Wed Mar 08, 2006 5:13 pm

Stephen Westerfield wrote:

I replaced the rear brakes on our Passat we use to have almost 15k miles earlier than I had to on the fronts. Weird.

VWs have chronic rear brake issues. I think it was the only FMSI D# for a rear that was even close to its front "mate" when I used to keep track of such things. Those cars I why I said "most" cars.

Keith Quistorff · **Posted:** Wed Mar 08, 2006 5:16 pm

Marcus,

Not sure if you know this - it definitely surprised me to find out - if your STi is still under the original 3 year/36kmi warranty, the dealer will replace worn brake pads for free. Same with wiper blades and clutch linings, assuming the wear isn't deemed to be the result of racing (we won't tell).

Check it out at:

http://www.iwsti.com/forums/showthread.php?t=30246&highlight=warranty+pads

THSCC Forums

Rotor Question?

Who is online