REVscene - Vancouver Automotive Forum

Jet · 07-04-2010, 10:50 PM

Hey,

I got a question about rotors, I bought slotted and dimpled rotors and installed them on my car with new pads and all that ... its time for me to change to a new set of pads since I'm pretty much done with them, my question is about the rotors, can I get them machined and then use another set of pads or do I need to replace the rotors as well, I heard somewhere that rotors can typically go through 2 sets of pads before replacing but at the same time I've heard some say that I can't machine the rotors cause they might crack or something cause they are slotted and dimpled ... Ideally I'd like to just get them machined and then slap on some pads and then think about replacing them next time ... thanks for the info ...

G-spec · 07-05-2010, 10:01 AM

good rotors should last you lot longer than just 2 sets of pads. But in between pad changes make sure the rotor surface is even, especially with drilled/dimpled/slotted rotors because they tend to warp easier than normal OEM style rotors. Personally the only drilled rotors I would ever buy would be high end brake setups like Endless and Brembo, etc.... a lot of the cheaper kits their drilled rotors end up warping, slotted is about as far as I would go when it comes to rotors since I only street drive my car.

And yes if they are uneven, go get them resurfaced before putting the new brakepads on, otherwise you will experience a lot of brake shudder and the car will feel like it's wobbling under braking. I've had my OEM rotors warp and it was exactly as I described it, I got them resurfaced at a local shop and they've worked perfectly fine since.
I actually just swapped my whole brake setup myself, complete with new rotors and new ceramic brakepads, I went with OEM style rotors.

SumAznGuy · 07-05-2010, 10:06 AM

Get the rotors checked out to see if there is any cracking or if they are above minimum recommended thickness.

If they are too thin or cracked, then you will need new rotors. If not, then find a machine shop with the proper equipment to resurface slotted/drilled rotors. Not all machine shops have the equipment to do it as slotted/drilled rotors are not as common as OEM style blanks.

Jet · 07-19-2010, 08:53 AM

Thanks for the info guys ... does anyone here know of a local shop that you go to that can check/resurface my dimpled/slotted rotors ... I know there are a number of guys here that are mechanics and have shops but I do not know any of them ...

Phil@rise · 07-19-2010, 11:47 AM

Run your fingers over them from the inside out are they noticeably wavy? Most drilled /dimpled rotors get wavy. If so and if its not to extreme they can be machined but at the cost of cheaper aftermarket rotors you may be better off to buy new ones.
If you'd like a quote PM me with more details about your car and the current rotors.

shenmecar · 07-19-2010, 08:40 PM

My take on determining whether rotors need to be machined is to brake at highway speeds. If the steering shakes. Then your rotors are "warped" and need to be machined.

Jet · 07-20-2010, 08:44 AM

I'll take a look at the rotors when I get a chance after work but I've never had problems with shaking when braking on highway speeds, last time I checked that was maybe a month or so ago on the I5 but I'm pretty sure rotors needs to be machined either way to get rid of the old brake pad material or am I wrong

Berzerker · 07-20-2010, 09:09 AM

There was a great article and thread on brake "warp" awhile ago you all should read if you think warping happens that easy and as common as you guys all seem to think

Rotors will need to be replaced depending on the pads you use. Sometimes you go to a brake place and they offer you a "lifetime warranty" on the pads they put on. That's because they are so fucking hard that the rotor will need to be replaced before the pads do meaning more money for the brake shop in the end. If you have soft pads with high grip like Hawk's you could wear through several sets of pads and not have to replace the rotors. Usually as long as there is no uneven wear from inside to outside you can just throw on a new set of pads but if there is any waves or grooves the rotor's should be turned.

Berz out.

Mugen EvOlutioN · 07-20-2010, 09:32 AM

except motherfucking hawks squeaks like a pig being slaughtered.

tried 3 set of hawk hps, and all squeaks after driving agressively.

tried hawk ceramic performance set, grabs shittier and also makes noise

fuck hawk

going project mu next time

Szeto · 07-26-2010, 01:32 PM

+1 on project mu. Wanting to get their bbk...

Mugen EvOlutioN · 07-26-2010, 06:43 PM

^

project mu means serious $$$$

Stealth1 · 07-26-2010, 11:40 PM

Unless you feel pulsing or the steering wheel shakes your rotors are probably fine, just make sure they are above the manufacturers recommended minimum thickness. The only thing I would recommend is lightly scuffing the surfaces of the rotors before putting the new pads on. Then go and follow the pad manufacturers recommended break-in to get the proper pad transfer onto the rotors.

The most common cause for rotors warping is when people brake really hard multiple times and then go and get a car wash. The water hitting the hot rotor will cause them to warp very easily. Slotted rotors are not prone to warping more than a blank rotor. Drilled rotors are a waste of money and are prone to cracking with most affordable brands as the holes are actually drilled which will leave microfractures in the rotor. The only drilled rotors I would ever use would have the holes cast into the.

tofu1413 · 07-27-2010, 06:31 PM

Quote:

Originally Posted by Mugen EvOlutioN

^

project mu means serious $$$$

but worth the money!

Mugen EvOlutioN · 07-27-2010, 08:26 PM

yup

aint gonnna buy stupid axiss / hawk shit no more

Lomac · 07-27-2010, 11:30 PM

Quote:

Originally Posted by Stealth1

The most common cause for rotors warping is when people brake really hard multiple times and then go and get a car wash. The water hitting the hot rotor will cause them to warp very easily.

While it's technically possible for a rotor to warp through such a method, you will never notice it while driving. Calipers are designed to let the piston follow the rotor regardless of if it's straight and true, or warped (imagine a vinyl record that's been in the heat for a short amount of time). The "warped rotor" symptom that people feel are actually material deposits, aka cementite inclusion. This is usually a result of an improper break-in of new pads, or an hot-spotting from run out at higher temperatures.

Overseas Auto1 · 07-28-2010, 03:56 PM

put on EBC

Stealth1 · 08-03-2010, 11:42 PM

Quote:

Originally Posted by Lomac

While it's technically possible for a rotor to warp through such a method, you will never notice it while driving. Calipers are designed to let the piston follow the rotor regardless of if it's straight and true, or warped (imagine a vinyl record that's been in the heat for a short amount of time). The "warped rotor" symptom that people feel are actually material deposits, aka cementite inclusion. This is usually a result of an improper break-in of new pads, or an hot-spotting from run out at higher temperatures.

A warped rotor can definitely be felt under braking.

Also forgot to mention that alot of people install new rotors and think they are warped when in fact the problem is the rotor is not sitting flush on the hub.