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Brake rotor upgrade question

519
16
2012-Boss said:
The front rotor is Motorcraft part BRRF6. Its $81.23 with free shipping from Amazon. See:

http://www.amazon.com/Motorcraft-BRRF6-Disc-Brake-Rotor/dp/B002M48CVQ/ref=lh_ni_t?ie=UTF8&psc=1&smid=ATVPDKIKX0DER

The rear rotor is Motorcraft part BRRF-45. It is $43.66 with free shipping from Amazon. See:

http://www.amazon.com/Motorcraft-BRRF-45-Brake-Rotor/dp/B006DYZ7HI/ref=pd_sim_sbs_auto_1

I like to support our board vendors, but sometimes you find prices to hard to pass up. The fronts are about $30 cheaper not counting shipping costs than anyone else. You can verify the part numbers on Rock Auto if you like. Amazon also has a no questions asked return policy.

Steve

I clicked the link for the fronts and it took me to Amazon. The price is now $135.18 each and they come from an outfit called Titan Direct. The Amazon "Does it fit?" checker says they do not fit a 2013 Boss 302. Hmmm.

The rears are still cheap, come from Amazon directly, and the checker says they fit.

Can someone confirm for me that BRRF6 is the correct front rotor? Thanks.
 
coboss said:
I clicked the link for the fronts and it took me to Amazon. The price is now $135.18 each and they come from an outfit called Titan Direct. The Amazon "Does it fit?" checker says they do not fit a 2013 Boss 302. Hmmm.

The rears are still cheap, come from Amazon directly, and the checker says they fit.

Can someone confirm for me that BRRF6 is the correct front rotor? Thanks.
I'd double check that but it shows it fits a 2009 GT500 which uses the same front rotor as our cars.
 

yknot

Hobbies: Hot Rods & Shooting
I suppose one persons problems may or may not be another's problems. I mean just because one had a problem with a part, manufacturer, or any other defining category, does not mean your going to have the same experience. Most on this subject have subjected the brake system's to extreme wear conditions. Some have hit curbs at speed, run off the track and into holes, slammed pot holes on the interstate and everything in between. Sorry, just because you had a problem, or because I had one, does not mean the product was at fault or that you will experience the same thing. I know this might be new to some, but I have been around way to long to except your fate/problems as my own. You>? that your call.

I do know, if you do not know when you need new rotors, or why...they you probably are not the best at mechanical things. Break pads are just that, pads that are pressed against the rotors at high pressure, to transfer rotational energy into heat energy. That simply means you press on the brake peddle and the pads grip the rotors tightly, making lots of heat, decelerating the rotor speed, slowing the car. These are made to wear....by how much depends on the type pad you select. More aggressive (track) pads will stop faster, but wear much faster also. Street pads, more in line with a factory pad, will stop the car, but with more peddle pressure required, and not take the high temps that follow with repeated quick stop, for long before they glaze over. Generally when the pads wears to the point it needs replacement, factory cars will start to squeal. The makers, install a wear tab, that will hit the rotor, when the pad has worn to about 80%. This is to warn/remind you to seek professional assistance. So to brake faster, or to replace a worn set of pads, you would replace the ones you currently are using.
When a rotor is worn/bad, they do not contain a warning tab that squeaks like th pads. generally when you need to replace a rotor, it will be from extreme use/heat build-up that has warped the rotors. This is felt on the brake peddle, as you press to slow the car, you will often feel the peddle move up and down or bounce. This is the physical reaction of the hydraulic system, to the wave in the rotor. The pads in following the rotor, will move in and out with the wave in the rotors, where normally the rotor is very smooth/true in it's dimensions and the pads glides against it when pressed in one direction only. The other reason for replacement would be the rotor has served its useful lifespan, and through normal/UN-normal, prolonged use, it has degraded to the point that the surface is pitted, rough, cracked, chipped or grooved. Many times a rotor can be saved, by mechanically trimming the exterior surface slightly, to reveal a new, smooth surface to use. Problem is, every time the rotor is cut/trimmed, it loses mass, which allows it to heat up faster, dissipate the heat slower and in general, wear faster then a new rotor would. So do not expect a trimmed/cut rotor to give the same service life a new rotor would. generally you can expect about half the new service life from a cut rotor. meaning, if you got say 50K miles from the new rotors, expect about 25K from the cut ones.
Generally a track car would not consider cut/trimmed rotors, the savings gained would not add up to the loss in track performance. Plus, track conditions work rotors extremely hard. The added heat cycles, stress of competition and braking pad material used, means rotor subjected to track like conditions are used up quickly and tossed. These rotors are far more likely to contain heat and stress cracking, fatigue then a street rotor. The likely hood of a failure, coupled with the high speed and risk of injury, would curtail the re-use of such suspension parts.
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
438
Southeast
Keavdog said:
I'm pretty clear on when to replace pads. How do you know when to replace rotors?

I would check first for surface wear, and runout. Then would resurface the rotor(s), I do like the on car brake lathe system. Depending on the cut needed, you would check the new thickness measurement to ensure the rotors are within specs. Minimum thickness specs are cast or laser etched on the inside of all rotors.

Once you were out of spec, runout, (warped), or minimum thickness, you would replace the rotor. At least that is the way I would decided when to replace a set of rotors. Note: always replace the set, not just one.

When it comes to hard core racing, when the front rotors are glowing red from extreme high temps, I would replace rotors after each race due to temper issues and possible fatigue failures. Drilled rotors should always be inspected inside and out for stress and/or heat cracks. If cracking is evident, replace rotors.

I'm sure there are other ways or thoughts on this matter, but I thing these are some good rotor basics to keep in mind.

302 Hi Pro
 
302 Hi Pro said:
I would check first for surface wear, and runout. Then would resurface the rotor(s), I do like the on car brake lathe system. Depending on the cut needed, you would check the new thickness measurement to ensure the rotors are within specs. Minimum thickness specs are cast or laser etched on the inside of all rotors.

Once you were out of spec, runout, (warped), or minimum thickness, you would replace the rotor. At least that is the way I would decided when to replace a set of rotors. Note: always replace the set, not just one.

When it comes to hard core racing, when the front rotors are glowing red from extreme high temps, I would replace rotors after each race due to temper issues and possible fatigue failures. Drilled rotors should always be inspected inside and out for stress and/or heat cracks. If cracking is evident, replace rotors.

I'm sure there are other ways or thoughts on this matter, but I thing these are some good rotor basics to keep in mind.

302 Hi Pro

Is vibration or shudder through the brake pedal caused by warped rotors, or something else? According to legendary racing engineer Carroll Smith, its the latter...specifically, uneven deposits of pad friction material on the rotor surface, not the rotor itself.

Smith wrote an informative article on the subject, which is posted on the Stoptech site here....http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths
 

302 Hi Pro

Boss 302 - Racing Legend to Modern Muscle Car
2,009
438
Southeast
It could be in a race application, as there are lots of different pad compounds that display different wear characteristics. I would think it would have to be a significant amount of pad material build on the rotor to throw it out of round.

Either way, that brake pedal pulsation is not good and to correct it, I would start with a front rotor inspection, and a dial indicator gauge.

302 Hi Pro
 
I replace mine when a crack reaches the outer edge. Heat checking (small cracks) is normal for tracked cars particularly using race pads. Usually shudder is pad deposits but I've warped rotors just like my 80s hair band vinyl records so don't always assume it's pad deposits. I always bring spare rotors to the track but it's best if they're used (seasoned). If you have to swap brand new rotors put used pads in and run the first few laps like you're under caution then maybe one at 8/10 and then a cool down lap and come in to let fully cool before next session.
 

steveespo

Lord knows I'm a Voodoo Child
Moderator
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Cookeville TN
Good advise Gary. I heat check my OEM 15" rotors after a day, but have yet to crack one at all yet. DBA drilled and Girodisc Cryo treated 14" parts I would get radial cracks after the 1st 2 or 3 days. They're toast when they get within an 1/8" of the edge.
Steve
 

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