warped brake rotors

[jasonstang]

I wonder why they don't make the old rotor wearing pads anymore. It seems like all new pads are designed to deposit a layer of material on the rotor but never scrub it off.
The pads I have on my RX-8 R3 would scrub the rotors during normal driving so any deposit would come off and you can see the rotor gets thinner and thinner.

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[HISSMAN]

They should make asbestos pads again...

 

[Optimum Performance]

Do Not Turn Shelby Rotors

SSM 45903 - 2015-2017 Shelby GT350 And GT350R Brake Service
2015-2017 Shelby GT350 and GT350R vehicles should not have the brake rotors machined when servicing the brake system. Replacement of brake rotors is the only acceptable service of brake rotors on GT350 and GT350R vehicles. GT350 and GT350Rvehicles are equipped with a brake system designed for high speed and superior fade resistance. Occasional brake squeal and elevated levels of brake dust may occur. This is normal and does not affect brake system performance. Refer to the Workshop Manual Section 206-00 and the Mustang Owner's Manual and the Shelby GT350 Owner's Manual Supplement for further information.

APPLICABLE VEHICLES
2015 - 2017 CAR: ZG MUSTANG (S550)

Additionally Ford has extremely tight tolerances and procedures for on the car rotor turning and run-out (spec is basically ZERO) I have had customers turn regular Mustang rotor is the surface finish was horrible so no suprise they make noise. Ford actually has training videos on using the on car lathes because so many people complain about brake noise.

To the OP we recommend an R8 Pad Front and Rear for Daily and limited track use. You can step up to an R12 up front if you are running a heavier braking track and just swap the R8's back on for DD.

 

[snaproll]

I wonder why they don't make the old rotor wearing pads anymore. It seems like all new pads are designed to deposit a layer of material on the rotor but never scrub it off.
The pads I have on my RX-8 R3 would scrub the rotors during normal driving so any deposit would come off and you can see the rotor gets thinner and thinner.

Man I remember a few rotor wearing pads! An aggressive pad like the old Hawk blues can absolutely machine a rotor to destruction when cold - like on the street. You'll have Dust, rust, and a mess with some pads used on the street.

I would plan to stick to OEM and if one is searching for more of something, try a PFC, Hawk, Raybestos, Pagid, etc race compound on track. There's no free lunch. What works on track best is obviously not going to go 70,000 miles on the street. And what's unfortunate about the otherwise perfect GT350 brakes is the typical thin street pad. Oh well. What I wouldn't pay for an extra 1/2"

My guess is a Hawk DTC 70 and a Raybestos pad of some compound will prove to be a couple of reliable and economical choices for the track as those are the favorites of the Spec Iron crowd for proof of performance.

And Ford can say what they want about turning. I wouldn't do it and there should not be a reason to do it, but if you want to try, it's just a matter of having enough thickness. This isn't rocket science. And taking a couple mm's off these rotors isn't going to make them explode. In my experience you take a new pad and put it right on to your old grooved rotor and just step on the brakes. Works fine.

 

[RoadRacer]

Not to go too sideways with this topic but is anyone beside me concerned with repeated removal & re-torqueing of the front caliper bolts? I don't have a good feeling about the aluminum threads lasting very long. I'd like to install studs in the knuckle and use high quality flange nuts. Opinions and other possible solutions (helicoils?) welcome.

 

[GT_Dave]

Not to go too sideways with this topic but is anyone beside me concerned with repeated removal & re-torqueing of the front caliper bolts? I don't have a good feeling about the aluminum threads lasting very long. I'd like to install studs in the knuckle and use high quality flange nuts. Opinions and other possible solutions (helicoils?) welcome.

There are only 2 things that will deteriorate the threads in aluminum, over-torquing the bolts and abrasion or galling. Lube the caliper bolts with anti-seize, making sure all threads are clean, and use your torque wrench.

 

[RoadRacer]

There are only 2 things that will deteriorate the threads in aluminum, over-torquing the bolts and abrasion or galling. Lube the caliper bolts with anti-seize, making sure all threads are clean, and use your torque wrench.

How about repeated use of thread locker? Have you removed your front calipers yet? Mine seem to have a significant amount of running torque. I always use my torque wrench.

 

[Optimum Performance]

Not to go too sideways with this topic but is anyone beside me concerned with repeated removal & re-torqueing of the front caliper bolts? I don't have a good feeling about the aluminum threads lasting very long. I'd like to install studs in the knuckle and use high quality flange nuts. Opinions and other possible solutions (helicoils?) welcome.

Full strength inserts like THIS

You just need to find one that has the correct depth. They will not fail under most conditions. The Heli-Coils just do not last in Aluminum and usually unwind. It would take a fairly large run to produce studs and you would loose the ability to support the caliper during brake maint. You could design a stud with an internal threaded end that would allow an extension to be screwed on the end of the stud.

And I will add the stud needs something to bottom on, so it either needs a shoulder or needs to bottom out in the hole otherwise the stud has nothing to hold it in. In steel it's easy with just a shank but aluminum is more of a challenge. Not seeing one in person it appears the caliper mates flat to the spindle. The stud would be fairly easy to produce but just not sure how it would hold during repeated cycles just installed bottomed out with a thread locker.

The area for a nut is very small, you would likely need to make a capped nut with an internal drive (Torx or Allen) which would add cost and complexity to it. The spindles are only about $200 so would it be worth the expense to develop all new hardware?

 

[RoadRacer]

^^^^ Thank you for the well-thought assessment of the caliper attachment options. Your last point about the replacement cost makes me less worried about this down the road. I'll continue to take care when servicing the brakes per GT Dave's comments and replace the knuckle if/when I ever have trouble. Thanks!

 

[Optimum Performance]

We include thread locker with the pads we sell but honestly I would personally use anti-sieze on a track car where I am in there very often changing pads. We just can't really go there because we can not control the public doing something stupid, like not inspecting threads and using a torque wrench. 136ft/lbs is pretty stout torque. As long as you keep dirt and old thread lock out of the threads I doubt you would ever have an issue with either method. At the track you could just use a piece of vinyl tubing to blow out the holes if you don't have compressed air. Make sure the bolts are clean going back in. Standard "Mechanic Practices" you could say

 

[RoadRacer]

^^^^^Great advice...thanks again.

 

[50 Deep]

During my third hpde my car started develop a pretty good shudder under braking. Now on the street when the brakes warm up it has a noticable shake.
Anybody else experience this?
I'm aware the rotors should not be turned.

The car I drove at the track attack was like this. Still hauled to a stop no problem

 

[FordService]

During my third hpde my car started develop a pretty good shudder under braking. Now on the street when the brakes warm up it has a noticable shake.
Anybody else experience this?
I'm aware the rotors should not be turned.

Have you been able to address this with your Ford Dealer, Screamer? If not, I recommend you bring it in and get it checked out. Be sure to PM me with your VIN, dealer, mileage, full name, and best daytime number. I’ll loop in the customer service manager for your area if needed.

Deysha

 

[Screamer]

Have you been able to address this with your Ford Dealer, Screamer? If not, I recommend you bring it in and get it checked out. Be sure to PM me with your VIN, dealer, mileage, full name, and best daytime number. I’ll loop in the customer service manager for your area if needed.

Deysha

Thanks Deysha for your interest. Car was at local dealer today. New rotors have been ordered

 

[Screamer]

All fixed! Velde Ford replaced both front rotors today.

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