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Squealing sound when braking?

GT Pony

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Got mine fixed today. The new rotors are definitely a smaller diameter than the originals.
How much smaller? ... I don't want smaller brakes on a GT. I've go low miles, so I'm keeping my fingers crossed mine doesn't develop the squeak.
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GT Pony

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The new ones look to be the same diameter as what is on the rear wheels.
I hope not! Front brake rotors are supposed to always bigger than the rear. That's where most of the stopping power is supposed to be.

I'm wondering if Ford is just throwing something on to appease the issue.

The same rotors are on the GT Performance Package ... so why don't they squeak? Like I've mentioned a few times, what is it about the rotor that makes the brakes squeak? If it was caused by the rotors themselves then the PP would squeak too. Ford should have just found the right pads (ceramic material maybe?) to work with those rotors. If they work on the PP they should work no the non-PP with the right pad compound.
 

HIWATT

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My mistake. I just broke out the tape measure. The new front rotors are 13 inches across. The rears are 12 inches.
 

Varekai

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Anyone able to measure their front rotors before the TSB so we know if they are smaller or if it's just a placebo type thing?
 

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Todd15Fastback

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I hope not! Front brake rotors are supposed to always bigger than the rear. That's where most of the stopping power is supposed to be.

I'm wondering if Ford is just throwing something on to appease the issue.

The same rotors are on the GT Performance Package ... so why don't they squeak? Like I've mentioned a few times, what is it about the rotor that makes the brakes squeak? If it was caused by the rotors themselves then the PP would squeak too. Ford should have just found the right pads (ceramic material maybe?) to work with those rotors. If they work on the PP they should work no the non-PP with the right pad compound.
The regular GT rotors and PP rotors are not the same size. Is that what you are saying above? 6 piston Brembo's and 15" rotors vs. 4 piston calipers and smaller rotors.
 

GT Pony

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The regular GT rotors and PP rotors are not the same size. Is that what you are saying above? 6 piston Brembo's and 15" rotors vs. 4 piston calipers and smaller rotors.
I was under the impression that the Brembo brakes were just the 6-piston calipers running on the same brake rotors. The PP uses the 19" wheels, and I have the optional 19s" on my GT Premium.

I just measured the front rotor radius at 6.5" ... so 13" dia. If the PP uses 15" dia rotors, the back of the calipers must be real close to the inside barrel of the wheel.
 

GT Pony

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Anyone able to measure their front rotors before the TSB so we know if they are smaller or if it's just a placebo type thing?
I just measured the front rotors on my non-PP GT Premium ... looks like 6.5" radius = 13" dia.
 

Todd15Fastback

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I was under the impression that the Brembo brakes were just the 6-piston calipers running on the same brake rotors. The PP uses the 19" wheels, and I have the optional 19s" on my GT.

I just measured the front rotor radius at 6.5" ... so 13" dia. If the PP uses 15" dia rotors, the back of the calipers must be real close to the inside barrel of the wheel.
Correct. The PP rotors are 15". Big difference in size. You can visually see the difference pretty easily.

Here is a pic I found of my front wheel. This should help show the setup of the PP.
image.webp
 

mvp90805

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i think i heard some sqeak on the new ones this morning...i might have to do more testing
 

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GT Pony

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Yep, 1" radius larger is a big difference. The 4-piston caliper on the non-PP is huge, as I think Ford tried to make the pistons in the caliper as large as possible. The back edge (closest to the wheel's barrel) of the stock Ford calipers are just as close to the barrel on my 19" wheels as the back of the Brembo calipers in your photo.

Anyway, I'd like to hear the explanation from Ford engineering why the rotors are causing the squealing. Was there a batch with some bad metallurgy and something happens to them with some miles put on them? Of all the years I've been involved with cars/truck/motorcycles, I've never head of the actual metal rotors causing some crazy decrepit garbage truck brake squealing.
 

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If you're currently experiencing this issue, please PM your name, VIN, mileage, dealer, and best daytime phone number, and I'll gladly see how I can help.
Thanks! PM sent.
 

FordService

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So I finally called in again about my squeal coming back and spoke with Craig from Tuttle-click Ford Irvine. After confirming the TSB, he found the parts are back-ordered as mentioned until April 27th, so i'm gonna have to wait, but at least the issue should be resolved..

Should have called right away :) but i'm a procrastinator.
Glad to read this is being taken care of for you, Celestias; I'm happy to look into this and see how I can help. Please PM your name, VIN, mileage, and best daytime phone number.

Got mine fixed today. The new rotors are definitely a smaller diameter than the originals.

Good news is the trash truck squeal is gone. I also had a squeak in my driver's side Recaro. The dealership was able to fix that too.

If you are in So Cal you may want to contact Theodore Robins Ford in Costa Mesa. They did a nice job for me.
Glad to read this was taken care of for you, HIWATT! :) Please don't hesitate to reach out should you ever need anything in the future.

Thanks! PM sent.
My pleasure, Alloye! :)

Nick
 

POOPonYOU

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Correct. The PP rotors are 15". Big difference in size. You can visually see the difference pretty easily.

Here is a pic I found of my front wheel. This should help show the setup of the PP.
It looks like the new rotors are a smaller version of the PP rotors.
 

POOPonYOU

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My mistake. I just broke out the tape measure. The new front rotors are 13 inches across. The rears are 12 inches.
Glad that someone was able to measure the new ones and confirm that they're the same size as the old ones.
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