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Discussion Starter #1 (Edited)
Disc brakes and my experience.

See pic, this is from ’02 Lin Cont, 40K miles and perfect maint from the selling dealer. No brake work done, just checked out each maint period. I bought the car from a dealer who took it in trade. Drove it and told the salesman with me the brakes had a problem. I would describe it as a ‘hop’ not exactly a pulse, and not in the pedal or steering wheel. They offered to fix it or give me a credit. I was 375 miles from home and no way I was going to leave it there and stay overnight or make a second trip. I do not remember the credit as it was rolled in with the trade-in and transit tags and such.

When home I did the old parking brake at 30 or mph and the rear had a "hop" so I knew it was rears. I got new rotors and ceramic pads and replaced the rears and it is just fine.

The rear pads measured 11.5 mm pad thickness to the new pad 12.76mm or about 90% of new thickness, that is, if the factory pad was the same new as the replacement. The pad is FF or aggressive cold and aggressive hot by definition. It is metallic and very magnetic.

Now the real issue. In the picture of one of the rotors, I measured the thickness around the disc, in the same distance in, all around to the 4th dec. place. Also got the original thickness from the rim by sanding the rust off one location and mikeing that point.

Normal spec for thickness variation is 0.0004" and this one is 0.0042 or over 10X the allowed out of thickness and nominal 0.010 reduction in metal thickness by wear done by the hard metallic pad. The uneven wear of thickness is normal. It is the principle that makes a gravel road get the washboard rumble.

The fronts have non-magnetic pad material, and is likely ceramic or organic, and EE or normal brake friction range, cold and hot. The pads look to be good for another 40K and there is no measurable change in rotor thickness. They work line new.

One more point here. Using FF (grabby) pads on one axle and EE (normal) on the other makes the FF do much more work than the other axle. In this case, the rears are overworked. By logic, a bad balance. By the book factory spec is ceramic front organic rear. Both would be EE pads. Another Ford "put whatever is handy on the car".

By the book spec for rotors
Thickness variation 0.0004
Runout 0.0024
The allowed runout is 6X the allowed thickness variation.
THICKNESS is the critical part.

Opinion:
I think much that passes for "warp" is actually thickness variation brought on by rotor wear. And that from metallic pads.
Off my soap box, over and out from the old coot.

-chart-
 

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Interestingly, in your picture I can see brake pad outlines and those areas are slightly thicker due to the accumulated glaze. That's not enough to explain your variation, so I wonder if there was just a defect with the rotor or a result of an overtightened lug nut or something.

Excuse my ignorance, but is the friction rating of FF stamped or printed onto the pad somewhere? Do I see FF on your new pad? Does the factory manual specify friction coefficient ratings or just the materials? FF seems to be the standard nowadays, so the fronts might be FF too?

I have noticed a trend toward increased rear brake force on the newer Fords. Some Fusion owners are seeing completely worn out rear pads at only 15,000 miles and the fronts are like new.
 

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Discussion Starter #3 (Edited)
Interestingly, in your picture I can see brake pad outlines and those areas are slightly thicker due to the accumulated glaze. That's not enough to explain your variation, so I wonder if there was just a defect with the rotor or a result of an overtightened lug nut or something.

Excuse my ignorance, but is the friction rating of FF stamped or printed onto the pad somewhere? Do I see FF on your new pad? Does the factory manual specify friction coefficient ratings or just the materials? FF seems to be the standard nowadays, so the fronts might be FF too?

I have noticed a trend toward increased rear brake force on the newer Fords. Some Fusion owners are seeing completely worn out rear pads at only 15,000 miles and the fronts are like new.
I took a pic of the pad off this car, removed the spring so as not to confuse the camera in closeup. Also shows what the friction code printing looks like. This one held up by a magnet as the pad is made of steel.

The replacement rotors and pads now have ~5K miles and I looked today and the crosshatch grind marks are still quite visible, so they still look like new.

As to Ford and their brake issues.
Our son bought a new Freestyle and they recalled them for rear brakes. Maybe a year old and his rear rotors looked HORRIBLE. Dealer put new rotors and pads on and it now is over 100K with those pads and still doing fine. When I was looking for my Lin Cont online, I copied the first 14 cars with free carfax, and also started life as a personal owner. (fleet cars and Ford owned cars rarely show any maint under the period of ownership)

7 of the 14 Lins had brakes replaced at maintenance warrenty stops, and 2 of that 7 were before 300 miles. None repeated and none after warrenty were reported. They usually showed new pads and re-surfaced rotors.

The car I bought should have been culled out during it's scheduled maint, but they checked and did not find anything. I use the word "checked" loosely.:lol2:

Somehow, the idea of using steel pads against cast iron rotors just rubs me the wrong way. (pun intended)

Steel pads are for police, taxi, and racing.

-chart-
 
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