GT Nate

So I put on new drilled & slotted rotors with semi metallic pads. I just swapped the pads for ceramics as they're SO MUCH MORE quieter.

However, it seems my pads extend past the rotors. I got them from Primechoice.com and they seem to fit, but the front's sure seem too small. Look at the pic. Are all GT's like this? where the pads extend past the rotor. This means as they wear they'll make a rounded groove where the upper part of the pad won't ever contact the rotor. WTF?



Am I missing something? The rotors bolted in exactly as it should be. Just wondering if they sent too small front rotors.

Thanks,
N

08'MustangDude

That does not mean the rotor is too small, not if you have dished wear. If your pads
were dish worn, then they would be too small. You'd have an unworn edge in the pads, not
the rotors. That is not what you're showing. Your pictures indicate your rotors are a
few millimeters too big, or the pads are a few mm to short.

That is not wearing past the rotor, the pads just don't go all the way to the edge
of the rotor. That's almost normal, and that is called dished wear. It all depends
on where you got the pads or aftermarket rotors. China made rotors are notorious
for being a few millimeters too big.

I just changed my '15 TSI rotors and pads, from stock, to slotted and drilled with
ceramic pads. The stock rotor was dished worn, the pad didn't quite reach the end of
the rotor, and that was from the factory. The pads I have on now, with the aftermarket kit,
are almost dead on.

When you buy replacement rotors, they can be off by 1 or 2mm, always longer,
never shorter. IF the pads wore past the rotors, you would have dished wear
IN the pads, not the rotor. So, your pads are either a tad smaller than the ones
you had, or the aftermarket rotor is a few mm to big, and that is fine. You do not
want the pads with the dished wear, and personally, I have never seen that, just
dished rotor wear.

See:

That came off my '15 TSI, and there is a slight lip on the edge of this rotor, the other side was the same.

My slotted and drilled are brand new, last week, so I won't see how that wears till much later.

You can find all kinds of pictures and tutorials with brake pad and rotor changes, and you will see
most of the rotors come off worn like that.

GT Nate

I'm referring to the OUTER edge of the rotors, the pads extend past that. They're not supposed to.

OEM rotors are ~12.5" these are closer to 11.5" If they were bigger there would be a very thin line where the pads don't quite reach the outer edge of the rotor.

What I'm trying to show is that the pads near the outer edge are not in contact with the rotor at all. There's no dishing or anything like that. This means as I keep driving I'm going to wear the inner part of the pads out while the outer edges will stay thick.

I'm calling the vendor tomorrow to see if they sent me the wrong size. Not sure but maybe V6 Mustang rotors are slightly smaller.

Car stops fine, but I don't want f'ed up brake pad wear.

Thanks for you input though amigo

JimC

Rear rotors are the same size. Only the front rotors are different size between the V6 and V8.

And for the fronts the size difference you mention sounds about right.

08'MustangDude

Sorry man, that rotor looks dished to me. I can't see anything behind the rim.
It's too dark, and I can't see anything but a rust strip towards the hub where it looks
like NO pad is contacting it, and a lip around the edge. That's what I see in the
picture because I can't see anything where the caliper is, too dark.

And yes, V8 rotors are larger than the V6.

Should have taken the picture with the rim off, flash active, and we could see it better.
I just thought maybe you meant the other way around from what I see. SO, you got
about 1/2" of pad not on the rotor...

Dino Dino Bambino

You've been sent the wrong rotors, pure and simple. Could be the rear rotors the vendors sent you instead of the fronts.

howarmat

i would agree that something is a not the correct part. Most likely the rotors

GT Nate

Actually they're right parts, they list them as front and rear and do call out the GT for them.
TO save time and hassle I just ordered the correct 12.7" ones with slots and holes (same pattern), they'll be in soon and it'll be a 20 minute swap.

Mistake on my part...they didn't list the SIZE of the fronts. The fronts in this kit are thicker, just not larger in diameter...can't believe I didn't catch that.

Oh well, buying new ones is peace of mind.... live and learn amigos!

GT Nate

The new PROPER sized front rotors are on, Much better braking.

Who would sell front rotors for a GT that are the same size as the rears?

Norm Peterson

Being sent thinner rotors was as serious a fault than being sent rotors of too-small diameter, maybe even more so. A rotor that's too thin has the potential for allowing the caliper pistons to be pushed out too far - and those first set were probably well below the thickness to discard.


Those diameter and thickness errors taken together would shorten the time until the caliper pistons would be trying to fall out of their bores leaving you with zero front braking and a brake fluid mess to clean up.




Norm