BradB

I just replaced my front rotors yesterday with new OEM. The old ones were very worn and cracked. I am prepping for a track day and installed my 1/2 used-up Pagid Yellow RS 29 pads. I took the car for a 1.5 mile test run with ten or so 45 mph to 10 mph braking hits. Not enough for a proper bedding in, but it gave me a wear indication for the pads and rotors.

As you can see from the pic the "inside" of the pads are barely rubbing on the rotors. Do you think the pad material will quickly wear away to create an even wear pattern? Or do they have to be replaced? I hate to give up on these pads because they are only half worn and are so expensive. But I can't live with half the braking force because of a oddly worn pad. And I certainly don't want to ruin the new rotors.

Track rats, what would you do?

Dewinator

I think it's by design, my old rotors had little ridges there and my new ones (oem pads) look like that too.

STG

Old pads take shape of old worn rotors. New pads are best with new rotors. Pads are cheap.

Dewinator

Oh nevermind I didn't see the pic I thought you were talking about the thin unworn ring on the inside.

BradB

Thanks. But I only wish pads were cheap. Pagid pads cost the same as a new set of rotors!

I wonder how quickly things will "even out" ?

Quadcammer

hows the car feel under braking. I'd try to do some more street driving before the event, and if it improves, I'd not worry about it. If it feels crappy under braking I'd probably look to another option.

worst case, sand down the old pads on a bench till they're flat.

BradB

It feels great at 40mph. Not sure it will feel the same way at 140.

But I think I will do some more street driving and if it doesn't "flatten out" I will do as you suggest with the pads...take off $20 or $30 worth of material (!) and see if that gives a better wear pattern on the rotors.

Dewinator

Didn't you say those pads where about 1/2 used? I'm not that smart on brakes but when I replaced mine a couple weekends ago, the pad thickness on the new ones was about twice that on the old ones, which were down to the point where the pad was about the same thickness as the backing. I thought I read somewhere that you don't want it any thinner than that for track use?

BradB

What you read is true. You don't want anything thinner than the backing plate, in fact, it's risky to go that far. The heat transfer to the brake fluid is greater, too.

My Pagids are at least twice the thickness of the backing plate right now. Used, but not dead yet. My problem is getting them to mate squarely with the rotors.

991carreradriver

Not that you asked, but to properly bed Pagid pads, it takes a minimum of three brake motions from 90mph to 20mph. If not, they won't bed properly until you hit the track. Also, I would advise a bit more braking distance until the above has been accomplished and they are track hot. You will feel it when its bedded.

BradB

Thanks! Yes, as I said upfront I know what I did wasn't a proper bedding. I was just trying to see if used pads could be used on new rotors. I'm going to try some more aggressive bedding in, though 90-20 may not be realistic in my 'hood! I hope to see if the pads wear down any flatter.

008

You could take a micrometer to the sides and middle of the pads so you have three measurements across. If you don't want to take everything apart again and have the old rotors you can measure them. If it's excess it's easy to trim or shave pad material. Likely you'll be fine though with a little street driving. I typically rotate pads or swap between calipers so they're not matched pairs anymore when changing rotors.

BradB

That's a great idea. I didn't think of actually measuring the pads. May do that just for grins. I have time to put a few around town miles on the car first and if that doesn't do it I think the plan will be to take off the pads, measure and sand on a flat metal surface.

Interesting tip about mixing up the track pads. I thought you were always supposed to leave them matched.(?) Do you randomly swap all four pads? Or just side to side? I like the idea.

LexVan

Brad, make a run to Augusta and Defiance, buy a case of wine at Chandler Hill, I suggest the Norton, and drive home. Pads and rotors should bed in.

BradB

That's the BEST advice I've had today! And they do a good burger, too!