Hello,

I ordered a set of apx rotors and a set of ebc yellows. Intalled everything, and then followed the bed in procedures from apx: 3 stops from 30mph, 3 stops from 50mph, and 3 stops from 80mph. Naturally the brakes were smoking when i started 80mph stops. So after all were done i cruised around to let them cool off, but they didnt feel right... So i did 3 more stops from 80mph... Cool off, but they still feel like crap. Vibrating like crazy...

What should i do? Another 3 stops from 80? Maybe one long stop from like 180?

 

I'm not a brake expert, but isn't Yellow EBC for racing? If it is, it's most likely not compatible w. street use. In the several times I've bedded in pads, I've never had smoking from 3-30 mph and 3-50 mph stops (and they weren't stops; they were slow down to a few mph).

This is what I found on EBC site: "Product Features

Replaces Stock Brake Pads
Made for Racing Applications and also Truck & SUV's
EBC's Strongest Gripping Pad
Special Brake-In Coating ensures Proper Bedding
Beveled Edges and a Center Line Slot for Quiet Braking
Center Line Slot also Vents in Cool Air to Prevent Cracking from Heat
Excellent Initial Bite that Improves as they Heat Up
12 Month/10,000 Mile Factory EBC Warranty


Product Description

EBC Yellowstuff Performance Brake Pads are the must have for your track car, and even your truck or SUV. Yellowstuff Brake Pads are the highest rated friction pad of any EBC Brake Pad. Unlike most race brake pads EBC Yellowstuff Pads do not require warm up to perform at its best, making Yellowstuff great for everyday street use as well. If you own a truck or SUV and want a good pad for towing than the EBC high friction Yellowstuff Pads are perfect for that as well.

EBC Yellowstuff Performance Brake Pads are also designed to perform quieter than most other Replacement Rotors. The Beveled edges combined with a unique center line slot help keep your brakes quiet and also aid in preventing thermal cracking due to excessive braking.
Notes

When shopping for both front and rear brake pads it is recommended that the same compounds are used. Each compound has unique stopping characteristics and putting different compounds on the front and rear of your vehicle could compromise the performance of one or both sets of brake pads. Professional installation is recommended for all brake pads to ensure your safety and the safety of others."

 

Did you mean AFX rotors? Make sure the hardware on them is tightened. Also check your hubs and calipers...

good luck!

 

Thanks, i know they racing pads, i drive on the autobahn, so frequent high speed stops.

All hubs are good and so are calipers

 

Pull the rotors and make sure they do not need turned
I know they are new but you may have warped one during break in
Check the pads for excess glazing which could create chatter

 

So doing another brake-in is not going to help?

 

Did you break in the brakes by using them lightly until the surfaces were all clean and smooth BEFORE you bedded them? It sounds like you didn't and just went for the hard stops when they were not smooth and clean. That gave you uneven heating which warped the rotors or at least put an uneven layer of pad material on them which will result in vibration that will only get worse with time. I'm thinking that at this point you need to have the rotors turned to get them level and clean again, BREAK THEM IN SLOWLY until they work well, THEN bed them for maximum performance.

From the owner's manual:

 

I followed afx procedure to the T. There was no information about braking gently first.

Can they be turned? They are slotted...

Im a bit pissed, i paid over $600 for these (i already had hubs, so just replacement rings) and now i have to cut them?? Plus, in germany they dont cut rotors, it is illegal...

So cant do another brake-in?

 

I agree with FtMorgan, I think that material was transferred from the pads to the rotor and this is causing the vibrating. It could be that you warped the rotors but this is much harder to do.

 

That's a good policy...most brake manufacturers do not endorse turning of rotors nowadays. Light sandpaper by hand will remove any transferred pad material, without removing any significant amount of metal.

 

Is the vibration through the pedal that your feeling? That is usually caused by the pads riding over an irregularity on the rotor, such as a warp. Its the pads pushing back into calipers at the moment they ride over irregularity & in turn its felt through the pedal as a pulsing.
If the vibration is at the wheel than could mean a loose component there. I've also heard of some folks needing to balance their rotors much like you do tires. Not something most need though.
I've done a bed not too different from yours & all went fine. Smoked & smelled also. Don't see how an additional bed would help. Bedding is to introduce, you can say, the pads to the rotors by heating them up. Transfers some initial pad material onto rotors. Idea behind the cool down drive & not stopping is so you don't get a hot imprint of pad outlined on rotor when it rests in that one spot too long.

 

If you already know about everything else why are you asking can you bed them again?



good luck.


You can bed them once a day is you like. Will it fix it? Doubtful. Warped is warped and not usually self correcting.

 

Sounds like you glazed the pads when bedding them. That's not good especially if you plan to race the car. Take a look at the pad material, if it is really shinny they are glazed and they need to be sanded down. MY concern is if you glazed them while trying to bed them, how are they going to last on a race track?

 

Check and retorque all the bolts. Look at everything and make sure it is all installed correctly. Put a dial indicator on the rotors and check for runout (very important). If you have more than a few thousandths runout, you have to address this first. Lightly sand the pad faces and the rotors to remove any glazing or pad transfer to the rotors. Check the lug nut torque, etc.
Were you suposed to let the brakes cool between the brake in steps?

 

Thanks, will check.


I read a pretty good article a while back, and it mentioned that there is no such thing as warping, only pad material transfer, and that few heated stops will solve the problem. So, i guess i was just looking for someone to confirm. I went out today and did a few hard stops, and became better. I contacted ebc and they told me to take it easy for few hundred miles and it should fix it.

Thanks all for ur time

 

I wouldn't go along with the idea that there is no such thing as warping, only because I have seen discs turning on a lathe that were having much more material taken off in some places than in other places on the disc. This means that the lathe was trueing the disc and not just providing a smooth surface finish. However, I think the vast majority of brake pulsing/vibrating problems are caused by material transfer and not warping. Also, as I said before, most if not all brake manufacturers recommend against turning discs these days, unlike the way it was common practice in the past.

 

ROTORS CANNOT WARP. They do not turn into potato chips. What you are experiencing is uneven material transfer from the pad to the rotors. Break in should have been an even smooth pedal pressure applied during the braking procedure. Now you have hills and valleys of pad material which continue to grow with every brake stop. The pads are no longer riding on a smooth rotor surface.
The rotors need to be turned, yes the slotted ones can be turned, then washed with soap and water to make them very clean. If you still want to use these pads on the street then the break in procedure must be done as mentioned above.
If you are at the track just a small portion of the time I would consider getting a set of street pads and changing them to a more aggressive pad for track use.

 

You don't drive home on a brake lathe. The place where the rotor lives is much different than the lathe. I can show run out by rotating the rotor 180 on the hub. Is that a warped rotor then? It is not straight.
Our engineers just smile when someone mentions a warped rotor.