Bigmikee

j beede

Did you or the mechanic bed the new brakes using 60-20x10? Maybe you had softer pads on the old car?

Bigmikee

Does 60-20x10 mean taking the car from 60-20 mph 10 times? I tried a couple of harder (not full abs) brakes from 80-20 mpg, drive for a few minutes, then repeat. I did this 4 or 5 times, but definitely not 10 times.

j beede

Yes, slow from 60 to 20 ten times. You need to avoid having the pads rest against a still rotor while it is hot (HOT) during this process. Don't come to a complete stop and don't park until the rotors have cooled. Once I feel pulsing I have never experienced it getting any better or going away. In that case resurface or scuff the rotors, install new pads and re-bed.

Maybe you could send an e-mail to Pagid and ask for suggestions: infoUSA@tmdperformance.com

Petza914

You don't necessarily need new pads, you can remove the current ones and remove any surface glazing on the lads with a rough sandpaper, like 80 grit (wear a respirator or mask), clean the rotor running surface with brake cleaner, put anti-squeal paste or the factory pad dampeners on the rear side of the pads, reassemble and then rebed.

Bigmikee

I will try bedding the brakes this weekend. Thanks for the advice.

Bruce In Philly

2009 C2S 126K miles

OEM does not necessarily mean that those are Porsche rotors or pads. I almost always buy OEM whatever and save big money, but I remember back... oh about 40K miles ago... when I did my rotors and pads, the pads at Pelican denoted as OEM did not have the little round anti-squeal weights on them despite being Textar brand. Textar is an OEM supplier to Porsche but those weren't the pads that Porsche supplied. Again, I have no problem with OEM and do it all the time but you have to be careful if you really do want a Porsche part. If you do, then you have to be careful when you buy OEM.

BTW, in 18 years and about 300K miles of owning two Porsches as my only, all year car, I never had brake squeal. I know on my Boxster, I had my indy use OEM rotors and pads (so he said and I believe him) one time and those rotors definitely were not Porsche rotors as the hats were not painted and they grew a fine coat of rust. They performed perfectly, but they were not real Porsche rotors.

Peace
Bruce in Philly

Bigmikee

j beede

I think bedding involves three processes:

1) Heat curing the adhesive used to fabricate the pads
2) Outgassing the pad material
3) Depositing a thin film of pad material on the rotor

I don't think you can easily accomplish this with used pads and rotors. Roughing the pad surface to de-glaze them may address the squealing. I mentioned before watching Edd China (on TV) use an angle grinder to remove the lip off a used rotor and then a wire brush in a hand drill to scuff the surface. I have never tried that. You asked for ideas!

SpartaEvolution

Beede has the right idea. The pad bed-in procedure is vital for proper brake performance and noise reduction. The proper bed-in procedure gradually increases the brake systems heat to optimal temperature range of the brake pads and assists in depositing a thin layer of the pad material to the rotor. The heat curing to bond the pad backing to the compound itself occurs in the manufacturing process as there are multiple ways to adhere the compound to the pad backing plate from adhesives to physical hardware, dependent on the pad manufacturer.

As far as roughing the rotor surface, using a 100-200 grit sand paper is fine, but do not press into the rotor as that can cause uneven de-glazing and even remove material that you do not want to do. Also we suggest that you DO NOT use an angle grinder to remove the lip of a used rotor as doing this unevenly can cause the rotor to be unbalanced which can lead to brake vibrations. If you have a lip on your rotor, double check your rotors minimal thickness to make sure it's not time to replace the rotors.


As far as in a proper bed-in procedure, this is what we recommend. Do not that as important it is to gradually induce heat into the system without causing thermal shock, its as vital to let the brakes cool down afterwards. It's best to let the vehicle sit for 1-2 hours after the bed in procedure to ensure that the system dissipates heat and avoids hot/glaze spots.

1. While the vehicle is stationary, pump the brake pedal to ensure pad contact. The brake pedal should feel firm and have standard travel.
2. Drive the vehicle cautiously a short distance to test fit and function. The brakes should be smooth, with no vibrations, judder, etc.
3. Drive the vehicle to a remote area and perform at least 20 brake applications of 3-second duration. Use light deceleration with varying starting speeds. Stoplight traffic can work well, too.
4. The purpose of this procedure is to gradually increase the temperature in the components without inducing thermal shock, and to mate the brake pad and disc friction surfaces.
5. After the repeated stops, drive the vehicle for several miles (on highway generally) with little or no braking to adequately cool the components. While on highway, perform 10 braking applications using light to medium pressure for periods of 5 seconds
6. After the above process is completed, the system is ready for normal use.
a. Note: that pads and discs are a set once mated together. Changing to a different pad material after the previous material is bedded into the disc may cause pedal judder, vibration, and squeal issues.
7. Because of the heat buildup in the brake system during extreme use, you need to let the brakes cool down by driving normally for a short distance before stopping. This cool down period not only helps the longevity of the brake system, but also the entire vehicle.

j beede

I did brakes on two cars from our "fleet" this week. A few observations:
I am no longer doing 60-20x10 as I think this produces too much heat. I see that Hawk recommends 35-10x5 then 45-10x5 which I will do on my 997 when I do those brakes next week. One car had squealing from the rear drums. I pulled the wheels and saw clear evidence of glazing. I used 100 grit to scuff the surface of the shoes--maybe ten passes with moderate pressure until the surface looked new and homogeneous. I did not re-bed them as they had already experienced plenty of heat via 60-20x10. Pedal feels great and no more noise. Good.

geeky

That's good to know!

SpartaEvolution

J beede that sounds great and a great remedy for the drum brake

As for the Hawk procedures for pad break-in, we're sure that their procedures are the best solution for their compounds so always refer to the pad manufacturers bed-in procedure. One thing we do suggest specifically for the Hawk procedure is to let the system cool down fully. We know they recommend an approximate ~15 min cooling period but that is not ideal for any brake pad. We suggest a 1-2 hour period of cool down to ensure even cooling of the system.

Petza914

I've streamlined my bedding procedure to take much less time and haven't seen any difference in results - meaning proper brake bite, modulation, and no squeal. What I do is drive to a remote area a few miles away and on the way there, do very light braking, avoiding coming to a complete stop whenever possible. Once I get there, I do a series of stops with light pressure from 30 to 10, then from 40 to 10, then from 50 to 10, then I do a couple with moderate pressure from 50 to 10 and 60 to 10, then a couple more from 60 to 10 at about 8/10th braking capability. After these, I drive back home trying to not use the brakes at all so I get them fully cooled. Once parked, I don't set the parking brake and I use my infrared thermometer to check the temperatures at all 4 wheels looking to see that both fronts are around the same temp and both rears are around the same temp, but they could and usually are different from each other. I use this process independent of what make or type of brake pads or rotors I'm using.

SpartaEvolution

Petza, that's a great process to use for any kind of pad as you are ensuring a consistent thermal load and cooling without shocking the system.

Just to make one input, for the 997 platform, utilizing the parking brake after bedding new brakes is fine. The only time you do not want to set the parking brake is if your parking brake mechanism is built in with the rear caliper, such as Audi/VW. The 997, 996, and many other vehicles use a drum brake style of parking brake so setting it after bedding in your brakes is fine. The reason to not set your parking brake for vehicles that have the integrated rear brake system is because once the p-brake is set, it can cause a hot spot on the rotor where the the entire rotor wont cool at the same rate and it can deposit more compound specifically on that spot that can cause buildup and judder with longer use as the pads are engaged on the rotors. This is also applied to an EPB (electronic parking brake) system. The EPB though a separate component clamps pads on to the rotor itself instead of the hat structure as drum brakes do.