Brake Shudder After Installing PFC 08's

[MNGo4M3]

We installed new PFC 08 pads in my Father-in-law's '16 M3 Comp today, but when taking it out to bed in he got pretty severe brake shudder. We went back and checked all brake setups and everything seemed to be installed correctly. We swapped the pads out for OEM pads that were on there and everything was back to normal.

Has anyone ever dealt with this or know what the potential root cause could be?

Also, the driver front pad could actually wiggle front to back slightly when installed even after the bedding attempt. Could there be a quality issue in the pad eyelets that allow too much wiggle or is that normal?

My FIL and his brother are convinced they are incorrect pads because there isn't "wing" weights on the back that help prevent them from going forward too far, but I've seen tons on here use the pads and others install them online without the OEM style wings.

Any advice would be greatly appreciated! First track session is in two weeks and would love to throw my set on, but now gun-shy...

[melanthius]

This is typically caused by old pad material still bedded into the rotor, while also being somewhat incompatible with the new pad material.

In order for brakes to work optimally you need the pad material on the pad to be the same as what is bedded into the rotor.

You have a couple of options.

1. Attempt to scrape old pad material off by dragging the pads against the rotors (brake+accel at the same time) - keep doing this for a while, followed by serious brake bedding session

2. Take the rotors to a shop and have them resurface the rotor, followed by serious brake bedding session

[maddmatth]

Originally Posted by melanthius

You have a couple of options.

1. Attempt to scrape old pad material off by dragging the pads against the rotors (brake+accel at the same time) - keep doing this for a while, followed by serious brake bedding session

2. Take the rotors to a shop and have them resurface the rotor, followed by serious brake bedding session

Could potentially take sandpaper to the rotors? I've heard of this working, but might take a lot of effort.

[clutchdj]

Have these pads. No issues they just squeal like a pig when cold I like them. They need to get up to track temps in order fir them to work correctly ; sounds like an install error could possibly be the case. Mileage on rotors?

[MNGo4M3]

Thanks all for the responses. I put the same pads on mine tonight on one side just to test and they worked perfectly fine. Great stopping power and even zero squeal (at least thus far).

Seems like the buildup likely is the issue for him. Will have to figure that out down the road, but he'll stick with OEM pads for now.

[m3elmo]

PFC-08 could shudder a bit but they are an aggressive pad that should "clean" the rotor of any old material, then after it beds in it should be back to normal but squeal a bit since it's more of a track tire. I can't speak to the F80, but I used to swap back and forth between PFC08 and Hawk Street pads on my E46 all the time, just needed to do a good bed in process each time is all.

[m4forum]

You can dry sand the rotors with fine sand paper or scotch brite both sides of the rotor before the bedding procedure. never had issues.

[JustJames]

Yup - buildup is the issue. I go through the same thing every time I swap these out for a track day. You’ll love the performance when hot though, much more braking force and fade resistance than stock. Stock pads are not up for serious track duty at all.

[adam996GT3]

Definitely pad build up. I had a similar experience after the brakes warmed up on the track.