Wtf is wrong here?

[GewoW]

Hey all

Been noticing this getting worse...

What should i check to see why my discs are not getting fully swept?

(AP racing kit with strap drive rotors)

I really appreciate any help.

I will be calling Stillen on Monday-Tuesday also.

It's happening on all corners....

[THE TECH]

1. Were all the parts new when you installed them?
2. Are you sure the pads are the correct model?

[Malek@MRF]

Looks like more of a problem with the caliper, not the rotor. A piston could be stuck. Unless the pads being used are not the correct ones.

[GewoW]

Im really doubting that the caliper is a problem because it's on all 4 sides. Also, all the pads were the ones suggested by Stillen...thats ive been running on the street for 2 yrs now

[jritt@essex]

Have you pulled the pads out yet? My hunch is that the pads are crumbling away along their lower edge.

[GewoW]

Originally Posted by jritt@essex

Have you pulled the pads out yet? My hunch is that the pads are crumbling away along their lower edge.

Thats the plan this weekend...we'll see what happens.

Called Stillen
They said it was probably because of unever deposit/wear with the track pads and then it shows up with the street pads. Idk how true that is.

May also try to just go do some hard stops and see if it clears up.

[jritt@essex]

Originally Posted by GewoW

Thats the plan this weekend...we'll see what happens.

Called Stillen
They said it was probably because of unever deposit/wear with the track pads and then it shows up with the street pads. Idk how true that is.

May also try to just go do some hard stops and see if it clears up.

Cool. Let us know what you find out when you pull them. Is there any difference in the radial depth between your street and track pads? In other words, is the friction material puck itself equally tall on both?

[GewoW]

So went out did some hard stops. About 10-15 hard stops, but had to stop cuz i'm still on winters. Did not really change anything. Hard braking was also not a problem, no pulling to any side or instability of any sort.

So I went back home and took apart the front right. Here are my findings. Any opinions on best course are appreciated.

- pads are flat (they are also about 1000 km new)
- pads have rust on them, transferred from the disc
- caliper looks good
- pistons look good
- rust on disc (centrally) is smooth but feels caked on
- rust on outside feels like a little lip, like the outside of the disc is slightly thicker (less than a fraction of a mm)
- when disc width was measured in the summer i was ~1 mm from max wear i.e. 50% (max wear is 2 mm from new). I am not sure what it is now because I cannot rely on a measurement given this new lip.

Time for new discs???

[okusa]

You should really keep your track pads on for a few days of street driving after you visit the track. It's the only way to clear the deposits of the rotors. The street pads never get hot enough to do the job.

[STALKER]

I think its normal, if I recall correctly, my APs did the same thing.

[GewoW]

It is also on both sides of the disk, FYI, and in the same pattern.

[CanAutM3]

As posted in the Montreal thread, I've seen this before. The reason you see a rusted portion on the disc is simply because the pad is not contacting the disc there, Just keep on driving on them, and it will progressively go away. You will need much more than 10-15 stops to get there though .

[GewoW]

Much improved after a 20 min reg drive around Montreal (ok maybe a few aggressive stops )

So this should clear up. I'll let u guys know if anything comes up!