jlucas

Ok guys, this one has me stumped. I think I'm pretty much done with track days for this season, so I went and ahead and swapped my OE pads and rotors back on. These have only been used together as a set and never with any other pads. I have dedicated track pads & rotors.

Problem is now, when I first apply the brakes, the car tucks it's nose to the left front just a little before the braking evens out and it will track straight under the brakes. I went back through and did a brake bleed on all 4 corners again. No effect. It's almost like one of the calipers is operating on slight delay. None of this behavior was noticable before the pad & rotor swap. I would have certainly noticed it at the track because with quick brake application the front will tuck to the left by 6-12 inches. With slow brake application, it almost just feels like hitting a rut in the road while braking.

Anyone have any ideas of what it could be? Hopefully I'm not first one to have come across this.

freefall

I'll guess that you spread the front right caliper slightly and until the pad wears to match (tapers), it will pull left.

AU N EGL

sounds like caliper spread or braket spread.

davidfarmer

did you match the pad location (both side to side AND inside/outside) to the original spot with each rotor? If not, wear would be an issue.

If that's not it, it could still be a fluid issue. Unless you have a piston sticking, I would think any spread issues would be similar side to side. No problems BEFORE the switch back I assume.....

jlucas

No issues before the pad & rotor swap. No taper on the track pads that came off the car.

I could pull the right front off again and check it out.

gkmccready

Did you make sure the slider pins were still nice and smooth and lubed?

Allthrottleandsomebottle

That would be my guess..............I always remove the pads and use a #2 pencil to mark LH/RH. After 4 swaps between OEM/ZO6 pads on the OEM rotors all has been fine after a good 20 stops of rebedding the pads in after each swap

What fluid, rotors (assume ZO6 pads) and how many sessions?

UstaB-GS549

Hose off rotors and let dry for an hour or so. Drive around block. Pad contact pattern or lack thereof will show in the rust on the rotor surface.

I'm always trying to use up old tapered pads by driving them on the street and have never encountered pulling due to this. I have noticed that rotor rust indicates only partial pad contact for a week or two. Heavy braking will probably distort caliper enough to get pads flat to rotor.

jlucas

Well, you can't really call this pad taper.....


I don't even know how it's possbile but the upper tang on the inboard pad of the right front caliper was hung up on the edge of the caliper carrier bracket. I'm still baffled on how this was could even happen. Thanks for everyone's suggestions.

Anyone have a 1/2 used set of non-tapered stock pads they don't want anymore? I hate to throw the whole set away.

UstaB-GS549

So....

did it leave an uneven wear pattern on rotor?

jlucas

Nope, it's only been on the car that way for about 100 miles.

varkwso

Wow! Never seen that before. I just tossed all my partial sets up at VIR.....they were pretty well used up though

Allthrottleandsomebottle

I haven't either.......but I would have though murphy would have had you done at least one by now....Jeff
My analysis seems its the inboard pad.......A top or bottom tang did not get put in the caliper bracket slot when reinstalled........OR you do have a cracked brake caliper bracket which allows it to fall out of the slot

jlucas

I think I've got a 1/2 used stock set on the way.

Bad Machine

WOW! That's odd!

sleeper02Z06

I'm pretty impressed that the pad material stayed together with the backing plate peeled back like that!!

Joe