trapp

I have a 2011 GS
CARBOTECH xp20/XP10 PADS
Castrol SRF fluid
steel brake lines
cooling ducts

Ran the morning without issues..)TODAY)

Started the afternoon and started to get fade in the pedal early in the session....Stopped and bleed the lines...

Next session....still the same problem....if I tap the brakes before the brake zone then they are firm. It doesn't happen at every brake zone...it seems to need a tap before the brake zones after longer straights..

I know it is not the fluid boiling....

I did put a new set of rotors on the front but it was doing this before I switch them( due to a few cracks in them.)

I read about this problem awhile bad on the forum but unsure how to solve it...

Is this problem in the calipers?

Please help

Thanks

Tom

SouthernSon

Wheel bearings loose causing knock back?

trapp

I don't even know what that means..


Some times I have to double pump the brakes to get firm pedal just driving around the padlock...I know its not the fluild...

sperkins

Pad taper. Swap the pads side to side and it should get better after a sesison or two.

trapp

After reading more this could be part of the problem...not an easy fix

SouthernSon

As tolerance develops between the caliper and rotor one finds that the pads themselves can get pushed back into the caliper further than they need to be. Therefore, when you push the pedal, the travel has to first take up the empty space before making contact with the rotor. This can sometimes lead to pedal going all the way to the floor. If the bearing is getting loose, the rotor can 'wobble' and lead to excessive knock back of the pads. I have experienced this while hitting kerbing.

I replaced bearings with SKF.

Falcon

I agree with Scott. That'd be the first thing I'd do.

CGZO6

Are you running the titanium heat shields between the caliper pots and the stock style padlets? If so, ditch the heat shields until you get some one piece pads. Padlets and heat shields don't mix well when the padlets wear unevenly (first hand experience here).

Supercharged111

Inside to outside or wheel to wheel? If wheel to wheel, do you keep the pads associated with the inside inside and outside outside?

sperkins

LF to RF and inboard to outboard.

1ED1

Broken hub. Most likely left front.

sperkins

I got that wrong. If the wear is even (overall thickness), swap them side to side, but not inboard to outboard.
If the wear isn't even, swap them inboard to outboard on the same caliper.

Bill Dearborn

Not sure how well that would work with padlets. My padlets tapered depending on what position they occupied in the caliper. Even then the brake pedal didn't seem to be affected by the taper I saw.

Bill

KNSBrakes

Knockback is more noticeable after an S section.

The rotor is on the other side of the bearing from the caliper. Bearing tolerance or hub bending will take the rotor with it and bat the pistons back into the caliper. You then have to pump a bit to get the pistons back out.

Many race calipers have a light pressure spring behind the pistons to do this for you.

Bills Z06

That's the first thing I would try

Jason

Left footing your brakes near the end of a long straight is not a bad idea even if you think you have fixed the problem.

trapp

I have the heat shields..but I also run the one piece pads...XP20's

Adam@Amp'dAutosport.com

Do not run heat shields.

trapp

I don't think they are apart of my current problem...I will remove them before next event..

Tom

trapp

Explain please..