Official: Brake Pad Knock Back Thread

[Vegas69]

Kinda, I got the tapered bearing axles a few weeks ago but they were machined wrong. I took some measurments and sent them back to moser. They paid for shipping each way and the repair. I just got them back last Friday and proceeded to put them in but noticed one of the wheel studs got boogered up in there lathe and now I'm waiting on a stud. I'll be racing Sunday and that will be the true test. There is definitley no end play now in either side. I'll update you guys one I drive and race Sunday.

[crazycarl]

Originally Posted by Vegas69

Kinda, I got the tapered bearing axles a few weeks ago but they were machined wrong. I took some measurments and sent them back to moser. They paid for shipping each way and the repair. I just got them back last Friday and proceeded to put them in but noticed one of the wheel studs got boogered up in there lathe and now I'm waiting on a stud. I'll be racing Sunday and that will be the true test. There is definitley no end play now in either side. I'll update you guys one I drive and race Sunday.

How did the weekend go? I am waiting with baited breath and a poised pen and checkbook.

[Vegas69]

It was better but still not fixed. For normal street driving it's fine and an improvement of a roller bearing. Once race time comes around I lose about 2-3 inches of pedal after a couple turns. It's more managable but not what I hoped for when I bought the brakes. If you are getting ready to buy and rear end, make sure it's a tapered setup or even a full floater if you plan to race a bunch. If I knew then what I know now......

[Cris@JCG]

Sounds like a brake pad issue.. If you are not having problems on the street but then comes race time and you are losing some pedal.. What is the part # on the pad you have right now? You need to find pads that have a higher coefficient of friction when you get them hot when autocrossing or open tracking.. More than likely you have a BP10 or 20 which will fade after a couple of laps.. street pads..

What brake fluid are you running? I hope you are not running dot 5 silcone..

I have a car in the shop that is set up for open tracking with smaller rotors, calipers & tapper bearings & have never had the customer complain about losing pedal or pad knock back

Originally Posted by Vegas69

It was better but still not fixed. For normal street driving it's fine and an improvement of a roller bearing. Once race time comes around I lose about 2-3 inches of pedal after a couple turns. It's more managable but not what I hoped for when I bought the brakes. If you are getting ready to buy and rear end, make sure it's a tapered setup or even a full floater if you plan to race a bunch. If I knew then what I know now......

[Vegas69]

Originally Posted by Gonzo

Sounds like a brake pad issue.. If you are not having problems on the street but then comes race time and you are losing some pedal.. What is the part # on the pad you have right now? You need to find pads that have a higher coefficient of friction when you get them hot when autocrossing or open tracking.. More than likely you have a BP10 or 20 which will fade after a couple of laps.. street pads..

What brake fluid are you running? I hope you are not running dot 5 silcone..

I have a car in the shop that is set up for open tracking with smaller rotors, calipers & tapper bearings & have never had the customer complain about losing pedal or pad knock back

Hey Gonzo,
I read your PM and was going to look into the pads before I replied. I'm pretty sure they are BP10's. I looked recently and checked them on Wilwoods site. They are street mild track pads. It's not the pads even though braking improves with heat. I can replicate it easily on the street by doing a slalom. The pedal engagment point drops 2-3 inches. I'm running Wilwood Dot 3 fluid.

[Cris@JCG]

I would try some 15E or 15B pads.. I would not run BP10s for agressive street driving or autocrossing.. I have tested all of Wilwood pads & these are the ones that have worked the best for me!

Don't rule out pads!

Originally Posted by Vegas69

Hey Gonzo,
I read your PM and was going to look into the pads before I replied. I'm pretty sure they are BP10's. I looked recently and checked them on Wilwoods site. They are street mild track pads. It's not the pads even though braking improves with heat. I can replicate it easily on the street by doing a slalom. The pedal engagment point drops 2-3 inches. I'm running Wilwood Dot 3 fluid.

[Sieg]

Originally Posted by Vegas69

The car still has to much body roll and the brake pad knockback is still slowing me down.

This has been going on too long! How much could the excessive body roll be contributing to the lateral load on the caliper?

How much would 1" smaller rotors reduce the knockback vs how much performance would you sacrifice?

Is front spindle deflection a contributing factor?

You've probably done numerous hours of searching and reading on the subject and already seen this but:
http://www.stoptech.com/tech_info/wp_knockback.shtml

One way to possibly isolate the issue would be to test with active knickback springs in the suspect calipers.

This has to be very frustrating after a couple years, numerous hours and dollars.