Author Topic: brake pad knockback  (Read 1285 times)

Offline crewchief

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brake pad knockback
« on: May 17, 2016 - 05:14:33 PM »
Just installed "13 wilwood 6 piston caliper kit on my '70 Challenger. I am experiencing brake pad knockback after turning while street driving even at very slow speeds turning back and forth or when autocrossing. If you hit brakes right after turn first pedal has excessive pedal travel then on next push pedal is up and firm. I did not have problem with previous 10.75 wilwood brake kit. Only change front brakes, rears are still 4 piston 11" brakes with green bearings. I have front bearings as tight as possible without being too tight.




Offline HP2

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Re: brake pad knockback
« Reply #1 on: May 18, 2016 - 09:58:37 AM »
Didja call Wilwood to discus with them yet?

Offline burdar

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Re: brake pad knockback
« Reply #2 on: May 18, 2016 - 10:35:56 AM »
Just thinking out loud...What brake hoses are you using?  Did they get changed when you upgraded to the larger kit?  Is it possible they are too short?  When you turn, they are "pulling" on the caliper and slightly compressing the pistons?

Offline crewchief

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Re: brake pad knockback
« Reply #3 on: May 19, 2016 - 04:11:15 PM »
Yes did talk to wilwood, they kept saying it is either in the back(never had it before the new front brakes) or need to find out what is flexing causing it ?? So does that mean my spindle flexes or there new aluminum hub or rotor flexes??? 

Offline Chryco Psycho

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Re: brake pad knockback
« Reply #4 on: May 19, 2016 - 09:15:15 PM »
Weird for sure
both the caliper & rotor are mounted to the spindle so it will have to be the spindle or the hat holding the rotor flexing ,, is the wheel surface area where it pinches the hat minimal ?

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Offline crewchief

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Re: brake pad knockback
« Reply #5 on: May 23, 2016 - 10:35:48 AM »
I may have got it better for street driving, but haven't raced it yet. I got the trusty service manual out and used the exact procedure using inch pound torque wrench that was in the manual. Bearing setting is a little tighter than what I originally had it and tighter than we were taught threw the years, you know the old tighten it down and then back off a hex of the nut??  We will race over the weekend and find out.

Offline GoodysGotaCuda

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Re: brake pad knockback
« Reply #6 on: November 06, 2016 - 09:23:50 PM »
I may have got it better for street driving, but haven't raced it yet. I got the trusty service manual out and used the exact procedure using inch pound torque wrench that was in the manual. Bearing setting is a little tighter than what I originally had it and tighter than we were taught threw the years, you know the old tighten it down and then back off a hex of the nut??  We will race over the weekend and find out.

Did you get this sorted out? I am looking to buy front/rear Wilwoods.

Thanks!
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1976 Dodge Warlock
1972 Barracuda - 5.7 Hemi + T56 Magnum

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Offline 1 Wild R/T

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Re: brake pad knockback
« Reply #7 on: November 06, 2016 - 10:08:16 PM »
Tapered roller bearing will take allot more preload than you'd expect... 
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