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Discussion Starter #1
I installed a new wilwood big brake kit on the 69. I got the car back from the alignment shop where they also installed a few New brake lines that were giving me fits. Took the car out for its shakedown run and the car shakes under braking like the rotors are warped. Last night I went through to see if anything was loose which it wasn’t.
Either these rotors we’re screwed from the beginning or when the shop took it out to test the brakes romped the crap out of them.
Anyone else ever have a similar issue with wilwood or any other type of disc brakes and a solution?
 

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I think there's a specific process for bedding new pads. Not sure that could cause a wobble like you're feeling, but I'd give Wilwood a call and see what they have to say about it.

Do you feel it all the time or just under hard braking? Maybe the struts are loose?
 

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I went through years of trying to figure out a rotor warp issue on my wife's minivan so I'm familiar with the problem. The issue is most likely that your brakes weren't properly bedded. I'd recommend that you grind the rotors down and re-bed them.

david
 

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Discussion Starter #4
I think there's a specific process for bedding new pads. Not sure that could cause a wobble like you're feeling, but I'd give Wilwood a call and see what they have to say about it.

Do you feel it all the time or just under hard braking? Maybe the struts are loose?
nothing is loose on the suspension which is good. I’ll probably have to try to bed the brakes and see how it goes. Hopefully I can get it taken care of
 

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Do the rotors bolt to the hubs/hats in your kit? If they do, you can check if any of those bolts came loose.

Rusty
 

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Jack and shake & push/pull the wheel(s). Is it loose? Could be the rotor spindle was not properly seated and torqued... (I made this mistake - and fixed it.)
 

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What pad material? I was getting frustrated with the brakes on my 2014 F150 crew cab doing that I took the rotors off and took a flap disc to break the glaze. I noticed a film on the rotors that was difficult to remove. I was talking with @GT289 about this. He explained that ceramic pads deposit a film on the rotors to react with the pads that's "suppose" to help. But depending on how evenly it leaves this film or junk as I call it will effect braking.

Next time I did brakes I went to www.bestbrakes.com got custom made rotors and Bear pads I think. I'm going to say it's the pad material and you may need to clean up the rotors and do bed them according to the manufacturer.
 

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Adherent or adhesive friction material? Hard to know what Wilwood is using on the OP's pads.
Both of these types transfer material to the rotor to some extent. It is the even-ness of the transfer that effects whether
you experience brake judder (warped rotor syndrome).
If brake pads are bedded in in a funky way, you may be getting the "wobble" that the OP is describing.
Hard to know for sure. I used to clean up the rotors with 120 grit garnet sandpaper and attempt to re-bed the pads.


ex-Global West GM
1991-1995
 

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Discussion Starter #9
I’m am using the stock pads wilwood uses. Last night I checked for wobble with and without the tire and there was none. All bolts were still torqued down as I painted a line over each bolt to see if they came loose.
The rotor is the two piece style that had to be bolted together.
 

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I have the exact same problem with my Wilwoods. They shuddered even before the bedding process. I pulled the discs off and repacked/torqued the bearing and checked for loose components and still does it. I haven’t gone back and torn into it again. The only thought I had which may not make sense is that I possibly didn’t torque the disc to the hat properly? Maybe warped it, but when I watch other people install them it doesn’t seem to be an issue.
 

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If they shuddered even beforehand...... here’s an idea.... call Wilwood.
Let us know what they have to say. I definitely would like to hear their thoughts.

ex-Global West GM
1991-1995
 

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I finally stopped my minivan from shuddering by installing much bigger brakes on it. It weighs almost 6k empty and then you pack a family in it and the rotors really heat up. Plus the calipers only have one piston and the rotors are one piece. I actually think with Wilwood brakes our cars could have the opposite problem. I think a typical 302 Mustang is around 3.5-4k in weight and often we're driven with one person. With Wilwood the rotors are two pieces to prevent heat distribution and 4-6 piston calipers. So all this means that bedding the brakes is going to require really heating them up which is hard with such a light car and such heavy duty brakes.

david
 

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Discussion Starter #14
I have the exact same problem with my Wilwoods. They shuddered even before the bedding process. I pulled the discs off and repacked/torqued the bearing and checked for loose components and still does it. I haven’t gone back and torn into it again. The only thought I had which may not make sense is that I possibly didn’t torque the drum to the hat properly? Maybe warped it, but when I watch other people install them it doesn’t seem to be an issue.
When did you purchase your kit? I got mine last fall and I know they were behind on their orders and rushing things. This is my second install with the same kit, and didn't have issues with the first one. This makes me think something is boogered up from them. I torqued all my bolts per their requirements, and everything is still properly torqued into place.

I highly doubt it my wheel bearings since there's no play anywhere.

I got off the phone with wilwood support and he suggested rechecking the alignment between the caliper and rotor and to NOT base the alignment numbers with the pads in. That i can honestly say I didn't do but did my best to keep everything flush when installing. Looks like that'll be my next checks
 

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I got off the phone with wilwood support and he suggested rechecking the alignment between the caliper and rotor and to NOT base the alignment numbers with the pads in. That i can honestly say I didn't do but did my best to keep everything flush when installing. Looks like that'll be my next checks
That would surprise we as a contributor but I have been surprised before....

ex-Global West GM
1991-1995
 

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Discussion Starter #18
So I checked it as per their instructions. The passenger side was a washer off but the driver side was good. took it for a drive and it was a lot better, but still present. I started going through the brake in process, but traffic was picking up.
753975
753976
 

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Discussion Starter #20
Another update: yesterday I contacted wilwood and told them the changes that were made and that the shuttering effect is still present. They suggested trying to pull a shim and try it. So I did, and it didn’t yield much better results. Their only other offer was for me to pull the rotors and have them checked to see if they are warped. Hopefully I can get them checked today.
 
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