New brakes shuddering; trouble shooting

kinkyllama · Post by **kinkyllama** » Sat Aug 19, 2006 7:42 am

I finally got the wilwood big brake kit installed but am having problems. Under braking, light or hard, the front of the car shudders. I'm not really sure what to check for other than what I've done. I checked and rechecked every bolt and nut to make sure its torqued to specs, I bled good the first time but am going to one last time when I can find a helper, I looked through making sure all the bolts/nuts/washers were in the right places, and I checked to make sure the wheels were torqued. Everything lines up well and I know the rotors arn't warped. What am I missing?

Thanks for the help guys,
Danny

kinkyllama · Post by **kinkyllama** » Sat Aug 19, 2006 9:30 pm

I reinstalled them and rebleed them and its still there. Though every time I drive it seams to be less. It doesnt shudder at lower speeds anymore.

kinkyllama · Post by **kinkyllama** » Sat Aug 19, 2006 11:14 pm

The only thing I can think of is in one place between the caliper and the caliper mounting bracket theres a small chance I used a .030" washer instead of a .035" washer

It seams the shudderings coming from the right side. Also when I slam the brakes the front right locks up and the front left doesnt seam close. The front right rotor is also much much more hot than the left after driving around the block.

Slammed · Post by **Slammed** » Sun Aug 20, 2006 12:14 am

rotors are new? if not they need to be turned other wise check the front end (tie rods ect.)

daewoomofo · Post by **daewoomofo** » Sun Aug 20, 2006 1:19 am

even new rotars might need to be turned, a co=worker of mine worked in a garage before and he said they ALWAYS turned new rotars just to make sure

GsiTurbo · Post by **GsiTurbo** » Sun Aug 20, 2006 2:42 am

Something is out of true (rotors wobble). Remove the rotors and ensure surface area is RUST FREE - there must be not dirt / debris. Also check that all the bellow / rotor bolts are torqued to specifications. Finally, retorque your wheels. If after this vibration is still present, contact the manufacturer for further assistance (replacement of warped rotors, for example). Also, check with the install manual for any special brake-in procedures.

Cheers,
Tom

kinkyllama · Post by **kinkyllama** » Sun Aug 20, 2006 4:01 am

GsiTurbo wrote:Something is out of true (rotors wobble). Remove the rotors and ensure surface area is RUST FREE - there must be not dirt / debris. Also check that all the bellow / rotor bolts are torqued to specifications. Finally, retorque your wheels. If after this vibration is still present, contact the manufacturer for further assistance (replacement of warped rotors, for example). Also, check with the install manual for any special brake-in procedures.

Cheers,
Tom

No rust. As for dirt there isnt anything more than a finger print but I'll go over them while I'm trying other things.

The only bolts I havn't checked since the installation are the rotor hat to rotor bolts but I torqued them and checked them all once before I put it on. Thing is the they only need to be torqued to 12ft-lbs each for about 8 bolts then your supposed to use locking stuff and safty wire. But I havnt used the locking fluid or safty wire for anything yet since I'm having problems with it...could this be the problem?

Did the break it correct, though it was almost impossible. The break in was strange... it required heavy braking untill brake fad occurs then letting them cool off. I just drove at 25mph with the brakes on for about 5 mins and and did 15 hard stops from 40-60mph and still did not get any fade and dont think I would have. My friend has 13" brakes (mine are 12.2" )and doesnt even get fade after a 30min track session.

The manufacturer is out of town untill Wensday which is why I came here. One of my stock calipers bleeding screw is broke so i can't drive my car untill this is sorted out. Monday I'll bring the rotors in to a shop to see if they are warped but being wilwood and brand new I doubt it.

The only thing that might be out of place on the front end is my sway bar... one of the links also on the left side is not tight but it has been that way for several weeks.

MMamdouh · Post by **MMamdouh** » Sun Aug 20, 2006 9:29 am

new rotors will always need break in... doing that right affects how long the rotors will survive.

a heat difference between rotors means extra friction at the hot caliper... it could be stuck or the master brake cylender is not delivering even amount of pressure to the calipers... i had a "turn right when braking" issue that was diagnosed as a faulty master cylinder.

is their any chance that this is the normal sound of hard braking with them rotors? heard many cars (Porschas and BMW 850) that got brake shudder but i am not sure if this is the case with big brakes kits.

bad anti sway bar bushings are said to cause front end wonder at braking/acceleration... check them as well.

MMamdouh

kinkyllama · Post by **kinkyllama** » Sun Aug 20, 2006 4:05 pm

MMamdouh wrote:new rotors will always need break in... doing that right affects how long the rotors will survive.

a heat difference between rotors means extra friction at the hot caliper... it could be stuck or the master brake cylender is not delivering even amount of pressure to the calipers... i had a "turn right when braking" issue that was diagnosed as a faulty master cylinder.

is their any chance that this is the normal sound of hard braking with them rotors? heard many cars (Porschas and BMW 850) that got brake shudder but i am not sure if this is the case with big brakes kits.

bad anti sway bar bushings are said to cause front end wonder at braking/acceleration... check them as well.

MMamdouh

I did the brake in the best I could.

The brake bias was good with my stock brakes... but I suppose it could have been off just enough where with stock brakes I wouldnt notice but with this good of brakes it shows.

It can't be normal... I dont feel very safe even driving it on the street let alone the track. The right locks up way beflre the left (even taking a left hand corner) and the car gets very violent under heavy braking.

The bushings should be good they are only a 2 months old.

I'm betting on warped rotors.

kinkyllama · Post by **kinkyllama** » Sun Aug 20, 2006 5:02 pm

They're warped... now if I can only find someone that can resurface them on a Sunday

MMamdouh · Post by **MMamdouh** » Sun Aug 20, 2006 9:31 pm

why did they wrap so fast?

MMamdouh

kinkyllama · Post by **kinkyllama** » Sun Aug 20, 2006 10:43 pm

MMamdouh wrote:why did they wrap so fast?

MMamdouh

We'll I'm 90% sure they're warped. I'll know for sure tomorrow. I called 17 shops and only 2 were open, one wouldnt do slotted/drilled rotors, the other would only do them on the car and it cost too much.

I think they came warped...theres no way in hell they warped from driving for 20mins.

Post by **Efratech** » Sun Aug 20, 2006 11:21 pm

wait till tomorrow then and call the manufactuer....

Slammed · Post by **Slammed** » Mon Aug 21, 2006 12:09 am

I dont think I have ever seen a new rotor that did not need to be turned before use its normal

kinkyllama · Post by **kinkyllama** » Mon Aug 21, 2006 10:48 pm

well it was warped... got it fixed today and installed. Just an idea of how many times I installed this big brake kit now... I just did it from jacking the car up to putting it down in less than 30mins

Its 110degrees right now and it took me about 10 stops anywhere from 45-80 down to about 10mph to get any kind of brake fade and I have crappy street pads on.