Caliber broke off while driving tonight

[Dylanhat]

Tonight was driving up to my brothers place in Green Lake. Was just past the Mercer Island Tunnel on I-90 west and my front left wheel locked up. Thankfully there weren't any cars to the left of me so pulled over into the HOV lane (?). After closer inspection noticed that my front left tire was done for and that my caliber had broken off. The first bolt on the Wilwoods broke off while the 2nd one sheered off. Do you guys have any ideas on why this occured? Whatever it was I am fine and can all be fixed. Attached are some photos of the caliber. BTW have had brakes for a while.

Thanks!

[c.d.iesel]

YOUR LUCKY TO BE ALIVE !

major installation fuck-up

calipers and mounts just dont fall off cars

i see bolt thread marking in one hole and not the other

lets see photo of the other side from all angles

so we can see alignment of parts........

[Dylanhat]

More photos:

Trying to show that there are grooves, the nut is stuck in place

Nipple destroyed (what cut into tire?)

Showing how warped the nut is

Chunk gone

Caliber sitting on spare at the side of the highway (wish I took more photos off what it all looked like)

Will get more info on all this tomm. have a good night and stay safe

[rogerspeed]

the original calipers were mounted with shoulder bolts, your caliper was mounted with a full thread bolt(s) as you tightened the bolt to the reciever on the spindle it was threading into the calipers, bottom line the bolt sheared under braking as there was stress and play from not being tight enough and/or the bolts not being strong enough; I've had stock bolt loosen and fall out, but not shear

PS - was a washer missing on installation, does anyone have thoughts on the aluminum itself being a contributing factor

[Dylanhat]

Was curious what condition my tire was in because I thought it was punctured I found out this:

The groove that runs all along the rim was caused by the nipple on the caliber I believe.

[tim385]

Hmmm Im running the same on my race car , so are a lot of other people I guess , Obviously they are the supplied bolts ? Did you loctite them in ?I would guess a bolt or two may have been a bit loose , ....maybe I should have a check of mine before next race meet .Are you running your calipers in front of the axle or behind ?Im pretty sure you can fit them either way .

[roadhog0]

You're running 15" wheels correct? Those arent the standard E30 weaves which are 14" and dont clear this caliper setup are they?

[bob02]

I could be wrong, but the hardware store 8.8 bolts are suspect to me. Shouldnt they be 10.8?? Shear strength. You need a supervisor for q.c. on the important stuff.

[Scott Sislane]

Was curious what condition my tire was in because I thought it was punctured I found out this:

The groove that runs all along the rim was caused by the nipple on the caliber I believe.

wowsa... I bet we all check our caliper bolts today.

[Stu]

Man, that is scary, to have your wheel lock up at freeway speed. Glad you're OK. The car can be fixed.

[Napes]

About a year ago I had a caliper bolt come loose and that allowed the caliper to tear up the backing plate. Luckily, I was driving fairly slowly on city streets when it occured.

As mentioned above, check your bolts for correct tighness. The torque is more than I would have expected, once I checked the torque tables. I don't know about aftermarket calipers, but stock ones require 58 - 69 lbs/ft of torque.

Bob Napier

[flyingjolly]

whoah, scary

[OriginalOwner]

"scary" is way too calm a word for that episode.

Cheers,

Carl

[oldguy]

betcha $10 that if it poked a hole in the rim like that, the caliper is also bent and will require replacement.

[Tommy]

Original mounting bolts are at least 10.9 grade, maybe even 12.9. Those 8.8 full thread bolts may be one reason at least but I would still look for something else. On the other hand over torqued low grade bolts is enough to cause it alone.

Tommy