Brake Caliper Fell off.
 

Had an "I didn't even know that was a thing" failure on Friday night:

Was slowing for a stoplight and heard a "clunk," then the car acted like someone had replaced one of my wheels with a large rock. (Made the same sound, too.) It would hold it's place on a hill in neutral and was impossible to push. I fired it up again and pulled into a driveway. I suspected the issue was in the front, but the suspension up there looked fine. Tow truck guy arrives, I start backing the car up, and he notices a clanking sound from the driver's side rear. He pulls out the jack and:

http://forums.maxperformanceinc.com/...1&d=1595786805

"Well, there's your problem." Even with this blurry photo, you'll see that the caliper is centered at 3 o clock when it was originally mounted at 9 o'clock.

http://forums.maxperformanceinc.com/...1&d=1595787035

He simply pulled the caliper off, then zip-tied it to the suspension, and I drove home on three brakes.

The next morning, I jacked her up to take a look:

http://forums.maxperformanceinc.com/...1&d=1595787272

http://forums.maxperformanceinc.com/...1&d=1595787330

In this second picture, we're looking at the caliper upside down. (The longer part of the bracket mounts on the bottom.)

There is a second anodized bracket that goes between the bracket you see here and the rear end housing. I found half of it in the street, but discarded it before the tow truck arrived. (It was next to a motorcycle chain.)

So - the brake managed to rip itself free - much like my alternator did last year. (I was missing a bracket.)

Anyone else see this happen? The tow truck driver says he's seen it a few times: usually with Wilwood brakes and once with his own car.

I'll be calling the retailer that I bought the kit from on Monday to buy replacement brackets/ask for some tips. I had these brakes installed at a shop "because I don't want to screw up something as important as the brakes," but I may be tackling this one on my own.

My drivers side (the side with the broken caliper) axle has a few milimeters of in/out play. The passenger side does not. (Both sides used to have play, but the same shop that did the brakes worked on the rear end and improved (but didn't solve) the problem.

I'm interested in your thoughts - thanks!

wow !
you got lucky ,,, glad your safe
have em fix the tranny leak running down the exhaust
and
the lower control arm bushing looks blown out also ....

Loose or broken hardware? And I suspect that is a pinion leak...

First two pictures aren't showing up, for some reason.
https://forums.maxperformanceinc.com...1&d=1595790710

https://forums.maxperformanceinc.com...1&d=1595790715

So what actually happened? It looks like bracket hardware holding the caliper to the axle housing just snapped. Can you post a photo of the other side showing how it looks when mounted?

What happened is the caliper clamped on the rotor, pulled itself free, and started rotating.

The “why” is more of a mystery. The witness mark on what was the top of the assembly is what has me confused- did the mounting bolts back themselves out? What snapped the (missing from the photos) spacing bracket? Did something get pulled up and stuck in there?

What I'm curious about is whether your calipers use spacers to mount to the bracket which in turn fastens them to the axle flange. If so, and if the mounting hardware backed out a little bit, that would put a lot of lateral load on the hardware and could lead to the failure you experienced. Without knowing exactly how your rear brakes mount up, this is just a speculation on my part.

I need to get back under there tomorrow to see if the threads on the flange are still good. I’ll take a pic of the other side when I’m there.

My guess is the bolts were never fully tightened & loosened over time....

Maybe a few Hail Marys are in order!

I was on a car cruise last on a Saturday last September to the Denny Albaugh car collection in Ankeny, IA and at the last stop sign before pulling into Denny's building one of the Corvette's lost a caliper just like you did.

The bolts had backed out - we were wondering if we'd be able to find replacements locally. Turned out the shop at Denny's collection was open and they had the bolt's and let us use a lift to make it an easy fix...

A few shots of Denny's collection:

Common when no loctite used on the bolts they come loose & shear.

Pretty exciting when a GTP car at 180 mph shatters a rotor, tears off a caliper & tosses it up through the body work.
Ping Pong between the guardrails ensues, sometimes backwards or on a bad day, upside down.
That brings back some memories!

There is a “spacer” bracket between the housing and the bracket attached to the caliper. The vendor I bought the brakes from (KORE3) in 2015 doesn’t carry them anymore, and this bracket doesn’t appear in the install instructions I have. I need to find out where I can buy just those two brackets without starting over.

loose???
 

soft brackets, soft spacers, soft washers,soft lock washers, all will be squished down and peened ,so to speak ,because they are soft and being tightened heavily and subject to much vibration,,because they are soft .not hardened,,and will lead to the bolts hold in it together becoming loose,, spend the time and money on high grade hardened hardware,,read carroll smiths book on race car hardware.he was a big advocator of safety wiring everything on a race car,i would suggest doing that on your calipers.DONT USE LOCK WASHERS , all useless..free down load on NASA fastener fabrication book. easy to find online..

Tobin at KORE3 came through for me again! He told me where I could buy these parts at Summit.

I'm shocked the pistons did not come out or at least start leaking sticking that far out. You had a tow truck there & you drove it home like that. Please tell me you have a dual master.

So I spent some time under the car this weekend figuring out how I'm going to fix all of this.

http://forums.maxperformanceinc.com/...1&d=1596575537
The mechanic had previously installed the brakes where the rotor could contact the mounting screws. He did some later work to minimize play in the rear end, but we left the same rotors on. I'm ordering some new rotors and pads from KORE3.
http://forums.maxperformanceinc.com/...8&d=1596575657
The backing plate that the rotor was bolted to. Note the shot threads from where the caliper tore free. I'll probably need to buy a new mounting plate to fix this.
http://forums.maxperformanceinc.com/...1&d=1596575792
This is the lower mounting bolt on the still-intact passenger side that tore free on the drivers side. (sideways view - to the left of that big hex screw.) Now I know why it wasn't torqued - it's impossible to get a wrench on this without removing the axles, the calipers and the backing plate. I'll need to do all of this in order to re-install the drivers' side hardware and add loctite and a proper torque to the passenger side.

I've never removed an axle before, but it looks like it's time to learn. This is a 1965 Chevy 12 bolt out of a Chevelle that was freshly built in 2013 with an Eaton posi, and has 14,000 miles on it.

Still gathering all the tools and parts that I'll need. While I'm at it, I'm going to learn how to adjust the drum-based parking brake so that maybe it will work for the first time I've owned it. (I've previously depended on shops to adjust it, and they've never been successful.)

Well at the very least, you have several shops NOT to work on your car...

The plot deepens...
 

So - I was told "you may as well buy a new backing plate rather than go to the trouble of getting that stripped hole fixed."

I looked into it: and the backing plates are only available as an assembled R and L set - with the parking brake and caliper brackets attached.
http://forums.maxperformanceinc.com/...1&d=1596684557

Yeah - I could spend $300+ on a lot of stuff I don't need, or I could find a machine shop to fix that stripped hole. Maybe they can make a thicker C clip for me to get my axle play under control too...

Back to the brakes - if they come pre-assembled, how is it the mechanic's fault that the bolts weren't torqued property, and if "Loctite must be used," why didn't Wilwood use it when they shipped this stuff?

Hmmm.

Update.
 

So the temps out here cooled enough over the weekend, (but the smoke was thick enough to hold off football workouts), that I could spend some time in the garage.

I discovered that - although the brake backing plates are shipped fully assembled - my rear end is Just under the 2.75" minimum axle offset for this kit. (about 2.69"). My installer compensated by adding these washers. (new passenger side backing plate on top of the undamaged original).

http://forums.maxperformanceinc.com/...1&d=1600111018

(or if it won't rotate, the new plate has the parking brake cable attached already.)

So - Wilwood customer service is going to help me come up with a plan to get this to work. They don't recommend using washers as spacers since washers typically aren't machined to precise tolerances. Could be an installer issue again.