Brake failure

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Joined
Apr 27, 2012
Messages
4,765
Reaction score
102
Location
Nashville, Tennessee
My Car
1973 Q code Mach 1
Last night I had a pretty serious brake failure. I'd spent the weekend widening the wheel tubs to handle the 325-45-17 inch tires and had reinstalled my lowering blocks and all the other necessary mods to make room.

I worked at a shop about 25 miles from my house. and as I got home last night and put my car in reverse to pull into my garage I heard a loud bang as if I had hit something.

What actually happened is the passenger side rear brake caliper apparently lost one of the bolts and when I hit the brake in reverse the caliper slammed into the inside of the rear wheel. I pulled into the garage just as the tire was going down and jacked it up enough to see the caliper laying in the wheel, the brake hose ripped loose and a hole in my rim. I could also see the aluminum caliper mounting bracket (part of the baer conversion kit) had one corner sheared off.

I don't know if the forward fastener backed out or failed or if the aluminum bracket was somehow damaged. I'll do the autopsy tonight and get more information. None of the work we did was anywhere close to the brakes.

Bottom line-whatever happened it is my responsibility and therefore my fault. Double and triple check fasteners!

 
Sorry to hear but glad the only casualties are parts.

Could have been a lot worse going down the highway or the track.

Post pics of the carnage when you can.

 
"CARNAGE" I think I just figured out what to put on my next license plate!
Me too

Put " DON'S " on the new plates and sent it to me.

It is causing you too much trouble. I'm just thinking of your health here, wouldn't want you to get an ulcer or something from it.

Glad you were home and almost stopped when it happened.

 
Don't worry, I have a sense of humor about it. I was glad my tire appeared to get through this without damage since it cost twice as much as the wheel. I'm replacing the aluminum brackets with steel and I'm going to safety wire those MF's

 
Well here are a few pics. Bolt is missing as expected. Rotor looks okay, I'll have to get it on a machine and check.

looks like I will not get my core charge back on the caliper!

nqz7na.jpg


Think I can jb weld that hole up?

ok94xf.jpg


Bracket damage

dc3n6p.jpg


 
"CARNAGE" I think I just figured out what to put on my next license plate!
Me too

Put " DON'S " on the new plates and sent it to me.

It is causing you too much trouble. I'm just thinking of your health here, wouldn't want you to get an ulcer or something from it.

Glad you were home and almost stopped when it happened.

Now that goes to show you what a great forum member Don is. Given the ever rising costs of health care, for him to be concerned enough to worry about you getting an ulcer or some stress related illness speaks volumes. Once you put the "DON'S" plates on it and send it to him you should feel much better. Lol

Glad you did make it home before you had your trouble. That could have been a major Cluster F*** if that would have happened at speed on the highway. :)

 
Just put a tube in there it will be ok, gee I thought crap like that only happen to me, I feel your pain

 
Sorry to hear that. I am waiting on new 2pc rotors for the car from Baer. If you need a set of rotors I will be selling them cheap! Under 100 miles.

 
4mm, I think the rotor is okay, but I'd be interested, let me know when you are ready to sell.

Looks like about 550.00 worth of parts if I don't have any unseen damage. Almost everything is enroute (just need a brake line)

Before the failure, the car was running beautifully and the new tires were really allowing me to accelerate harder than ever. By the time the tracks open up I should be ready.

 
Yes Jeff that really sucks! Remind me never to use Aluminum for high stress parts. Looks like a metallic fracture to me in the picture. Aluminum might be OK in a Race car for weight, but on a street car???

A rear brake up-grade is on the wish list for me and seeing your problem is very useful information. Costly to you, but could save me that hassle and maybe my life.

All the best getting it fixed,

Geoff.

 
Just to be clear, I doubt the aluminum would have failed if a fastener had not gone missing. I am using Mustang Steve's brackets which are steel to replace the Baer ones and the bolts at issue will be red locktighted and safety wired. I had the system apart last year, but let someone else do the original install. I don't know if I might have trusted their assembly of the bracket and not taken those parts apart or not. The bracket broke because a fastener was not present-I assume it vibrated out at some point on my drive home-I see no evidence of damage to the thread or the presence of locktite. I feel like a moron.

If doing a rear disc conversion, many will make 15" wheels unusable. Changing out the Master Cylinder is a must and some amount of tinkering is likely to be necessary. If I were to do it again, I'd upgrade my front brakes and keep my rear drums for any initial modification.

 
Just to be clear, I doubt the aluminum would have failed if a fastener had not gone missing. I am using Mustang Steve's brackets which are steel to replace the Baer ones and the bolts at issue will be red locktighted and safety wired. I had the system apart last year, but let someone else do the original install. I don't know if I might have trusted their assembly of the bracket and not taken those parts apart or not. The bracket broke because a fastener was not present-I assume it vibrated out at some point on my drive home-I see no evidence of damage to the thread or the presence of locktite. I feel like a moron.

If doing a rear disc conversion, many will make 15" wheels unusable. Changing out the Master Cylinder is a must and some amount of tinkering is likely to be necessary. If I were to do it again, I'd upgrade my front brakes and keep my rear drums for any initial modification.
I see. That does clear up what happened and I would definitely follow your current plan if I do go the rear disc route. Just no room to take chances. Another alternative that was previously suggested would be to use 11' drums and skip the disc problems. These cars are so light in the back end that too much brake can be a bad thing. I currently have an adjustable rear brake valve as I converted to front discs. It is set to minimal rear brake bias.

 
Last night I had a pretty serious brake failure. I'd spent the weekend widening the wheel tubs to handle the 325-45-17 inch tires and had reinstalled my lowering blocks and all the other necessary mods to make room.

I worked at a shop about 25 miles from my house. and as I got home last night and put my car in reverse to pull into my garage I heard a loud bang as if I had hit something.

What actually happened is the passenger side rear brake caliper apparently lost one of the bolts and when I hit the brake in reverse the caliper slammed into the inside of the rear wheel. I pulled into the garage just as the tire was going down and jacked it up enough to see the caliper laying in the wheel, the brake hose ripped loose and a hole in my rim. I could also see the aluminum caliper mounting bracket (part of the baer conversion kit) had one corner sheared off.

I don't know if the forward fastener backed out or failed or if the aluminum bracket was somehow damaged. I'll do the autopsy tonight and get more information. None of the work we did was anywhere close to the brakes.

Bottom line-whatever happened it is my responsibility and therefore my fault. Double and triple check fasteners!
Wow, what a bummer....glad the damage wasn't any worse than it is. I've seen this twice on bass boat trailers with disk brakes...in those cases, one of the caliper bolts came loose and dropped out allowing the caliper to wedge against the wheel. One guy's locked up when backing up...the other guy wasn't so lucky...his bound up going forward and ruined wheel, tire, and caliper. They ended up using a sledge hammer to knock the wheel off because the caliper was wedged in so tight.

 
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