Motor Trend article
Apparently one of the Boss 302 testers had a brake clevis pin snap, and the pedal itself was incorrectly installed, resulting in zero brakes. Luckily all Boss 302's have actual manuals (hooray for Ford!) and the driver was able to go down through the gears and save the car.
The only thought is that maybe the master cylinder had been pulled and replaced, and whatever monkey that hooked the brake pedal back up did it wrong. Except nobody has any proof that the MC ever came out of the car, so it could have equally been a production-line error.
Bravo to Ford for shutting down the Mustang line and trying to figure out the issue though.
how do you snap a clevis pin? Those things are usually pretty stout and with lots of support
mad_machine wrote:
how do you snap a clevis pin? Those things are usually pretty stout and with lots of support
Probably because it was installed incorrectly. The article says that the brake rod is a u shape and the pedal goes in the middle, so if a broken clevis does happen, the pedal catches inside the u and still operates the master cylinder. This one was installed to the outside of one of the u's, so it likely put a ton of shearing force on that clevis. The car was tracked around Laguna Seca like that! 
tuna55
SuperDork
4/26/11 11:54 a.m.
As a former OEM supplier who has sen one extremely, :: interesting :: event occur during a press day, I can wager a guess that this was tampered with after the factory was through with it. I don't mean sabotage, I mean idiocy.
well.. idiocy knows no bounds. We even see it here on occasion.
Outside the U it is cantilever arrangement.
Ford needs to Poke Yoke that thing!!!
tuna55
SuperDork
4/26/11 2:56 p.m.
mad_machine wrote:
well.. idiocy knows no bounds. We even see it here on occasion.
I'll just say that you'd assume that air would fill tires. Nitrogen even...
Things people do boggle the mind. It wouldn't surprise me one bit if some local shop was hired to do a tune up or some such thing and put together the clevis wrong.
^ I wouldn't be so sure. $0.12 or otherwise, it's a "SRC" (safety related component) and there would normally be all sorts of extra QC steps associated with that.
Did they add a data logger to this car? Maybe someone hooked up a brake POT & reassembled it worng. Also, I can totally see that as a blind job, reach under dash & feel the plunger / hole (heh heh).....
KJ
tuna55
SuperDork
4/27/11 9:56 a.m.
Kendall_Jones wrote:
Did they add a data logger to this car? Maybe someone hooked up a brake POT & reassembled it worng. Also, I can totally see that as a blind job, reach under dash & feel the plunger / hole (heh heh).....
KJ
That's pretty likely - although "they" could have been anyone between the factory and MT.
Giant Purple Snorklewacker wrote:
Giant Purple Snorklewacker wrote:
That pin looks like plastic over a thin screw.
The pin on my E30 is a solid 12mm rod like 99% of every pin/clevis combo I've ever seen used. The one in my Chevelle is 1/2" rod - I'm not sure why anyone needed to change the basics - probably to address some customer complaint about a squeaky pedal.
serously, where's the metal? it looks like its not only smaller, but only the middle part actually sheared. i can understand covering a normal pin with something to quiet it down, but that looks looks like they replaced it.
