Z06 Whisperer

I came off the track this week after a session and noticed right away my driver's rear brake (I have stock rear callipers on my '02 C5 Z06) was making an awful noise. Pull in to pit and see my calliper has slipped back and away from the rotor and that one of the mounting bolts is gone!!! Only one of the corners of both of the pads were worn down at a sharp angle (they were new ) and even a corner of the calliper itself had been worn down. The rotor was a bit scored but not badly. Found a replacement bolt and went back out--nothing flew off this time. (Hey I had a really busy session the one before so that's my excuse for not noticing )

How common of a problem is this? Do you all suggest any upgrades? Any other thoughts/ideas?

Thanks so much!!

John Shiels

new pit crew

Z06 Whisperer

I know, I know, that did come up! No, no that I needed a new pit crew , but that the bolt might not have been tightened.

My poor pit crew consists of the equivelent of about a half a person (I'm the one that brings that average waaaaay down )

It was a bit nuts this week though, all those silly little Porsche cup cars buzzing around. Only had to drive off the track halfway once to avoid one who ran another P car a little too hot into the turn. I'm like "the heck (and I'm using a nicer word here) with you two, I'm going around the both of you until you can decide which way you're gonna spin." LOL Yeah and that's the session I lost my bolt. :o

(PS I want a cup car LOLOL)

Olitho

Nope, that has never happened to me... yet.

I have done a lot of other weird things though, both on and off the track!

94ZR1#444

Ask TimZ06 about his experience at CMP back in March of '04 at CMP....

varkwso

I saw it happen once before on a C5 that was prepped by a dealer .

I went out and ordered a few bolts "just in case".

The bolt got loose is all....

I also want a GT3 Cup car

TRACKMAN2

it hapens all the time ... ive lost a front caliper mountint bolt twice found them finger tight a mess of times just be sure to check them after and prior to every track day...and dispite tightening the heat and cooling cycles are so great esp for hard brakers they just come loose some use locktite but thats a pain when you have to remove them to chane rotors all the tiime.. ive also lost 4 link bolts,shifter bolts the battery cables come loose.. , i'm thinking of the good old safty wire.... required on all superbike caliper bolts its a snap to undo and keeps you from loosing parts.....i nut and bolt my car every three months..

UstaB-GS549

4th season with Z06 & never have come loose. I would guess that it was just forgotten.

Bill Dearborn

Which bolts? The caliper bracket bolts or the caliper guide pin bolts?

Bill

Z06 Whisperer

Sorry for the slow response, but I didn't know the answer and wanted to research it.

What I did is go to my trusty '02 red covered Service Manual, volume one. You all can grab yours and follow along here.

In the section covering Disc Brakes there's a section called "Brake Caliper Repalcement-Rear" on 5-72 and 73. On 5-72 the lower diagram(unfortunately unlabeled or tagged the verbal description of the part) shows these bolts being removed, the only ones refered to in the procedure and they are indeed called the "calliper guide pin bolts". It was the top one of these that I lost. Sorry for any confusion I may have caused!!

Anyway, it shows on 5-82 and 83 the procedure for "Brake Caliper Bracket Replacement-Rear". Here it shows and discusses the "brake caliper mounting bracket bolts". What I found really curious here is the warning at the top of 5-83 that states "The brake caliper mounting bracket bolts must not be reused. Replace the bolts with new bolts whenever the bolts are removed or become loose." Can anyone tell me why this is and if they do it each time?

If I was smart I should go through and read the Shop Manuals--maybe I should put them in the bathroom. OK that was a really bad joke attempt.

Thanks!

BQuicksilver

The topic of replacing these bolts as recommended has been discussed many times here, and most don't replace them and have no issue. I'm in this crowd as well.

That being said, I have torqued my guide pin and bracket bolts maybe 50 times now. I'd imagine it's time for some new fasteners. Still, no issue here to date.

Bill Dearborn

The manual recommends not reusing either of the bolts. If you buy the OEM brake pad kit you will get replacement guide pin bolts. Both sets of bolts come from the factory with threadlocking material on them. I re-use my bolts especially the caliper bracket bolts as they are fairly expensive for a bolt.

What happened to you is not common but is something that worries me everytime I work on my brakes. Your caliper problem probably came about due to not tightening the guide pin bolt properly. As you know the guide pin has to be held with an open end wrench while the bolt is tightened. Due to the rubber sleeve covering the guide pin it is easy to mess up while tightening the bolt and I always double check my work to ensure I have them tightened properly.

Bill

Cobra4B

I use blue loc-tite on the guide pin bolts and torque to 23 ft/lbs and red locitie on the caliper bracket bolts and torque to 125 ft/lbs... never had an issue.

WNDOPDLR

I have often wondered about this. If you go to the Locktite web site you will see that either the red or blue products have low (350 degrees or less) melting points. Doesn't the Locktite become a lubricant at that point rather than an aid? I don't know what the temps in that specific location are on track days, but I know that my rotors get a lot hotter than that and the residual heat travels. I choose not to Locktite the bolts, but have never been 100% sure of my reasoning.

Cobra4B

Blue is lower than red... the caliper braket bolts are always a huge PITA to break loose.

Bill Dearborn

I have stopped using Locktite and haven't had a problem with the bolts coming loose and it makes it some what easier to loosen the caliper bracket bolts while at the track.

Bill

Z06 Whisperer

I don't know if anyone is slightly compulsive like me , but it drove me nuts to wonder what happened to the bolt itself.....

......well it showed up not long ago hanging out of the drain hole in the rear brake duct!!!! Isn't that wild!! (just in case inquiring minds wanted to know LOL). Thanks!

Aardwolf

I don't replace them on mine, and I use a small bit of anti-seize instead of the locktite. I do check them, also check the spindle nut while you are there.

BrianCunningham

Safety wires and locking tabs are a must on a racecar.

Especially around dissimilar metals.

TommyBoy72

FWIW, this happened to me last track day about a month ago. I swear I had checked those very recently prior to the event. However the DR side front upper caliper guide pin bolt was lost during the 5th session of the day. I found another one the next day and replaced it only to discover my caliper rebuild kit had them included for each corner. It's now in a toolbox of spare stuff I take with me to the track.