I wanted to post this thread as a public service...


Here's the story. If you don't want the story, just skip to the following paragraph and read from the subsequent one...

I was switching back to stock rear rotors and needed the factory caliper bracket mounting bolts. I went to the local Chevy Dealer's Parts department. I described what I needed and the Parts person went into the computer to look up the part number. He went through several different views but came up with nothing. I then went home, photo-copied a page out the GM Service Manual to show him exactly which bolts I was talking about. He calls me a few days later, tells me he has them, but upon going back to the dealership, it turned out they were the wrong bolts. I gave up and corresponded with Gene Culley of GM Parts House and he was able to identify and ship me the correct bolts. While the bolts were in shipment, the dealership called me and said the found the part number, but I had to decline at that point.

For any of you who don't want to be in the predicament described above, the Caliper Bracket Mounting Bolt part number is,

GM #14084051





Interestingly, the GM Service manual says these are supposed to not be re-used... I doubt people throw these way. They were over $4 each.

 

Good job man! Some of these guys at the parts desks don't seem to try very hard. I've had similar situations with those guys. My opinion: mediocrity ad laziness. It's never as important to them as it is to you!

 

I have re used mine at least 100 times.....
I run D+S rotors for the street and solid for the track....

Buy a set of dies and run the bolts through them after each use...
It cleans them up and removes the lock tite.
bracket bolt = M14 x 2.0
Caliper pin bolt =M8 x 1.25

 

I can't see replacing the caliper mounting bracket bolt . The manual does state to discard after removal. Maybe for the fact that these might stress after tightening @ 125 lb ft? I would recomend replacing the pin bolts because they are so small & could be overly stress easily. caliper pin bolts, part #14067559. Tighten @23 lb ft.

 

I think there is a name for bolts that stress under torque and are not supposed to be reused. I'll try and find it and post it. I have reused mine.

Can an engineer guy jump on and explain. At what point (torque) do the bolts become non-reusable. I'm finishing a restoration and replaced most factory bolts with stainless steel, but some I didn't replace.

Also, how do they figure what torque should be used for a bolt...especially when it is getting lock-tited.

 

Thank you for the business and mention. I'm not sure why he couldn't find a diagram. It is in group 4 with the caliper illustration.

 

Torque to yield

 

 

Acetone and a wire brush is very good for removing old thread locker too.

 

Mechanical engineer at your service.....basically, it depends on what the bolt is made of as to how much torque it would take to make a bolt no longer usable. In my experience though, it is VERY rare to design something such that once you torque a bolt, you can't take it out and retorque it any more. I've never seen it done in practice. I believe they did it on the ZR1 engine (the first ZR1) for some reason, but I can't remember why. If you think about the caliper bolts, they are under stress when you are braking, so I sure as hell hope you haven't distorted the bolt by torquing it, because then you're heading for a disaster!

I think the reason they say not to reuse them is because (I think...I've never actually bought the bolts) they probably come with driloc on them, which is like loctite. Once you take the bolts back out, the driloc is shot and it won't glue the bolt in any more. If you don't constantly remove the calipers (as in if you just do a brake job every several years), I would just clean up the bolts and put loctite on. If you do HPDE's, etc. and are constantly changing, I wouldn't bother with loctite. I've talked to several guys who don't use it and I've never heard of one coming loose.

Torques are figured by the size of the thread. Various handbooks will give you the right torques for all of them (materials matter here too).

I WILL caution you that while stainless steel doesn't rust, and that's nice for looks, it's not always as strong as steel (like grade 8, for instance). Don't replace a bolt with anything weaker. If it's something like trim screws, big deal, but I wouldn't go SS'ing load bearing bolts. That's asking for trouble.

 

 

I agree the motive behind replacing the bolt is probably to make sure full strength lock-tite gets used on the replacement.
I have re-used mounting bolts without lock-tite and have never had one come loose.
The manual also recommends you replace the caliper pin bolts, and GM brake shoes come with a new bolt, but unless they are pitted or corroded, I just clean them up and relubricate the sleeve with silicone grease, and reinstall.

 

I can see reusing the mounting bolts. Those caliper pin bolts should be replaced, as far as I'm concerned. There like close to 1/4" in dia. & calls for 23 ft lb of torque. You over torque once or twice and I gurantee they will break off. Ask me how I know. The problem w/ these smaller bolts once stressed may not break when installing, but break sometime later, and w/out warning of course. I think for our baby, we should replace these two bolt/per caliper. Just my 02 cents. By the way I may be calling these bolts by the wrong name. The two bolts that I'm referring to are used to mount the caliper to the caliper mounting bracket. GM part # 14067559

 

There's at LOT of legal CYA stuff that GM puts forth as "necessary" in their recommendations. Very common throughout many industries.

 

/\ never thought of that.....great idea. Thanks

 

and alot of it is

 

I'm about to replace brake pads on my '04 C5 this weekend. This will be my first brake job on any corvette, but I've done dozens of these on other cars over the last 30 years. Two questions please:

1. Are these "caliper bracket mounting bolts" the two bolts - one at each end of the caliper - the two usual bolts that I always run into every time I remove calipers when I'm doing a brake job?.

2. I occassionally encounter a caliper that allows me to change out the pads without removing the caliper. Makes it really easy. Are my calipers like this?

You know, all you guys could bring your vettes over to my driveway and we could knock out all these brake jobs in about 30 minutes.

 

I've reused my bolts many times. I just make sure to remove all the old LocTite before reinstalling them.

 

I think I have answered my own questions from reading other posts...should be pretty typical. Y'all can still join me if you want. I have a LOT of tools.

 

My dealer wants $10 per bolt. Ecklers has them for $9. The washer is $6. I think reusing is the way to go.