[kweevuss]

I was in the process of swapping my front rotors to new ones. Preemptively I ordered new bolts for the calipers, as I already have taken them off a few times to swap in the front cooling ducks and brake shield removal and wanted to put fresh ones in (for track days). I'm a little concerned about the differences in what I received.

From what I understand reading online, and according to gmpartsdirect, the part number for the front caliper bolts should be: #11611085

This is what I ordered, but you can see in the attached pictures there is a slight difference in length for these bolts. The original is ~63mm, the new is ~57. Also the bolt head on the original is 18mm, and the new is 22mm.

Is this what should be expected? I did just also order bolts from my local chevy dealer, and they confirmed the same part number above. I will be picking them up tomorrow hopefully when they are in. I'm concerned they will be the exact same dimensions of the gm parts direct ones though.

Do I have the right part numbers or should I be looking for something else?

Also one last question, assuming I get the right bolts, or these are correct the blueish color on the threads, that is already thread locker correct? I would NOT apply any more loctite on these?

Thanks!

[Bumbleboy92]

The blue thread shouldn’t need loctite IIRC.

I believe you should use the bolts that are same length as your OEM bolts, I’m pretty confused on it still too as I had to order some for my 4 piston upgrade. The issue is that there’s two different 4 piston brembo brakes that fit two different rotor sizes.

There is the SS 4 piston brakes that fit the SS 13.6” rotor.

Then there’s the old and discontinued LT 4 piston brakes that fit LT 12.6” rotor.

I’m guessing you accidentally bought the bolts for the LT version as the parts list literally doesn’t distinguish them even by picture. It’s all a part number game, I’d return and look at part numbers through the parts sites. I’ll try to find it myself too.

I had a extra burden when looking as the LT had 3 part numbers (single piston, LT brembo, SS brembo). It’s a pain to see the right one, I actually have the bolts I bought which I think are meant for the LT brembo (the brembos I have yet to install) so when I get home I’ll post part number and size for that as well

Edit:

So I ordered 11548406 which is listed as the LT bolt while the one you ordered (11611085) is listed as the SS bolt which should be fine on paper. I'm not seeing another option for front caliper bolts. From other threads in the past it seems like 11611085 is the correct part for SS 4p brembos. Is there any identifying marks on your old bolt?

I still have to measure my bolt when I get home to make sure

E2:This thread tells the single piston LT and 4p brembo bolt as 21mm for reference

Originally Posted by DirectTo

... On the back of the caliper, you can see the two 21mm bolts holding the caliper on. Using your breaker bar/wrench, break them loose. Remove them with the socket and a ratchet. ...

... On the left, the factory Brembo bolt, on the right, the factory LT bolt. Both are 21mm heads, the Brembo bolt being very slightly longer and having more unthreaded area at the top. Notice both have remnants of factory red thread locker. ...

Sadly the pictures that member posted expired so we got SOL there.

Many threads are listing the 085 part number as the correct 4 piston SS bolt. I'm unsure why the size between your original and this part are different but if all else fails try to put it in both old/new bolts and if it either doesn't fill all the threads or extends too much then I guess you have the correct answer.

On the off chance, 11570948 is listed as the rear caliper bolts which are 18mm head and 55.5mm long....

E3:

Well I'm not resourceful and just realized RockAuto has a good description on each bolt.

SS 4p Front - 11611085 - 21mm head, 45mm length

LT 4p Front - 11548406 - 21mm head, 42mm length

Rear (single and brembo both?) - 11570948 - 18mm head, 55.5mm length

E4:

A new revelation, this site puts it as the old bolts you have are TTY and the new bolts are apparently not TTY but fit.

God I thought way too much into this when it was a simple 'new redesigned bolt' lol

At least someone on the future might stumble upon this and get the right bolt

[kweevuss]

Wow amazing research thank you!!! Hopefully helps someone in the future too.

So good to know on the LT options. Other than the 10.9 Zinc rating on the head of the bolt there is nothing else identifying on either of them.

That’s interesting that site lists those ones as non TTY but the factory ones being that. As far as I understood the 5th gen camaros were TTY, but that changed on the 6th Gen.

The rock auto seems to match what I have though. I only quickly grabbed a socket so they probably are closer to 21mm head and if I measure from just the head down, it is about 45mm long, so seems to match at least.

I will update the thread when my other ordered parts come in.

[Bumbleboy92]

I measured my (406) and it’s 55.56mm with a 21mm head

https://imgur.com/a/jOZDhBI

Doing this stuff definitely beats actually working so I count it as a win haha

[kweevuss]

Originally Posted by Bumbleboy92

I measured my (406) and it’s 55.56mm with a 21mm head

https://imgur.com/a/jOZDhBI

Doing this stuff definitely beats actually working so I count it as a win haha

Is that a new bolt? Or one that was taken off? I am thrown off by the color of my thread locker being blueish, and would expect it to be red like yours, unless you had applied your own thread locker.

[kweevuss]

I did get the additional bolts from the local dealer, and they do match the above replacements as well. So I did go with putting these in and hoping I don't have any issues


Here is the difference while the old bolt was installed. I never noticed, but you can actually see the old one goes past the caliper, and the new one is just about the length, so I'm assuming there is no issue with this.

[Bumbleboy92]

Originally Posted by kweevuss

Is that a new bolt? Or one that was taken off? I am thrown off by the color of my thread locker being blueish, and would expect it to be red like yours, unless you had applied your own thread locker.

My bolt is new but is apparently for the LT 4 piston kit which is smaller then the SS kit and is a different part number (11548406) compared to the SS kit bolt which kweevuss has (11611085), though since you have a SS then that would be the correct bolt. I say apparently as I haven't installed my kit lol.

I believe the original loctite is red from factory but with the new SS bolts they used blue loctite since BLANK's new bolt has blue loctite.

Originally Posted by kweevuss

I did get the additional bolts from the local dealer, and they do match the above replacements as well. So I did go with putting these in and hoping I don't have any issues


Here is the difference while the old bolt was installed. I never noticed, but you can actually see the old one goes past the caliper, and the new one is just about the length, so I'm assuming there is no issue with this.

Nice, I guess they fixed the sizing of the screw and it might've been cheaper at that point to not use TTY bolts lol