BAD-L88

Hi,

I have this up in the factory cirrect forum but thought I would add it here as well.

I was wondering if anyone could tell me the correct casting numbers for J-56 front calipers?

I have come across someone with several "2 pin" calipers but some of them may be converted from single pin. I need to verify what is what by the casting numbers.

Thanks,

B-L88

Rowdy Rat

My understanding is that Delco-Morraine did the exact same thing... They used the same casting for both the standard and J-56 calipers; the only difference being the machining operations involved.

Casting numbers for your 1969 calipers should be 5452270 (front, inner), 5452273 (front, outer), 5452281 (rear, inner), and 5452284 (rear, outer).

Regards,

BAD-L88

So you are saying the original casting numbers on J-56 calipers are the same as the casing numbers on standard calipers?

I was under the impression that they were different but that's why I am here.

Rowdy Rat

That is what I have seen and what I have heard from others more knowledgeable than myself. The only differences in the calipers that I'm aware of are the pistons, the front brake pads, and obviously, the front brake pad retention method.

The pistons on the J-56 calipers used an insulator which mounted on the face of the piston. I'm relatively certain that they were used on all pistons for both front and rear calipers.

The brake pad friction material was bonded to the backing plate unlike the standard production pads which was riveted. The rear pads were otherwise similar to the production pads. The front pads used an inconel (a very high temperature nickle alloy) backing plate with the top edge of the backing plate bent at a 90° angle to prevent warping.

The front calipers used two long cotter pins to retain the brake pads due to this ridge (it also necessitated removing the boss for the standard pad retention pin). The rear calipers used the production pin to retain the pads.

These are the best brake photos I have of a relatively unmolested '69 L-88. The numbers coincide with my previous post (I wrote them down when I took the photos).





Hope this helps!

Regards,


[Modified by Rowdy Rat, 3:13 AM 12/30/2001]

BAD-L88

RR,

Thank you VERY much. This should be exactly what I need.

Unbelievable that I ask an obscure questions and not only does someone come up with answers, they come up with close-up photos!!!

Long live the Corvette Forum!

Rowdy Rat

You're very welcome!

Actually, I'm looking forward to seeing photos of your car when you have it completed... Sure sounds like one interesting Corvette.

I saw your post in the resto section after posting this. Yes, there is a difference between 1966 and 1969 calipers. The 1965-early 1967 used the first design casting whereas the late 1967-early 1972 cars used the second design casting (the third design casting covered late 1972 through the end of 1982).

Casting numbers for the first design calipers are 5465954 (front, inner), 5465952 (front, outer), 5465902 (rear, inner), and 5465905 (rear, outer). Like the second design castings, these were used for all applications (standard and J-56) so the information Brass has given to you in the other section is correct for a 1966 J-56 car.

Regards,


[Modified by Rowdy Rat, 11:46 AM 12/31/2001]