RPO 684/687 Differences :The Details

[John N.]

Re: RPO 684/687 Differences :The Details

Franz
Thanks!!!
(1) Where do I buy my "Pickett" spring slide rule?
(2) Has it been established when the fans were added to the HD brakes?
Regards

[John N.]

Re: RPO 684/687 Differences : SPRINGS

Franz

I wonder what kind of brake springs were used on my 59 Buick LeSabre which has its original finned drums.

Joe

Joe
I took apart eight of those Buick backing plates and finned aluminum drums. (Potential use on street rods). Interesting springs, eccentric anchors etc. Next time you are in Tulsa we can go thru the parts.
Regards

[Dick W.]

Re: RPO 684/687 Differences :The Details

Joe, if my memory serves me they were both aluminum with iron inserts. Been a long time since I build a hi boy

[Steven B.]

Re: RPO 684/687 Differences :The Details

I always wondered why the Buick brakes weren't used on the Corvette as the base for a HD setup. Any one know? I assume they will the fit with no problems

[Jim L.]

Re: RPO 684/687 Differences :The Details

I always wondered why the Buick brakes weren't used on the Corvette as the base for a HD setup. Any one know? I assume they will the fit with no problems

The Buick drums are 12" ID, not 11" ID like on the Corvettes. The outside diameter would have been correspondingly larger.

It's entirely possible they wouldn't have fit within the ID of the Corvette wheels.

It's also possible the drum assembly (aluminum case plus steel friction surface insert) wasn't rigid enough to withstand the force of the brake shoes without becoming slightly bell shaped.

Jim