More than once I'm sure someone here has upgraded the rear disk brakes on their 86-87 9-bolt from the "iron" calipers to the 88-92 PBRs.

Since the original rear brakes on my 87 IROC 9-bolt are getting pretty weak, I'd like to do the PBR upgrade and 12-inch rotors.

I've read through the techh articles here about brake upgrades and have not determined if the 88-92 PBR calipers require new backing plates when installing on the 86-87 BW 9-bolt rears that originally came with disk brakes.

It appears upgrading my 9-bolt 87 rear using the 88-92 PBR calipers and 12-inch rotors might be a direct bolt-on using the existing backing plates and mounting hardware, with the addition of a new emergency brake cable.

Before tearing my daily driver apart for extended down-time, I need verification from someone who has actually done this swap.

How about it -- any 86-87 9-bolt brake upgrade guys can help me?

If I need replacement backing plates, what are my options?

 

Hey, Duck, I guess I didn't understand your PM. There is a considerable difference in backing plates between 10.5 rotors and iron calipers (88 and earlier, I believe) and 11.7 rotors with alum calipers (89-92). No direct bolt-on. You may be able to source the correct backing plates from AndyZ28 or Ed Miller. The following link will show you the pre-89 backing plates from a 10-bolt (the 9-bolt is the same except for the bolt pattern, I believe--at least that's the case for the 89-92 PBR version); the link will also show you the correct backing plate for either a 9- or 10-bolt upgrade.

https://www.thirdgen.org/techbb2/sho...hreadid=249098

JamesC

 

It's actually '89-92 PBRs..the '88s still got the iron calipers.

You'll need 9 bolt backing plates and the brakes for a '89-97 car as they're the same.

Let me know if you have any questions on it, I've done a few swaps..


Ed

 

Thanks both ebmiller88 and JamesC -- my original confusion was caused by not realizing the pictured 9-bolt backing plate is a required upgrade part and not merely an example of how it differs from the 10-bolt backing plate. Had the parts years wrong too, ack.. Ok, I'll follow the lead for replacement backing plates first, looks like all the other parts are easily obtainable everywhere. Really appreciate the help!