Dante93GTZ

iTrader: (5)

I picked up a spoiler for my 91 Formula from a guy locally - He had a pretty good selection of 3rdgen stuff, and had an '88 GTA in his garage that he was rebuilding...

Anyway, we got to talking and he mentioned he had a '91 GTA rear disc rearend for sale and showed it to me. The calipers had "Australia" stamped on them and were aluminum. (After I got home, I checked my 1991 Formula and it has the same setup, both calipers are rear biased on the rotor)

He then mentioned that his GTA had cast iron calipers on it and showed me something I'd never seen before - His D/S caliper was on the back of the rotor, the P/S caliper was on the front/forward of the rotor (His rearend was a 9 bolt if that matters). I'd never seen that before - Is that normal?

Anyway, we got to talking about PBR brakes and I'm curious; What exactly are PBR brakes? How about the caliper differences?

Twin_Turbo

iTrader: (25)

PBR calipers, commonly referred to as 1LE calipers. Std on all later models, replacing the crappy iron ones (the ones with the one leading and the other trailing the axle).

PBR is the brand name, they made the aluminium corvette calipers and 1LE front calipers too, as well as C5 7 C6 corvette std. calipers and the C5 Z06 calipers w/ the individual pads per piston.

The Baer track calipers are nothing more than re-badged Corvette HD or Grand sport calipers (available w/ grand sport & corvette script on later cars, eary had ribber versions of the J55 caliper for 13" HD rotors)

This is a PBR caliper:


The PBR calipers are so much better than the crappy delco moraines.

stock 9 bolt w/ delco moraines:


same axle upgraded to 12" (corvette rotor) w/ PBRs


more info on PBR calipers (corvette ones, JL9 & J55)

http://www.vettemod.com/forum/showpo...2&postcount=10
http://www.vettemod.com/forum/showpo...3&postcount=11

Dante93GTZ

iTrader: (5)

Thanks for the info; So am I correct, I've got PBR's on the rear of my 91 Formula? I haven't looked at them real close, I assume the rears are single piston?

JamesC

iTrader: (5)

89-92 rear discs have PBR's (alum) with the calipers to the rear.

82-88 rear discs have Delco-Moraine's (iron) with opposing calipers.

Both are single piston.

More general info in the following link, if you care to peruse it:

https://www.thirdgen.org/forums/tran...-10-bolts.html

JamesC

Dante93GTZ

iTrader: (5)

Thanks for the info! The link is full of good stuff, too!

IROC_5796

question, dont know if this is your car, but where do you find am aluminum cover for a 9 bolt? also whats with that cross arm for the panhard?

thanks.

Demonic13

iTrader: (-1)

I have a 91 camaro Z28 front and rear disc. I am getting a front 1LE kit. My rear calipers are cast iron and I want to know where to find the pbr aluminus calipers that will bolt right in place of my crappy rear cast iron calipers. Anyone know where I can get the rear aluminum calipers? Thanks

JamesC

iTrader: (5)

A 91 with rear discs should have originally been equipped with PBR's. The so-called 1LE rear set-up is a bolt-on, but does require the removal of the axle shafts in order to mount the correct backing plates. The alum calipers are available from parts stores. Or both, as well as the 1LE combination valve and parking brake cables, can be had from Ed Miller :

http://www.flynbye.com/

JamesC

Demonic13

iTrader: (-1)

I was informed in a previous form that since I have rear disc that my stock combination valve would be the same and that I did not have to change it. "Re: [LA] 1991 Camaro Z28 1LE project again, there is no "1le" rear caliper, its the g92 rear caliper. also there is no difference between the "1le" prop valve and the standard 4 disc prop valve that ive ever found.

if you already have rear discs, its the same stuff that came on the 1le cars."

As for the parking brake cable, I would have to replace it?? When iu say the PDR calipers are available at most stores Could i buy the centric remanufactures rear calipers that state there for a for a vehicle that has the 1LE performance package? Do you really think they would arrive aluminum? Thanks for all your help.

JamesC

iTrader: (5)

In searching I've found that 89-91 shows the same Cylinder, Brk Master GM 18014286. Earlier years show different masters for J50 and J65. GM, however, pretty much made them interchangeable (All have the 'quick take up' master):

https://www.thirdgen.org/forums/susp...fferences.html

There are different combination valves (if only one was needed, why would GM design valves for different applications?). For exampe:

Valve, Brk Combo (1989 2nd Des) (J50) (1990 [and also 91]) (J41, J42) GM 10136839
J41 - BRAKE SYSTEM, POWER, FRONT DISK, REAR DRUM, CAST IRON
J42 - BRAKE SYSTEM, POWER, FRONT DISK, REAR DRUM, ALUMINUM

Valve, Brk Combo (1989 1st Des) (J65, 1LE, Y82) GM 14089496
J65- BRAKE SYSTEM, POWER, FRONT & REAR DISK
1LE - PERFORMANCE PACKAGE, SHOWROOM STOCK RACING
Y82 - MERCHANDISED PACKAGE, FORMULA

All 89-92 rear disc cars (J65) have the same rear discs as the 1LE (which is why they're called 1LE, I suppose). When you order, order for the 1LE or the performance package and you should get PBR calipers. The parking brake cables for the iron Delco-Moraine calipers won't fit the PBR's.

JamesC

abray1

The thread pattern is different from 89 to 92. I put rear disc on a 92 and the threads were different and the brake line would not bolt up to the master cylinder, I had to re-use the drum prop valve.

JamesC

iTrader: (5)

There are two designs. The first design 1LE will fit metric valves up to mid-89 (my car is an 85, so this is the valve I used), the second design fits mid-89 through 92 cars.

JamesC