Camarored86

I have been searching these brake threads and I don't exactly see what anybody is doing on the rear brakes. I have an 86 iroc that came with disc rear and was going to convert to the C5/6 upgrade, I already have all the stuff for the front and my question is-If I do this to the rear, how do you do the parking brake? Or does anybody upgrade the rear at all? Like I said I could not find a definite answer to this question, thanks for any input.

ShiftyCapone

iTrader: (7)

You can convert to C5 rears but they aren't much better than 4th gen rear disks. With the 10 bolt you'll need a floating caliper and won't be able to use later model vette brakes. Check out bigbrakeupgrade.com

Abubaca

iTrader: (3)

The disc brakes up until 89 are the old delco-moraine brakes. Prone to locking up. Mine are currently locked open on my 88! The 89 and up has the Aluminum PBR calipers. ...they used them all the way up to 98 when they were changed to what most people consider the "LS1" brakes, as the it's the first year of the LS engines in the 4th gen. They're plenty good and will give you modern braking when used with a decent set of front brakes. I had 'em on my 89, and getting ready to swap 'em on my 88.

Give Scott at Bigbrakeupgrade a call or email. He'll get you set up right.

Denis.V

I'm in the same boat with my 86' rear disc brakes, but whit 9 bolts.

According my previous searchs, alternative is 2000 Blazer 4x2 rear disc brakes too.

Abubaca

iTrader: (3)

So here's the thing about brakes from "other" vehicles....4th gen, 5th gen, corvette...whatever. At the end of the day, if you have the means to fabricate or purchase the right bracket, you can pretty much use any caliper, on any rear axle. Don't get me wrong, I'm sure there's some exception, but you get where I'm going. Those blazer brakes look like 4th gen LS1 era brakes, though I did NOT check part numbers. It wouldn't surprise me if they were. What you want to be mindful of is, how much work will it take to swap? Is it enough of an upgrade to be worthwhile? Is it worth the MONEY? Are parts readily available? Has it been done enough to have tech help available?

Unless you're seriously competing, the aluminum PBR calipers and the LS1 era 4th gen calipers are MORE than enough brake, they're cheap, readily available and have been done over and over by countless thirdgen owners. Ed at Flynbye performance and Scott at Big Brake Upgrade both have LOTS of experience fitting many different kits to many different axle set ups. I know Ed, but he's been..."difficult" to reach now for several years. He's honest, and you get your quality parts, it just sometimes takes awhile. It's just a second job for him as far as I know. Scott on the other hand is always readily available, and was great to work with.

Buddy

Big thumbs up for Scott. Ed is great too, I have just delt with Scott and he is first class all the way.

LAFireboyd

iTrader: (3)

The parking brake for 4thgen LS1 and C5/C6 rear brakes is built into the backing plate assembly that attaches to the axle--a drum-in-hat design, nothing at all like either style 3rdgen rear brakes.

A universal, adjustable brake cable kit would be required, such as from Wilwood or Lokar(which appear to be the same products). Although, for an LS1 conversion, I think Hawk's offers brake cables that are supposed to be the correct lengths, but I've also heard they don't fit, as advertised. So the universal kit from Wilwood, which is probably better anyway, is probably the better choice.

For 10-bolt axles, complete, used, LS1 rear brake assemblies will bolt-on. For 9-bolts, they won't, but the C5/C6 rear brakes from Big Brake Upgrade will. Scott also adapts the C5/C6 brakes to 10-bolts too, in case you prefer new C5/C6 parts, instead of used LS1 parts.

Calipers for either brakes, while slightly different, are interchangeable, however, pad abutment brackets are not. So whatever you calipers you choose, you'd need abutment brackets and rotors that are specific to the brake kit.

Another advantage C5/C6 rear brakes have over LS1 is that the LS1 is 12" only. Whereas, C5/C6 supports 12" and 13" in that style, and also 13.4" in the Z06 style(w/Z06 calipers), so you can changes sizes later, easily, if there's a need or desire.

Denis.V

Does anyone know the braking efficiency of the PRB 93-97 rear calipers for the hydraulic brake and for the parking brake?

According to my local legislation and Technical Review, the braking efficiency must be:
50 - 60% for hydraulic brakes and
15% or more, for parking brake to pass the test in the roller machine.

Will the PRB comply with that standard?


Thanks in advance if anyone can reply.

Camarored86

Thanks guys, I really appreciate your input. I have options and a little knowledge to get this going.

blackbmagic

There isnt a real significant improvement by upgrading the rear brakes on these cars. Thats why many just upgrade out of convenience. The pre 89 calipers are junk, but upgrading to aluminum calipers from an LS car would be the standard upgrade.
__________________

Abubaca

iTrader: (3)

...I agree with this, however I'd look at both the 89-97 PBR rear brake as well as the 98-02 LS1 rear brake. Only a marginal difference in performance, but i think there's more work to swap the LS era brakes as opposed to the pBR. I've done the PBR swap twice, and it was easy. Haven't done the LS1 rear before, but it's worth looking into. I'd go the cheaper/easier route as performance would be similar.

QwkTrip

iTrader: (22)

Braking efficiency..... Okay, don't know how they're confirming that. Describe the test that you have to pass.

QwkTrip

iTrader: (22)

Depends upon vehicle setup. If you want to stop fast then you've got to have proper brake bias for your car. It all comes down to how your car transfers weight to front of vehicle and how much grip is available to the rear tire during braking. In general, cars with stiffer springs need more rear braking because more grip is available to the rear and less to the front.

Stock brakes suck so bad, fade so quick, that virtually any front brake upgrade will be a big improvement. The rear brakes still matter but it matters less for somebody still on stock suspension that rocks like a ship being tossed in a storm. If you stiffen up the suspension then you can actually lose braking distance and the reason why is the brake bias is wrong for your set up and you need more rear brake.

12-inch rotors are more than enough for most people and having good calipers is really where its at. Most of us using larger rotors only do so because that's the rotor that is matched to our calipers. It's not like we needed 13 or 14 inch rotors.... it's just required for the caliper we're running.

I can tell you from my own experience that C6 Corvette front brakes are a mismatch to PBR rear calipers and the brake bias is all wrong with a stiff suspension. I can't get enough rear brake - not even close. My car would stop quicker if I had done smaller front brakes. That bends the minds of a lot of people but it is true because it would improve my brake bias for better balance of front/rear braking. I've never done anything about it because I don't race and it's $$$$ to fix it, and I'll lose my SPECTACULAR parking brake that the PBR's are known for. I can tell it's not optimized but I don't demand it yet for what I do.

People really need to pay more attention to the difference between floating and fixed calipers.... We use floating calipers, folks!!! If your brakes came off a car with an independent rear suspension then odds are it is a fixed caliper. If your calipers have opposing pistons then odds are it is a fixed caliper.

QwkTrip

iTrader: (22)

If you want to estimate the brake bias of your combo then you can learn more here,

https://www.thirdgen.org/forums/brak...ng-torque.html

ChemGuy

Question on disc rear upgrade. If you use the PBR caliper bracket (Flynbye or others) what rotors do you use? My car is a 91 RS. Would I use late 3rd gen rotors or 4th gen rotors..like 93-97?

My plan now is PBR bracket, 93-97 rear calipers...no parking brake needed as its a drag car build (slow Bracket car).

Thanks.

Dan

rt66er

iTrader: (2)

These are what I used on my PBR conversion: