S10 4x4 rear disc brakes

spidereyes455

spidereyes455

Master Mechanic
Mar 6, 2013
361
63
Northeastern PA
I did this swap several years ago on my GP. I used everything from a 2wd blazer and had no interference issues the shocks even bolted up in the stock location with no adapters required. I was also able to make the blazer e brake cables work. Im not sure if there would be clearance issues with the 4wd backing plates mounting the caliper at the front. Though I do know that both types mount in the same position relative to the center pumpkin of the rear, the reason for the deeper rotor hat on a 4x4 is simply due to the axle flange sticking out further from the housing than a 2wd. So if the calipers wont hit the frame mounted forward of the axle you can just get 2wd rotors and it will fit.
 
@BurnoutsandRotorblades

@BurnoutsandRotorblades

Greasemonkey
Apr 9, 2017
113
28
Las Vegas, Nevada
I cant find any 2wd rear disc blazers at the local junk yards. Im buying all new calipers, rotors, caliper brackets and pads. Does anyone know if the 4x4 backing plates will work on the rear with 2wd calipers, brackets, rotors and pads? plenty of 4x4 blazers in my yard and pretty much all i need is the backing plate that bolts to my 8.5" rear end since im going to buy everything else new.
You can use 100% of the 4x4 stuff except; the disc itself. As said above, the axle is longer and the hat is bigger on the 4x4 making it unusable. using the 4x4 backing plates will relocate the calipers to the bottom rear of the axle which will net you some clearance between the caliper and frame. something in short supply when using the 2wd backing plates. The only downside is the caliper will be a little more exposed to some road debris. As long as you're not doing a ton of offroading with your Body, you should be fine. you won't have any problems bleeding because the calipers are universal and the 4x4 calipers have the line on bottom and the bleeder on top. Hope it helps.
 
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M

mobileaudio25

G-Body Guru
Jan 12, 2012
518
43
columbus, ohio
You can use 100% of the 4x4 stuff except; the disc itself. As said above, the axle is longer and the hat is bigger on the 4x4 making it unusable. using the 4x4 backing plates will relocate the calipers to the bottom rear of the axle which will net you some clearance between the caliper and frame. something in short supply when using the 2wd backing plates. The only downside is the caliper will be a little more exposed to some road debris. As long as you're not doing a ton of offroading with your Body, you should be fine. you won't have any problems bleeding because the calipers are universal and the 4x4 calipers have the line on bottom and the bleeder on top. Hope it helps.
Perfect, I’m going to go pull the backing plate from one of the 4x4 blazers that mounts to the axel housing/rear end.

Then I’m going to buy this new 2wd kit . The 4x4 backing plates with work with this 2wd kit right? It will just relocate the caliper position.

https://www.jegs.com/i/Power-Stop/419/KC2008/10002/-1
 
Longroof79

Longroof79

Rocket Powered Basset Hound
Oct 14, 2008
10,074
113
Gainesville, Fl
I did this swap several years ago on my GP. I used everything from a 2wd blazer and had no interference issues the shocks even bolted up in the stock location with no adapters required. I was also able to make the blazer e brake cables work. Im not sure if there would be clearance issues with the 4wd backing plates mounting the caliper at the front. Though I do know that both types mount in the same position relative to the center pumpkin of the rear, the reason for the deeper rotor hat on a 4x4 is simply due to the axle flange sticking out further from the housing than a 2wd. So if the calipers wont hit the frame mounted forward of the axle you can just get 2wd rotors and it will fit.
I assume you're also running the 2wd front brake assembly. How do you rate the braking overall? ...and what master cylinder are you using?
 
spidereyes455

spidereyes455

Master Mechanic
Mar 6, 2013
361
63
Northeastern PA
I assume you're also running the 2wd front brake assembly. How do you rate the braking overall? ...and what master cylinder are you using?
Yes I am using blazer brakes on the front as well. I think braking overall is excellent, on par with newer cars. I used a prop valve from an 84 el Dorado with 4 wheel disc's and a master from an 81 Trans Am with 4 wheel disc. I originally used the caddy mc and wasn't happy with the pedal feel or performance, the TA mc uses a larger bore and now the pedal feels great. The only real gripe I have is the power assist seems inadequate to me now though I'm sure a b body booster will solve that.
 
Longroof79

Longroof79

Rocket Powered Basset Hound
Oct 14, 2008
10,074
113
Gainesville, Fl
Yes I am using blazer brakes on the front as well. I think braking overall is excellent, on par with newer cars. I used a prop valve from an 84 el Dorado with 4 wheel disc's and a master from an 81 Trans Am with 4 wheel disc. I originally used the caddy mc and wasn't happy with the pedal feel or performance, the TA mc uses a larger bore and now the pedal feels great. The only real gripe I have is the power assist seems inadequate to me now though I'm sure a b body booster will solve that.
Thank you! I appreciate your reply and feedback pertaining to your brake configuration. Looks like an adequate brake booster might be in your future. I'd be interested to hear how you make out.
I've heard from other people that the B-body master is the ticket. I just recently bought an installed the RHD Blazer master cylinder. I don't quite know what to think about it. Honestly, I'm not overly impressed with it. I have also replaced my brake booster with a G-body dual diaphragm unit.
However, I'm still using drums in the rear.
 
spidereyes455

spidereyes455

Master Mechanic
Mar 6, 2013
361
63
Northeastern PA
Longroof79

Longroof79

Rocket Powered Basset Hound
Oct 14, 2008
10,074
113
Gainesville, Fl
I've heard of others using the b body master cyl with good results as well. I chose to use the TA because it is specifically for 4 wheel disc unlike the disc drum b body unit and as a bonus looks almost completely stock since its an aluminum type with a plastic resivor.
https://www.rockauto.com/en/catalog/pontiac,1981,firebird,4.9l+301cid+v8+turbocharged,1250873,brake+&+wheel+hub,master+cylinder,1836
It makes sense using a MC specifically for 4-wheel disc brakes. I always thought the difference was in the combination valve and not so much the master cylinder. :unsure: interesting. Old dogs can in fact learn new tricks. Thanks for the link.
 
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@BurnoutsandRotorblades

@BurnoutsandRotorblades

Greasemonkey
Apr 9, 2017
113
28
Las Vegas, Nevada
I took all the brakes and the MC from the same 2000 Blazer. I didn't touch the combo valve and don't run any type of proportioning valve. I just transplanted the whole system and it works. The brakes are nice and firm even under hard braking and I have virtually no fade.
 
jakes87SS

jakes87SS

Master Mechanic
Jul 25, 2017
333
93
ohio
im not sure about s-chassis but my 3rd gen camaros were pretty dang easy to swap to
 

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