LS1/f-body rear brake swap

LS1/f-body rear brake install:

Before swapping the brakes, I relocated the shocks (see pic). I’m not sure if the LS1 brakes will clear the shock in the stock location, but if they did I would assume it would be a very close fit. On a stock height vehicle the calipers might clear the frame rails, but my car is lowered and extra clearance was needed to prevent the frame from hitting the calipers on a hard launch or harsh bump. I had previously notched my frame for wider wheels so there was no issue there. Other than those two issues, the swap is a straight forward and a fairly easy job. Also, I believe you will need to run 16” or larger wheels to clear the calipers; my 15” Weld wheels would not clear the calipers.

Parts needed:
The donor brakes can be removed from any F-body, 1998-2002, V6 or V8.
I picked up the parts from a local salvage yard, $40.00 for everything.
There is a sensor on the backing plate (for ABS) that will need to be removed, you can discard it, unless you can figure out how to use the ABS function on our cars.
Caliper assembly, including the short rubber stock brake line, and the “banjo” bolt that holds the brake line to the caliper.
Rotors.
Backing plate, be sure to keep the four bolts/nuts that are on the donor car.
Brake fluid
Gear oil
I also added longer studs while the axles where out (NAPA P# 641-1581) ½” longer than stock. These are not needed but it is easy to do while the axles are out.
Adjustable proportioning valve (I’ll elaborate on this later)

G-body mods:
Remove wheels, drums, and all brake parts associated with the drums leaving the brake line attached and the backing plate on for the time being.
Remove: rear-end cover, bolt for king pin, king pin, c-clips and pull axles out.
Cover the ends of the axle tubes with duct tape to keep trash/cuttings out of the tubes.
Disconnect brake line from wheel cylinder, plug line to keep fluid from getting everywhere.
Remove backing plate.
I used a sawzall to cut the top of the bracket on the rear end (see pic). I cut it directly below the large hole. Use a grinder to smooth the edges and also to round or chamfer the top two corners, you can use the LS1 backing plate to check for clearance here.
NOTE: I put the LH caliper on the right side of the car and RH caliper on the left side, this positioned the e-brake bracket so I could use my stock e-brake cables, and to mount the calipers on the rear of the axle rather than the front like the LS1s.
Clamp the backing plate on squaring the two mounting plates to each other while keeping the backing plate centered on the axle.
After getting the plate clamped I drilled the four holes through the axle plate using the four holes in the LS1 backing plate as guides. I used a 3/8 drill for this.
Bolt the backing plate on using the four LS1 factory bolts.
Clean off any shavings and remove the tape covering the axle tubes, install axles.
Slide rotor on, mount caliper to backing plate, and put wheel on to check fitment.
If all looks good, install c-clips, king pin, kingpin bolt, cover, and fill with oil.
The stock steel brake line will screw into the LS1 rubber brake line. I did have to move the stock steel line to the front of the axle to make the connection nice.
Some have done the next step differently, but I chose the adjustable proportioning valve for ease of use.
Next I removed the stock proportioning valve (on inside of frame on driver’s side).
I installed a T-fitting for the front brakes, basically straight from the master cylinder to the front brakes.
Install adj. prop valve between line coming from mc to the rear brakes.
After all lines are tight, bleed brakes and check for leaks.
Next is just setting the prop valve to where the front brakes lock just BEFORE the rears.
As for the e-brakes, I made brackets to support the cables (see pics) and adapters (see pics) to go from the stock cables to the “hook” on the LS1 brakes.
The e-brakes work awesome.

Side notes:
I am running vacuum brakes, LS1 front brakes, and 17” wheels with Nitto’s all around.
I definitely have no issues with stopping now.

more pics
and a link to the mod for the LS1 front brakes:
http://www.turbobuick.com/forums/brakes-suspensions-tires-wheels/172762-ls1-brake-mod.html

Nice Pics. Been wanting to do this one myself. But why did you relocate the shock? I did see, you said, you notched the frame. Also, did you put in a residial valve in the rear brake line?

what shock relocation bracket is that?

I built the shock bracket myself, serves two purposes: with lowering springs the shocks where bottoming out on launches and to move them inboard to clear the calipers. I figured I could kill two birds at once this way. I had read a few other posts about the shock hitting the caliper, so it was easy enough to make a bracket to clear.
No residual valve, so far I haven't had any problems. The car is not my daily driver so I haven't put alot of miles on since the swap.
"bruce" has done significant work to his car and might be able to give ya more details on prop valves and res. valves.

That is just plain sick! Very nice work, it looks great!

Thanks

looks familiar what wheels are those?

Intros
http://www.turbobuick.com/forums/brakes-suspensions-tires-wheels/186699-new-wheels.html

TKGN1 looks good....

Congrats

Just thought I would add your car is awesome!!!!!!Love the stance and wheel/ tire combo.

Nice job!

Last summer I did the Blazer rear disk swap on the early a-body rear axle thats in my car . I did the same with the combo/prop valve. I heard it can be gutted but I eliminated it anyway. I put the adjustable proportioning where the combo valve used to be. Works good! One thing to note is the Blazer disks are 11.6in. I test fitted a 14x6 olds ralley wheel and it fits over the blazer disks and calipers. A residual valve is not necessarily needed with disks but if the calipers retract alot a low pressure residual would reduce brake pedal travel.

HOW Did You Make Those CLIP Brackets???
Also Can You Make More Shock Relocation Brackets?

Just an update on using 15" wheels on the rear with the LS1 brakes.
Found out my Weld pro stars WILL fit.....
But, I have to run 1/2" spacers and do a little filing on the caliper housing. Neither of the two seem to pose any problems.
I will get pics up later on the little bit of modification.
Hope this helps those who want to run 15s with the LS1's.

Todd

another option on these brakes. You can order just the shock relocation bracket from Baer Brakes part #6801105 they are $21.98 plus shipping. This would help sort out some of the LS1 brake swap problems. Just need to see what else i can use for the e-brake hook up?

I was wondering if that part was available for individual sale. thanks man.

i have a jpeg of the part from Baer if anyones interested in putting it up on the board. i'm not sure how to post pics.

Send it to me, I'll see if I can post it.
tkay@accmachtech.com

ok, i just sent it to you

Well, I can't get the freakin pic resized to fit, sorry. Pretty simple bracket and for $21.98 from Baer it seems like a very good choice if you are going with the LS brake swap.
If you want a pic of it, let me know and I'll send it out.
Thanks for the pic 78monte454.