Just picked up a set of calipers, brackets, and the proportioning valve off of this car.

My car is a 69 coupe, can I use the brake lines, tubing, side frame valve, basically can I use the existing GM factory 69 disc system with this Seville set-up?


What do I need to make this set-up work on my 12-bolt?

take a look:

http://www.buickperformance.com/reardisc.htm

http://www.geocities.com/motorcity/6765/page11.html

If you use a 1980 Cad. Seville as the donor car, you will get 10.5" dia. rotors with the correct 4.75" bolt circle like our cars have AND both calipers wil point to the rear so that the e-brake cable deal is easier to install!

Just plug and redrill the caliper brackets to the 10/12 bolt axle flange 4-bolt spacing.

One last point is that IF you want to, plug the center hole and all four and move them all 5/8" farther out, then install 1989 Camaro 11.75" rear rotors.

You will need to shim the inner pad by using an old pad backing plate riveted to it, b/c the Camaro rotor is about .2" thinner than the Seville rotor that IF I recall right is 1" thick.

I have this set-up on the rear of my car now to match my pdqCBB 13" front big single piston set-up!!

pdq67

The post above looks like the kit I got from Stainless Steel Brakes for my 68, I was told the donor was a Cad.

pdq67....

I did get the 2 with the front/rear caliper locations; of which I disapproved of.
On the 1980 Seville units, both brackets have the caliper to the rear?
If so, will the parking brake line cables be of equal length and align with a 69 F body?
I did notice the 5 on 5 rotors; you suggest the 1980's are 5 on 4-3/4's?
I took the hard lines with the fixed end for the caliper, I suppose that line will be different on the 80 version as well??
The one link suggested the axle play, calling for the .080 plates...is this common?

take a look:

http://www.buickperformance.com/reardisc.htm

http://www.geocities.com/motorcity/6765/page11.html


Good read!

I figure there is a GOOD chance my stock e-brake cables just might hook up after I remove some slack?? Or somebody recently posted a couple of places that may sell just what we need.

Here's two of them; From Dennis...

http://www.touring-classics.com/

and from Run269...

http://www.inlinetube.com/

As for the Big Cad. vs the Cad. Seville calipers, I think you will find that the Big Cad. calipers have larger pistons so as some have mentioned are too big to balance all that well on our cars unless you use the big single piston calipers! And even then, it's still not all that good a front/rear bias..

Fwiw, I, (and somebody else), have posted the whole GM rear disc brake chart here years ago that is in onna my OLD mags so just maybe it is in the archives?? It lists doner car years, part numbers, rotor sizes, bolt patterns, caliper sizes, mount directions, etc, etc..... EXCELLENT INFO!!!

As for the backing plate shim thickness deal, I am not using backing plates b/c of the 1989 Camaro 11.75" dia. rear rotors. So I just used washers to shim my custom caliper brackets where I needed them so they were PARALLEL to the rotor face! I just clamped the caliper to the rotor and shimmed away sorta deal...

I still have to hardline my rearend as well as make another short crooked as all get-out Prop Valve to distribution block b/c my Z-Bar hit the one I fabbed earlier. What a *** PAIN!!!

For the rerarend, I figure I will either use stock Seville rubber hoses and clamp the Seville hose holders on my rearend or else use longer hardlines and "hair-pin" them so the calipers will float.

I haven't decided which way to go yet??

pdq67

PS., AND again, please remember that the Seville rotors are 10.5" with 4.75" b/c whereas the Big Cad. rotors are 11" in dia with the 5.00" b/c..

I mention this b/c the little 10.5" rear rotors looked down right funny next to my 13" fronts!!

Well , I thought this would be easier than I expected, so I will toss the seville stuff and keep the disc/drum set-up....just way too many variables!

I want to throw this out here...

If I had this to do over, I would have installed 11" Big Car and S/W rear drums on my car and been done with it!!

M/P sells a kit with everything new now as well as one can be pieced together from a Pick-A-Part yard along with new stuff.

I figure with disc's in front, bigger drums would be a very worthwhile addition since it would be a stock conversion on our cars 10 and 12 bolt rearends. (Then I wouldn't have to screw around with the e-brake problem..).....

To this day, I have never found out for 100 percent how GM put the Big Car 11" drum brakes on the, "rare as hens teeth", '65, Z-16 Chevelle's frontend??

I mention this only b/c I DO figure the 11" drum brake spindles should fit our cars UNLESS GM used Big Car ball-joints and changed the spindle tapers??

pdq67

Ive condsidered the big car drums, but I want to use my XT's!

My desire is to get a more factory look with cost considerations....

My concern is fitting anything besides the the factory drums, something in disc or drum that will clear the inside clearances of my XT rim's backside.
I belive the suggestion on these Seville caliper brackets is that they wont clear 14's.
Were JL8 set-ups designed only for the 15" YH rims' backspacing and inner circle ID?

David,

Can you answer this for him??

But I think stock '69 front disc brakes clear a 14" stock steel rim if it is rolled right in back for correct caliper clearance..

pdq67

XT's clear factory GM front discs for 69....
Usually I always see JL8's on Z28's.
I am aware that several cars that weren't Z28's to get this but, I am only going on what was suggested on the whole run of the JL8's.(Hooper's book?)

As silly as this sounds AND I am sure I will stir the pot, I swear my Salesman told me I could order 4-wheel disc's for my car IF I wanted to AND when I asked him about the price I coughed!!

So didn't!!

Just maybe he was talking about just the fronts??? AND it took us about 2 hours to go through his option list!!!

pdq67

All of these old GM setups (edit: I mean the seviles/fbodies, I don't have too much knowledge of the JL8 stuff) are very similar. It also appears many of the aftermarket setups for "small" wheels are very similar. From what I read the 'hardest' part is selecting the right MC and maybe some plumbing updates.

I have all of a 79 WS6 setup in a box in the garage. Prop valve back. I was going to put it in the 77, but I have changed my mind. I am saving them for the 67.

That one link had one error. Early 3rd gen calipers do fit under 15" wheels. I know, I retro'd them from an 85 to my old 82. Anyone who says there is no difference between the disc performace and drum performace has not gone 80-0 twice in 10 minutes.