disc brakes

[ChevyMonkey]

i want to convert my drum brakes to disc brakes, front and back, but the disc conversion kits cost a butt load, i was wondering if there was any other newer chevy trucks or cars that would fit my truck (69 c/10). or maybe i could just take the front and back axels if possible, any info would be apperticted (spelling).

also im fixin to start tuning my engine, as in, new carb, intake, prolly new cam, and exhaust, if u have any input on these things as in which is the best feel free to comment, im kinda thinking about it being a sleeper, or a every other day driver.

[Longhorn Man]

As far as rear discs go, it is kinda silly onless you plan to enter a rally or something.
But that is JMO.

[Big69C20 Toy]

as far as i know anything from 73-87 will fit with the correct ball joints and outer tie rods for the front. Regarding the rear there are kits out there but as andy said it's kinda excessive unless you're doing some crazy stuff.

motor stuff all depensd on what you've got and what you wanna do.

[ebfabman]

Oh well, guess I'm silly cuz I like rear disc brakes

[imdarren]

I'm with the monkey and Eb! If 4 wheel disk brakes arent better, then how come they are putting them on so many new SUV's and trucks? I think they look better too.
Also. 45 or 50 series tires are overkill. But they look damn good too!
Just my .02
Darren

[Shane]

I'm with the others on this one too.....i kinda dig the idea of simplicity.....no drums/shoes to adjust and shorter stopping distance....but thats just me.

This pic is of a 12 bolt, '72 truck rearend using 1978 Cadillac Seville brake components. (caliper, rotor, and brackets)

[Low69CST]

There's no cheap way to put discs on the front. No disc spindles fit on your current balljoints and tierods unless you go buy some. I put 73 drop spindles on my truck. All my balljoints were good, but I had to replace them all for these new spindles. If you want to drop y our truck, your going to have to buy new spindles anyway. So you would be better off buying ones that would save your money from having to buy new joints and tie rods. Early classic I think makes a disc brake spindle that fits on your ball joints. That would probably be your cheapest route. Some people change the whole crossmember to get disc brakes. I don't like that method but its deffinately an option. Also on the back, You can either put a kit on your truck or get a while new disc brake rear end. I put a chrysler disc brake rear end under mine. I have different bolt pattern front and rear but, I liked the other benefits of the rear end, plus I get get my front rotors made to match. I think the Cadilac Seville is a good place to look for rear disc brakes. The brackets off the rear end can be made to fit our trucks and the rotors have a 5 on 5 pattern. Don't hold me 100% to this. I read a post about doing this a long time ago, but i've never researched it. Another good option is putting in a Lincoln Versailes (sp?) rear end. You get disc brakes, 5 on 5 pattern and other bennefits of having a 9" ford. There are also some aftermarket kits that work fine. I saw a post about a kit just a few weeks ago. you could search the board and find it.

I've looked at alot of this stuff, if have any questions i'll try to answer them for you.

IMO:

The whole automotive aftermarket world is silly. Who possibly needs 20 inch rims, a truck with a 6 inch lift kit, a truck with air bag suspension, or a 10,000 dollar 700 horse power engine.

[Longhorn Man]

I may have gone overboard when I said silly, however....
Discs in the rear just don't improve the performance that much.
I had a smaller car that I blew out both rear brake cylinders,and, being that I was a private in the Army (E-1) with a family, I couldn't even afford to pay attention. (I'm talking I would skip a meal every day so wife and kid could eat well). I crimped off the brake line as she slowly stepped on the pedal, (to expel all the air) and I ended up with a firm pedal.
Honestly, I was kinda scared to drive it at first, but you couldn't even tell they were gone onless you were really pushing the car hard. The only other time is if you were turning and stomped on the woah pedal.
Now, I am not trying to say it is OK to go with no brakes...only in a pinch, (I've done worse than that though) however, even though it was in a much smaller and lighter car, the rear brakes just don't do that much work.
That is why new cars will go 100,000 miles and not need anything done to the back brakes. It is getting to be common place for the brake cylinders to burst before the shoes are actually worn. I have seen this on my wife's drum (rear) mid size SUV, and about 25 cars, light trucks, and even heavy duty (F-500) trucks in the shop I been workin in for the past 2 weeks.
Plus, as stated, there is no cheep way to do this, onless you are real good, or dam lucky. So the dollar verses performance comes up kind of short IMO.
I would be interested in seeing the 60 to 0 times on one of these trucks with disk/drum, and then the improvement after disk/disk.
100 bucks says it is not very much of an improvement.
I will stand my my opinion that it is not worth the cash.
But, again, this is just my opinion

[ChevyMonkey]

thanks for the input guys, as for the engine i have right now a stock 350 with a busted quadra jet, and that pretty much it, everything else is stock and old, i figure that i will put the edlebrock performer on for the intake and some new carb prolly a 650cfm edlebrock electric choke, as for new cam i have no idea what to get, so any and all opinions r welcome on that, might get new headers not sure yet, new exhaust for sure, dunno what yet, kinda leaning toward just glass packs. then its on to the trans (th350) im gona see how much it will cost to get it rebulit and all the stuff replaced with new stuff, and a new kickdown harness wire or whatever it is.

[junkyardjohn]

LONGHORNMAIL - HI ANDY - I THINK YOU'VE GOT THE WRONG IDEA ABOUT 4 WHEEL DISCS. THEY DON'T MAKE YOU GO FASTER, JUST STOP QUICKER. (AN AWFUL IMPORTANT FEATURE WHEN TRAVELING AT A HIGH RATE OF SPEED). THE REASON REAR DRUMS LAST, LIKE THEY DO, HAS TO DO WITH THE PORPORTIONING VALVE. ABOUT 70% OF THE FLUID PRESSURE GOES TO THE FRONT DISCS, WHILE THE REMAINING 30% GOES TO THE REAR DRUMS. SO THE FRONT DISCS ARE DOING 70% OF THE STOPPING. NOT SO WITH FOUR WHEEL DISCS. YOU'D BE AMAZED AT TRYING A PANIC TYPE STOP WITH 4 WHEEL DISCS & AN AJUSTABLE PROP. VALVE ADJUSTED TO A 52% FRONT - 48% REAR PRESSURE. I PULLED A FORD 9" (WI DISCS) OUT OF A 76 LINCOLN MARK 4 FOR LESS THAN $100 AT ONE OF THE LOCAL BONE YARDS. (IT'S 5 ON 5 BOLT PATTERN) NO GRAN PREE RACING FOR ME, I JUST WANNA STOP. LOL

[colohusker]

A case in point, my commuting car is a 90 Corrolla with drums on the back. Just hit 200K on it, and have yet to replace the shoes in it. I check them every 3 months when I'm checking the front discs, and even though they are getting a little thin, they are still okay. The discs on the front on the other hand, I've had to replace pads about every 45 - 50K, and rotors once. The hotrods I had in high school were the same way about the wear pattern, seemed like I was always replacing front pads or shoes, and hardly ever replaced the rear shoes.

About the only reason I would consider going discs on the back would be running road tracks or rallys where you get a big handling boost by having all 4 wheels brake evenly.

Who wants to stop? Well, besides the people in front of my truck...

[ebfabman]

Hey Low69CST versailles rear ends have a 5x4.5 inch bolt parttern, the cad seville has a 5x4.75 inch bolt pattern, but the rear calipers are the ones used in most of the kits.

[Shane]

hey ebfabman....the '77-'79 Cadillac Seville rotors are 5.000 x 5....but can't say on other years.

That is what is on the rear-end in the pic below....no modifications at all to the rotors. Cash and carry at the local auto parts house and slipped right onto the axle.

I did modify the brackets and had to turn the center section and the large O.D. of the axle flange down (about .025-.030)......but the rotors slip right on.

[ebfabman]

yeah you are right, its the later models, I think 80-84 or so sevilles that are 5x4.75. I just took 10 pairs of calipers off of sevilles and the earliest one I think was 81or 82, most were around 84-85, but every caliper is identical.

[Southpa]

The cheapest (and easiest) option for converting your front drums to discs is to go out and find a complete front end off a 71 or 72 truck. I'm only suggesting this if the rest of your current front end needs work, ie. ball joints, tie-rod ends etc. and a suitable donor is available.

I had no choice in the matter as my x-member brackets were really, really bad. Thats definitely the only option in my case because those brackets are rivetted to the x-member. A front-end guy took the truck for a spin and said, "This is the ONLY kind of truck I know of that you can still drive in this condition."

Rear discs? I wouldn't mind, but look at the master cylinder on a front disc truck. The larger well is for the discs, smaller for the rear drums. Thats about the same proportion of braking power distributed to front and rear. But I certainly wouldn't empty my bank account for rear discs.

[Shane]

yeah....i think the calipers are the same......and expensive too!

If you got 10 pair, you found a gold mine! I looked for a couple of weeks before I found a Seville with calipers still attached. The street rodders found all the others.....LOL!

For the others reading this......when you go to buy your new or rebuilt calipers, keep all the E-brake linkage off your cores...the new ones dont come with them!

Hope this helps.......

[68gmcjon]

as to the engine i have a 402 w/ edel. performer rpm intake with a 750 cfm holley carb. i love em'. Has for the cam i would go with crane cams don't have one but have heard good things about them.

[imdarren]

Shane,
What did you have to do / modify on those Cadillac Seville brackets to get proper fit on the rear end?
And was it difficult?
Also. About what would the parts off the Cadillac Seville cost (roughly) from the average bone yard?
Looks sweet! You did good!
Darren

[Shane]

I opened up the backing plate center hole on a Bridgeport mill, with a boring head. Once i had the center hole bored out, I re-drilled the mounting holes. Most machine shops should be able to do this for you. You need to make them a sketch with the dimensions of the bored hole and the position of the new drilled holes. Better yet, take your old backing plate (drum brake baking plates) with you and tell them to use that as a reference for your modifications. You will also have to have the axles turned to fit the rotors too. I suggest buying new rotors and take them to the machine shop, so the machinist has something to use as a reference. If you cant find anyone to do this for you, email me, i may be able to work something out for you.

I cut the "pie-shaped" section with a "Zizz" wheel, or however ya spell it. I made sure that i had at least 2 bolts opposite the rotation of the wheel/tire. This is to counter act the torque placed on the backing plate when the brakes are appplied. With the Caddy setup, the passenger side caliper is mounted on the the rear of the axle and the drivers side caliper is mounted on the front of the axle. On the passenger side, i cut it so that the top of the backing plate has two bolts in it and the bottom has one, where as the drivers side, the plate has the two bolts on the bottom and only one bolt on the top.

I got the idea of only using 3 bolts and mounting on the back of the flange from the aftermarket kits you can buy for the Chevy 12 bolt rear end. They use Caddy calipers and Caddy rotors, which you can buy at your local parts place. What your paying the extra money for is the brackets that they have designed and made. Their brackets are 2 piece and only use 3 of the 4 bolts on the axle flange.

I had to mount the backing plate on the back side of the flange in order to get the correct spacing. With the bracket mounted on the front of the flange, the caliper would not line up with the rotor and the backing plate. Once placing it on the back of the flange, it lined up perfectly.

Salvage Yard Prices

2 - 1978 Cadillac Seville rear calipers - $25.00 - pull the e-brake linkage and then use as "cores"

2 - 1978 Cadillac Seville backing plates/caliper brackets - I found these through another board member because my local salvage yard would not sell me just the backing plates - I had to buy the entire rear-end if I wanted them......$300.....No Thanks!

New Part Prices

2 - new 1978 Cadillace Seville rear rotors - $59.99 each at local parts house (AutoZone - Pep Boys - NAPA - etc...)

2 - new 1978 Cadillac Seville rear calipers - $79.50 each, after turning in cores - they will really stick it to ya on the core charges, so make sure you find some good ones from the salvage yard - you also don't want to try and rebuild them...they are a real pain in the rear with the e-brake mechanism

Hope this helps.....

[Low69CST]

Somebody back me up on this. I know there was a lincoln rear end with 5 on 5 and disc brakes. I talked aobut it with too many people and it has been discussed on this board.

[ebfabman]

All big linc's are 5x5. Its just the versailles that are 5x4.5

[ebfabman]

That includes the big linc's with rear disc brakes. I used many linc rear ends for race car rears, we would take two short side axels, shorten the long side housing tube and make a narrow nine inch disc brake rear out of them. Left a lot of nine inch rear ends in the salvage yards with no short side axels in them, musta pissed a lot of people off....LOL

[chevyman 68 C/10]

My 99 GMC stops effertlessly and on a dime, if that is silly, then silly is for me.
I located a Mercury rear with 5 on 5 discs and made a deal on it, just need to locate posi and the right gears.Does anyone know what I should be looking at to locate a posi 9 bolt (pick- up car or what)

[PanelDeland]

I don't think disc rears are a waste.Almost all new cars/pick-ups are being equipted with them.This means eventually every other ride on the road is going to have that much better braking than you.If it happens to be one of those idiots who darts over and slams on his/her brakes they are going to be stopping quicker and they know they are doing it,you have to react.
As for engine combinations you should look at what you have before modifying it.Run a compression test,check for leaks and determine whether you can put the load the new parts will on your rings and gaskets ect.If the engine is weak you will not gain much by installing a cam.
You can always use your intake headers and external parts like distributors on a rebuilt engine later.
I guess what I am basicaly saying is to think thru what you want to do and make an overall plan.You will spend less money and have better results without having to go back and do something over because it won't work with the rest of your combo.