13.8 Rear Disc Conversion for the truck 10-bolt in the works

[87chevy.com]

I dont visit here much, but so the words out there, I will be posting these bracket for sale in the for sale section when I have some.

Finally made some real progress on doing something about the rear disc conversion. Its really a conversion becuase the donor brakes came off of a 2002+ Dodge Ram 1500. Story behind my choice is pretty short. They had all of my requirements, large, internal parking brake, and 5 lug. Another reason why I chose the Dodge is because the parking brake components are 1/2 the price of the Camaros (100ish compared to the 50, plus they are Bigger and Wider!)... not like you go through them or anything, but when the time arrises kinda deal.

To start off, I picked up all of the rear brakes complete less than the parking brake cables for a steal of a deal! I even got the caliper mounting bracket which unfortunatly just couldnt be modified to work. Well off to desiging my own brackets. Took a while figuring out how exactly I was going to do it but this is that I've come up with. I printed a copy of the brackets and transfered them to sheetmetal and made a set of brackets and it works.. spacing wise that is. As far as the rotor, I just made a template in AutoCad and drilled them myself. Spot on! I still have not done the math on which master cylinder I should use or how to mod the prop valve. I plan to do that soon though as the brackets should be arriving in about a week. I didnt choose the Impala SS brake setup simply becuase its only 12" rotor. My logic is if I'm going to do all of this work, mine as well get something large and common (common in the wrecking yard... Impala SS' are not). I have not attempted at making the parking brake work yet becuase I want to make sure the caliper bracketry is spot on, so far it is. It can be an option whether or not you want it....
check out the pic's.





Sorry for the large picture, but I dont have CS2 loaded on this computer.
clint

[pcmcobra]

clint,
looks good!

[STOCKISH]

Looks great man. Thanks for all your hard work, that should help alot of people out. Dont forget to become a supporting member before trying to sell these brackets. Cant wait to see the finished product.

[87chevy.com]

Originally Posted by 1972SuperCheyenne

Dont forget to become a supporting member before trying to sell these brackets. Cant wait to see the finished product.

When the product is out, I'll pm you on the how to..

hey John, hows the truck, hows the wife and kids

[Stitch]

does this have the dodge bolt pattern or does it have the chevy bolt pattern...if I'm correct, they are different

[87chevy.com]

OE Dodge rotors are 5x5.5. When the "kit" is complete with or without p-brake, it will have a template to drill your new pattern. I just made a template in autocad and drilled the new holes myself using a DeWalt drill and a 17/32 drill bit. 1/2" wouldnt clear the new longer studs. I needed longer studs due to the wheel spacer I am running. I like the front tire to fender spacing, and the rear is just sucked in too much. With the 1.5" spacer in the rear, it lines up perfectly with the front... mmmmm.
clint

[staggerd86c-10]

so what do you have in the front cause i think the rotors in the front are only 11" or so.

[87chevy.com]

haha, ya, once I have both rear brakes in operation, I'm going to turn the front rotors into hubs, then mount some front Dodge Ram 1500 rotors / calipers so all I have to purchase to make the brake system balanced and correct would be the dodge's master and prop valve. Since ABS is not standard on those trucks, it will fit right at home here. Well thats the plan anyway. For now I just want to have the rears working again. Its been like 2 weeks since I had rear brakes...
clint

[N2TRUX]

I like the 13" rotor idea. Not really sure about the Dodge calipers though. Seems they had some issues with not releasing properly on certain year models. You might want to research that before you commit.

[87chevy.com]

couldnt find anything when I did a quick search.. il look a little harder next time.. you wouldnt happen to have any links would ya?

[N2TRUX]

Nothing current. I had an 04 Quad cab and did some research before I bought it. I remember that the rear calipers were problematic, and I "think" they may have had a service bulletin on them.

What about setting them up for the Camaro calipers with built on E-brake?

[87chevy.com]

thanks, just checked alldata.. should be called somedata... didnt show anything bulitins other than brake shudder due to warped rotors... As far as the LT-1 style calipers, Im unsure of the rotor thickness but if its close to the dodges (which I dont know off hand.. but I wanna say close to .80") then it could work. Would have to check the rotors contact are to see if its close to the Dodge's so it would be using the area effeciently and what have you. But if it came down to it, if say I were to get a LT-1 rotor and caliper free, I would/could whip up some bracketry. Those rotors are close to 12" so it would match the fronts a little better and quite possibly be able to run 15" wheels. With the 17" aftermarkets I have, theres not a lot of extra room .
Originally I was just going to do the LS-1 rear brakes but those corvette parking brake setup is like 140ish from gmparts direct.... on top of that the e-brake portion is only like .5" wide...if you had to use it for any reason other than parking you would destroy that and the "refills" are still 75$ ish... plus no wrecking yard will seperate any rear corvette components... or alteast the ones I've gone to.

[N2TRUX]

Here's my theory on this. As you know, there are a few suppliers that offer similar brackets for Impala SS rotors which is nice because they don't have to be drilled. Does anyone make a 13" rotor for that application? Even if you had to pay a bit more for the rotor, you would save time/money if you didn't have to drill. If that's not an option, then these might be the next best choice.

The other thing to consider is what will match with the front? My thoughts are if your going to put this together as a kit, you should look at making it an affordable matching set. No one that I know of offers a "parts shelf" kit for 13" rotors for the 73-87's.

[87chevy.com]

as far as the rotor drilling, its really wasnt a real big deal. just put some sticky goo on the face of the rotor laid the templated down on the rotor, turned it upside down and moved it untill i could see all of the markings and untill they were centered. Simply got a punch and marked the holes. Even if say a lug hole was a tad off, the axle register is the same as the dodge rotor so its hubcentric.
I dont think there are any factory 5x5 with larger than 12" disc brakes.
As far as the fronts, my plan is to make a setup like McGaughys front big brake kit for our trucks... basically their stock drop spindle with the ears chopped off and 2 holes tapped for an adapter bracket. then a 99+ chevy caliper gets mounted to that. The rotor looks identical to a corvette, but it only has one pattern the face (could be a stock photo, but Im not sure).

[87chevy.com]

talked to the cutter, and they said the brackets will ship tomarrrow... cant wait to see them (although I know what to expect). I've done so many 3d modeling and this is the first project to come to life.. anyway..
clint

[aggie91]

I got to watch this one.

[87chevy.com]

man I am going to sleep good tonight! I love it when a plan comes together even if its not the original plan. Well the brackets came in finally, well actually 2 days ago, work just didnt let me know untill last night... agh. Well I was itching to crawl under my truck and play around after work so when work was finally over with, I go for my wheel lock and its at home.. dang. Anyway, with the tools I have at work, I was able to dismount eveything with the wheel on the truck, yes!
My friends could describe me as impatient and I am, so instead of waiting another day, and poping the diff cover off and mocking things up again, I just decided to notch the axle flange bracket similar to what others have done - so it mounts with 3 bolts.. man my measurements was on the money! Originaly the axle flange bracket would mount as the original backing plate was, but after I mounted it up, there would be no way to mount the parking brake stuff... not exactly what I wanted to see. So, I slap it on the back side and fit perfectly with no beveling b/c of the flange weld - sweet.
So right now, all I'm lacking is the spacer which I believe I figured out today whats going to be the solution to that.. and man I was happy! Tomarrow Im going to place a second order for the other side with a cosmetic refinement! Right now one side is 100% solid!
Once I install the other side, I will start working on the parking brake side of things because when for some reason I only pulled the backing plate off of one side...
without further adu picture of the brackets in 3/8 form...

clint

[love my 72]

Originally Posted by 87chevy.com

2002+ Dodge Ram 1500. Story behind my choice is pretty short. They had all of my requirements, large, internal parking brake, and 5 lug.

Hey 87 Chevy, great Idea since some of these truck came with 20" factory wheels and Impalas came with 17" wheels.... About the 5 lug thing, ....Not the same bolt pattern so not that big of a deal since the rotor had to be re drilled for the 5x5 bolt pattern

Originally Posted by 87chevy.com

I didnt choose the Impala SS brake setup simply becuase its only 12" rotor. My logic is if I'm going to do all of this work, mine as well get something large and common (common in the wrecking yard... Impala SS' are not).

I personally would not trust any brake components from the wreaking yard, hints its ended up in the wreaking yard for a reason! Impalas might not be so common in wreaking yards but caprice's are a dime a dozen, i happen to be in favor of putting GM parts on my truck.. but I'm just kind of an ass that way!

Props to you on the ingenuity, at some point common sence comes before brand loyalty and i think if you rebuild you calipers prior to bolting them on then you are working on a great set up! Best of luck bro im sure you will be pulling it off really soon!

[87chevy.com]

yeah, the redrilling part is not difficult at all unless you dont have a drill and drill bits.. as far as brand loyal... if gm offered trucks in 5lug with disc brakes and parking brake option, i would have jumped on that. Originally I was just going to use ls1 or corvette stuff for the rear, but the ebrake stuff is pricey new and you wont find a corvette to pillage at the salvage yard. Thats why I went with the dodge running gear. Only concern about the corvette rear brakes is the inner hat area for the axle flange to mate to. McGaughys uses the front rotors for the rear kit and you have to machine the axle and rotor.. not an option for me and my truck. I dont have any specs on the rear setup but if someone wants to donate a set of ls1/corvette rotors and calipers, I will make you a set of brackets in exhange, but other than ... anyway dodge rams have pretty stout brakes.. a friend has a 1500 swb and its a bare bones truck, no abs... stops on a dime.

[87chevy.com]

Made some more progress this weekend. Went to the wrecking yard and got a front rotor and caliper off of a dodge and got home to find the plastic piston was broken.. no biggie, I'm sure they will let me exhange it. The rebuild kits dont come with a hard part like that.. anywhoo I drilled the new pattern on the front rotor and slid it over the front brakes (rotor installed backwards) just to see how it fits the factory hubs register. Fits perfectly!
I choped off the ears of the stock spindle, drilled and tapped the dust shields like another member has done. Im lacking a donor stock rotor (to turn into a hub), and I'm unsure how I want to go about this. The pick-n-pull will probally charge 20 bucks plus a core fee, while autozone has a good, better and best front rotor that starts at low $30, then $40 and $50.. Im not sure what makes them good better and best, but I will be chopping the rotor portion off anyway to make it a hub. The thickness of the dodge rotor pad is .30".. not too bad unless your running a wicked negitave offset. My 8" wide wheels with 0 offset (265/50 or 60) rubbed the outer fender only once (going to fast out of a sligtly steep drive) and cut the tire due to non rolled fenders. Since then, not a peep.. I think I might go for the autozone cheap rotor, and grab a set of bearings from the junk yard (for mock up only) and start there.
Im pretty sure I got the parking brake design worked out... but I ran out of time to take more measurements. Essentially there will be a 1/2 plate on the outside flange (where the stock backing plate was, and the factory dust shield/e-brake hardware will mount to that. It looks like the original flange bracket will have more metal on the bottom to accomidate a pair of 1/2 bolts that will act as the base/pivot for the brake pad shoes, and there will be a spacer to support the 2 bolts. Dodge sells the backing plate/bracket and all ebrake shoes as a "kit" for around 125$. Have not priced the cables, but they look like they would require almost no mods to the factory cable (cab to under bed).
Making slow but solid progress..
clint

[87chevy.com]

well I finally made some good progress this weekend on getting the e-brake function to work. I plotted all of the necessary points to attach the dust shield that holds the ebrake shoes to a secondary bracket that attaches to the axle flange (outboard side). The caliper brackets mount on the inboard side. In the attached photo, the black piece is the axle tube itself. I changed the "main caliper adapter bracket" to accomidate the e-brake pivot point.

...if you can imagine the base (where the ebrake stuff pivots) of the factory cast piece, similar to the picture below, its solid cast material, with 1 notch on each side, say 1/2 way down so the shoe fits in that notch and pivots... thats what im trying to mimic. so thats what the spacer below the axle tube is. I think I need to stare at it longer to get some ideas on how to make it work... without any crazy expensive machining process'.
any ideas would be welcome Original idea was to have 2 1/2 bolts be the pivot and have the spacer there to give it ridgitiy.. but I need to stare at it
heres the setup with the e-brake adapter plate.

clint

edit:
I think if I just change the shape of the e-brake pivot spacer. Instead of trying to mimic the notch in the factory pivot, the entire spacer will be the shape of the notch, essentially the shape of a foot ball... I will just bring the 2 1/2 holes closer in, re-draw the pivot spacer and make those holes threaded. This away no fancy machine work needed... and its not like the shoes move in/out.

[87chevy.com]

ah, today was a good day.. not because of work, but becuase the mail man an ups droped off both of my packages today



Got the spacer I needed, and the other set of brackets for the other side. Also got the hoses for the conversion, right at 30 bucks a hose with banjo bolt, crush washers and mounting bracket, and clip!
Gotta work Saturday, so Sunday I should have everything mounted and working!
clint

[nlped]

Great progress!!! Very interesting

[moneyeater]

Subscribed!
Volker

[87chevy.com]

update:
Finally finished the bending and flaring the hard line tubing. I gravity blead the system for a while then did the buddy system to ensure all the air is out of the rear circuit. Man what a difference going from front brakes only to 4 wheel brakes. B/C of the truck being my daily, I deemed it necessary to bypass the rear brakes untill I was ready to put the discs on.. plus it was more modivation to get done!
As of right now the truck stops great, it has always stoped great with stock disc/drums. I went to our state inspection brake testing area and did the 20mph/25ft and stops within the markers. Even though the front rotors are glazed, they have to be, the fronts will still lock up (start to screatch) when the pedal is suddenly mashed. Im sure that is normal. I just did my homework on piston area percentages.... a few websites show the stock D-52 caliper to be at 2.80square inch piston. Alldata doesnt show anything for the stock chevy caliper, but they do say the Dodge's rear caliper to be at 54mm/2.12". The goal is as close to 70% in the front and 30% in the rear as possible. IF 2.80" for the stock D-52 is correct, then the fronts currently have 56% and the rear has 44%. Im not sure if I want to gut the prop valve or not.... I dont know what the guts of it look like... I dont know if you can mod them besides gutting them and adding an adjustable prop valve. What do you guys think?
clint