Big Brakes for my 1987 Silverado in the works

[modular93fox]

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 camaro... 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. 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.

https://static1.pt-content.com/images/noimg.gif

https://static1.pt-content.com/images/pt/2010/03/img0112o-1.jpg

Sorry for the large picture, but by the looks of the cars on this site, I'm sure most of you guys have atleast a 21" monitor ...lol.
clint

[joeelutz]

I'm interested in your setup as I would like to put disc ont he rear of the 67 C10 I'm working on. What lug pattern is the Dodge? Did you redrill the rotors? This may be a good application for the D52 Wilwood calipers. That's what I'm using on the front because they mount like stock calieprs.

As far as Prop valve goes, I would just use an adjustable valve. I can help you out if you want to use Wilwood stuff.

[modular93fox]

The Dodge's are 5x5.5... I just made a template and redrilled them myself. I dont have anything against using Wilwood calipers, they are great for people who can afford them, but pulling parts off at the bone yard is more my speed. Plus the availability on the parts shelf is always there. Thats the main reason I'm doing this conversion. I would have loved to drop 700ish on their slick bolt on rear brake kit but I didnt see myself doing that.
clint

[novaderrik]

what size are those rotors?
i only ask because the 94-96 Caprice/Impala SS/Roadmaster has 12" rotors with the same 5X5 wheel bolt pattern and center hub diameter as your truck, internal drum style parking brake, and PBR calipers. i think maybe the mounting flange on the rear end might have a different mounting pattern and offset to the axle flange, but that's easy to overcome with a little work.

[modular93fox]

Theres a guy on the http://67-72chevytrucks.com forum that sells the Impala SS brackets for 70 bucks, no option for ebrake at this time it looks like. heres the link to the page.

http://www.67-72chevytrucks.com/vboard/showthread.php?p=3259777#post3259777

The Dodge rotors a bit bigger measuring in at 13.8". A little massive, but when your putting on disc brakes, mine as well get something large :) just need to proporition it. In the end, I plan on using the front brakes off the Dodge too and just get the master and prop valve.
clint

[modular93fox]

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

https://static1.pt-content.com/images/pt/2010/04/img0119fz-1.jpg

[modular93fox]

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... 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.

comments?

heres what I've come up with so far..
https://static1.pt-content.com/images/noimg.gif

[modular93fox]

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

https://static1.pt-content.com/images/noimg.gif

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

[modular93fox]

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

[joeelutz]

I say if the rear locks up too soon, then add an adjustable prop valve. If not, then don't.

[modular93fox]

As it is,all OE on the PV, the fronts lock up before the rears. Overall the truck stops great compared to before, but before i only had 2 wheel brakes... So I probally will buy a adjustable PV valve and gut the stocker and go that route.

as it sits now:

https://static1.pt-content.com/images/pt/2010/04/dsc0809i-1.jpg

[mone]

So how did you even come up with idea to use the Dodge stuff?And how does it stop?Im very interested

[modular93fox]

idea probally came from pro-touring.net and everyone (with camaros) doing rear disc brake swaps.. and now that I had nice wheels... I wanted to get rid of the drum. A friend of mine in florida tried McGaughys 13" rear kit which consists of a C-5 front rotor, re drilled ofcourse + some 70 model cadillac caliper.... old school stuff. The guy said the kit required too much modification even though he bought it for his application. I beleive the ID of the front rotor wasnt big enough to fit over the axle pad. So, I noticed my friends dodge ram had a nice sized rear brake and was like, hey its 5 lug.
I was going to use all 99+ silverado rear brakes, but you cant lay a 5x5 pattern over a 6x5 pattern without welding some holes shut and so on... nonsence... :) sence then, I ran with it like a kid with sisors :) Stops real good, but I ran about a month and a half with no rear brakes so I noticed a huge improvement.. maybe next weekend I will hook up HPtuners to my truck and log a 60 - 0, and measure the distance too. I will take the advice given to me from other members here about gutting the p-valve and plumbing a adjustable on for the rear to get the most out of the rear brakes. Im not done with the rear yet, I still need to make a "main axle flange bracket" to mount the ebrake stuff too. I really want to find a spare rear end so I can do some mock up instead of tearing into my daily driver.
clint