rear disc brakes on 3/4 ton and posi?

[sleepertruck72]

Youre making excellent progress ! Im gonna start replenishing my secret parts money stash for this upgrade

[sdwolff98]

Hey sleeper how many bolts on the axle backing plate do you have? 4 or 7?

Sean
Posted via Mobile Device

[sleepertruck72]

Originally Posted by sdwolff98

Hey sleeper how many bolts on the axle backing plate do you have? 4 or 7?

Sean
Posted via Mobile Device

Sean,
7 bolts...


Jorge

[sdwolff98]

Sleeper
EXCELLENT !!!!!!!! Gives me an idea of year ranges now yipeeee.

Thx
Sean
Posted via Mobile Device

[sdwolff98]

Hey Guys,
Need a bit of reasearch when yall have time and are up under yalls trucks? I am trying to find out in what year they started the 7 bolt backing plates for the 3/4 and 1 ton trucks? I know they had them on the 64 years but I need to know about older ones also are they chevy or gmc. That way I can put together a year range for the kits for posting in the classifieds section eventually. My Wife and I are house hunting right now so might be a few months before I can get a few made up or in nothing else make some additional adapter plates for sale.
Most of the parts I was able to get through o reilly's auto parts but there are some that can only be had through a chevy dealer luckily they aren't hideously expensive.
so far we have 1964 - 1972 3/4 tons that have these. Also do the 1 tons have the same plates? Another thing is on trucks newer that 72 are they 4 bolt plates or 7 bolt plates? If they are 4 bolt plates I will need to get victims when I have a shop setup to design prototype plates for them and go through the whole lazy machinist stage again lol. I got the bill from him lol 2286$ but that included my screwup in the first place lol.


Dealer only parts:
Backing plates: roughly 36-65$ a piece depending on dealer and these fit both sides there is no l or r side plates
e brake cables I am still working on I have the 3/4 ex cab ones in my hands atm that I am working with but all the cables run about 44$ each side
e brake actuator levers 15$ each at dealer

thanks guys for the encouragement and support!
Sean

[sleepertruck72]

I will be ready hopefully in a few months for this upgrade, Good luck with the house hunting

[sdwolff98]

working on the brake hose and e brake lines at the moment. have to go to the chey house for something called an wqualizer. apparently the stadard/ext/crew all use the same passenger side brake cable which is shorter thatn the driver side and have the equalizer on the cable somewhere along. So going to order or grab that monday and find out what it is used for. Cnc shop has one of the adapter plates and am now waiting on workd as to how much they want per set and will get back with yall on that as soon as they talk to me!
So far with exception of the plates parts have run: 892$ with a couple of core charges in that number. so once I have the price for the plates I can work up a reasonable price for a kit for this setup!
Sean

[sdwolff98]

Ok ghuys plate estimate still waiting for it at the moment so on to other things. I am working on the ebrake cable setup as we speak. I have a set from the 2008 truck in hand and have them kmounted to the brackets trying to figure out which is gonna be easiest to get em working at this time. looking at a modified 67-68 setup right now. Willk know more as I get things further into it. Waiting on a fewn small parts from chevy dealer now lol.

Sean

[sdwolff98]

Hey Guys,
update time, just about have the e brake cable setup figured out waiting for machinist to cut me a slot to test it out with my existing emergency brake transmission bracket in my truck. the brakes have fit together quite well. Have to chenge the metal line to a metric fitting to match the 2008 components. So will have everythign assembled and together late next week and will have plenty of photos. Going to be a while before i can get some braking tests done on the setup but it is coming

sean

[sdwolff98]

Got the emergency brake adapter ready for the newer e brake cables. I designed something using the newer equalizer which will fit to my existin e brake setup. If yall have the cables going all around the underside of your truck we will have to figure something out for there. Should not be too hard tho since the cables on the newer chevy are similar in size to the older ones.

check it out!

Sean

[68 TT]

Originally Posted by sdwolff98

...so far we have 1964 - 1972 3/4 tons that have these. Also do the 1 tons have the same plates? Another thing is on trucks newer that 72 are they 4 bolt plates or 7 bolt plates?

The 73-up 3/4-tons have a 4-bolt backing plate but are a different rear end entirely. It is the GM 14-bolt that is still in use today.

The older drum brake versions are easy to convert to 12" x 1.25" rear disc with some easy to come by simple and inexpensive caliper mount brackets, a set of square body K20 rotors and some 78 Eldorado brake calipers with integral e-brake mechanisms. Many people do it with K20 front calipers and run a driveshaft mounted e-brake setup because the Eldorado calipers are rate and troublesome.

I have one going into my 69 K10 in place of the truck 12-bolt.

The later ones already have disc on them. You may be using the stock 14-bolt disc brake parts in your conversion for the HO52. I don't know if they changed the backing plate mount design on the stock disc brake applications or not so it might be an opportunity to make conversion parts to use the bigger brakes on the older 14-bolts.

[sdwolff98]

Well Ok guys have been off n on busy with this project and things are starting to come together. I finished up the brake cable mounts and attached them to my transmission bracket e brake cable lever.. Here are some photos.... NExt project getting the frame front to rear line in place and then make a set of metal lines for the axle plus mounting tabs for the hoses. I have still to secured the back brake cables to the frame. But so far everything is working great. The 16 rims I have on my truck are old wagon wheels and they clear the calipers and rotors no porblems.. I routed the cables over the frame brace and seems to be working good just need to come up with come clamp style mounts to hold em down and out of the way of the driveshaft.

Looking at possible building myself a home cnc unit here in near future to cut down costs on the brake plates. Aggravating issues is the cnc shops I have talked to don't seem to want my business or it is astronomical the prices they asked grrrrrr.....

Sean

[jbclassix]

subscribing... scheming...

[sdwolff98]

Well guys havent done alot more yet on the brakes but fixing to get back to that here very soon. I got the front to rear frame line chenged over to a metric tip to install the newer t hose on the truck just have not had time to get it into the truck to check the fitment to the axle. I am fixing to take one of the plates off and run to as many cnc machine shops to see about pricing for more with the locator bushings etc. If anyone is a machinist or works at a cnc mill let me know!!!!!!!!!!!!! I would be willing to send one of the plates to your for duplication and we can get this going for the guys here that are interested in this setup. The new plates my machinist made for me are identical twins so making the one plate fits both sides of the truck. one side is upside down from the other to get it oriented right for the brake cables and etc.

Sean

[sdwolff98]

Well some more updates the brackets I showed you in last post worked great to hold the brake hoses in place. Just trying to find the right clips for them now lol. I am using off the shelf oreillys metal lines with metric fittings for the axle lines so far the driver side one is fitting nicely and snugly in the fittings. Will get some pics in the next week or so and post em up!


Sean

[sdwolff98]

rear brake line pictures as I said I would post. Just need passenger line installed with brake bolts and copper washers then find the clips I need and done deal. Then get the front rotors turned new studs and fill er up and bleed the system to check for leaks all down the setups. then get the ebrake handle in the truck and hooks up the cab to frame cables and see if it needs adjusting at all!!!!

Seam

[sleepertruck72]

Awesome progress

[sdwolff98]

haven't had much time to tinker with this project but will be getting back after it very soon. axle got damaged so having to replace the housing. while its off going to take the plates by a fellow cad cam programmer and have him set me up some specs to take to cnc shops for both aluminum and steel adapter sets. shuld with any luck satan willing and murphy ignoring me start testing these out this coming fall and give yall an up date on how they perform

Sean Wolff