Decoding Build Sheet "FRONT BRAKES" help

Getting a little closer to finishing the first ever Build Sheet decoder. Starting out with 1970 only because of all the code changes and sheet design changes each year, but the other years should be fairly easy to add once the framework is there. It's the only way to make it work to the highest level of accuracy. Once done, this decoder will be free for anyone that wants to use it.

The code that we're cracking now is the line #4 on the far right of the page called "FRONT BRAKE". This "Front Brake" might be another one of those codes that does not use the last digits of the part numbers. Can you guys help me crack the code? Here's where I'm at now (this is not confirmed so don't write it down in stone yet)... still working through it.

Here are the Front Brake codes I have, can everyone please check to see if you have anything different on your 1970 E-Body build sheet? 1970 only at this time. (I'll do 71, 72 and so on later)

I think the key to decoding it is a correlation to the between the Front Brake code and the Line 6 (B) H/DUTY OR DISC.

LINE 4
"FRONT Brake"
22 = Should have a blank spot in H/DUTY OR DISC?
23 = Should have B11 in H/DUTY OR DISC?
29 = Should have B41 in H/DUTY OR DISC?
59 = Should have B42 in H/DUTY OR DISC?


The factory working looking at the build sheet and building a K-Member would also most likely be adding the Sway Bar, Shocks and Control Arms and Front Brakes? And all of these items are right next to each other on the build sheet too. So I'm thinking that "Front Brake" code box could be used for steering knuckle, backing plate, brake lines or ??? I have not been able to find the four codes above in the brake section of the parts catalog. The only thing that I can find is this:

2880529 = 10 x 2 1/2 Front Brakes. But that doesn't work with code 29 because code B41 is front disc brakes. So scratch that. And nothing else really lines up. :thinking:

So I moved to the Suspension part of the part catalog. Somewhere on a build sheet the worker needs to know what Steering Knuckle to use for the front brakes. So I'm thinking that it might be the Spindles (Steering Knuckle)? But would E-Bodies have 4 different steering knuckles? I think there would just be 2, right? Disc brake and drum brake.

So what could have to do with the front brakes for E-Bodies and they need 4 different parts? Could it be the front brake lines and or proportioning valves? I think the key in this puzzle is what is the difference in the front brake between codes B41 (Front Disc w/ Standard 10" rear drums) and B42 (Front Disc w/ HD 11" rear drums)?


Some thoughts that people have had so far:

Build Sheet Decoder Help "Front Brake"

In my gut I think the "Front Brake" is going to end being a code for a pre-assembled front brake component with the brake lines attached or something. So it might not be something in the Parts Catalog?

Just thought of something. Since it would be a Right and Left situation, it almost has to be a code for both (a group of parts or assembly). So that's why I'm not finding the code in the Parts Catalog.

Now I just need to figure out what group of parts it represents.

What parts in the front end brakes / wheel area would be different from standard that they would need to have a different assembly?

B11 = is what in the front?
B41 = is what in the front?
B42 = is what in the front?

LINE 4
"FRONT Brake"
22 = Should have a blank spot in H/DUTY OR DISC? = 10x2-1/2" drum assemblies
23 = Should have B11 in H/DUTY OR DISC? = 11x3.0" drum assemblies
29 = Should have B41 in H/DUTY OR DISC? = disc brake assemblies
59 = Should have B42 in H/DUTY OR DISC? = TRANS AM disc brake assemblies

figuring what was included in each assembly: everything between both control arms - more or less? might be more difficult

what is the difference in original components of "disc brake" VS. "TRANS AM disc brake"?

left VS. right might have been as simple as the assemblies being marked xxxxx22L & xxxxx22R on the assembly line?

The 59's I have are on J code T/A cars? ummm....

Could you get a non T/A E-Body in 1970 with B42 (Disc Brakes w/ 11" rears?)

Dan I think you're on to it!!!! We might have cracked the code, but now what does it mean? Why would they need a different front brake code for those four options?

Brake lines / connectors?

Getting lots of help from a few places / people and so far everything is holding up. Lets assume it a sub-assembly and test this theory.

LINE 4 FRONT BRAKES
22 = 10" x 2.5" Drum Brakes assembly (w/ 10" x 2.5" Rear drums)

23 = 11" x 3" Drum Brakes assembly (w/ 11" x 3" Rear Drums)

29 = Front Disc Brakes assembly (w/ 10" rear Drums)

59 = Front Disc Brake assembly (w/ 11" rear Drums - TA & AAR)

it is the last 2-digits of the 7-digit assembly part number for the front brakes

the number includes everything to hang the brake assembly between the control arms:
from the dust cap, drum or rotor, backing plate or dust shield, brake hose, lower ball joint

the rear axle assembly takes care of the rear brakes, there must be something in an OE "TRANS AM" front assembly that is different than other disc brake cars,

spindle (X-rayed or treatment?)
brake pads?

some part that is different but does not affect the interchangeability?

Cody what exactly are you looking for. How the plant assembled the complete front end or how the codes reflect to the build. There are also alternate build related information sheets or tags that were used in various plants. So you would like to narrow it down to the 1970 E Body build but there were two plants building E Bodies and could of run different to assembly them.

I have not looked at any schematic on how either E body plant was set up. Likely back in the day they had a sub assembly line for such a build. It would start with the K Frame at the first work station and then a predetermined build after that. The work station would either read off a Sheet for that Specific assembly of the front end or have the information of the build at each workers work station. It also could have other sub-assembly jobs that feed this line. This is were the Sequence number drives the build. Not the VIN. Once the front end is complete I would think it would make its way over to the Main line to be added to the Sequence of build. Not sure how this would be done or if the front suspension build is the main build.

Yes, hemicar1971 I'm looking to find out how the codes reflected what was installed on the cars.

Don't TA/AARs use a different booster than a 340 4BBL car? That would tell me 59 means install this special booster.

You might have nailed it. They did it for a reason, so that might be it?

if it was to include the booster - then there would be additional numbers for HEMI power drum & HEMI power disc brakes

That seems logical.

[quote}Don't TA/AARs use a different booster than a 340 4BBL car? That would tell me 59 means install this special booster.[/quote]

YES, different part number,
looks identical from the outside. My guess is the difference was the booster nipple used on the T/A AAR. I dont see anywhere there is any other differences unless its internal on the diaphram