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76 Vega to S10 Brake System Upgrade

PostPosted: Sat Mar 03, 2018 6:15 pm
by Mark in INdiana
I'm hoping you guys can help me with some brake system components sizing information.
I have a 76 Vega (Cosworth) that will eventually be a non-tubed, street bruiser with a healthy 383/5 speed/Moser 12 bolt and brake system from a v6 1998-2005 S10 pickup. For now though, I just want to convert the existing 7.5 rear to 1983-92 S10 2WD 5 lug axles and drum brakes. So far so good. For the front 5 lug conversion, can I use the later 98-05 S10 spindles/rotors/calipers with the earlier S10 rear drum brakes and with the existing 76 Vega master cylinder? Or should I just use the 1983-92 S10 2WD front set up also for the initial 5 lug conversion? Here are some component size questions I've not found in my searching that will really help answering these questions;

76 Vega (Cosworth);
1) What is the front rotor diameter and caliper piston diameter?
2) What is the rear drum brake diameter/width and wheel cylinder size?
3) What is the master cylinder bore size?

1983-92 S10 2WD pickup rear drum brakes;
1) What is the drum brake diameter/width and wheel cylinder size?

1998-2005 S10 2WD pickup;
1) What is the front rotor diameter and caliper piston diameter?
2) What is the rear drum brake diameter/width and wheel cylinder size?
3) What is the master cylinder bore size?

I really appreciate your help! Thank you very much!

Mark in INdiana

Re: 76 Vega to S10 Brake System Upgrade

PostPosted: Sun Mar 04, 2018 9:23 am
by cosvega76
Mark,

When you mention 1998-2005 S10, do you mean the single-piston calipers from the pickup, or the dual-piston calipers from the Blazer? Pickups pretty much used the same brake system during their entire run.

If you're going to use the single-piston S10 calipers, you'll need a larger bore master cylinder on the Vega. The S-10 used a 24mm (15/16") master through '97, then a 1" after that, but those trucks usually had a power booster. If you're using manual brakes, an easy solution is to use a '76-later Monza 7/8" master.

Here are your dimensions:

'76 Vega:
1) Front rotor: 9-7/8"; caliper piston: 1.906"
2) Rear brake size: 9-1/2x2"; wheel cylinder: 11/16"
3) Master cylinder: 3/4"

1983-92 S10 2WD pickup:
1) Rear brake size: 9-1/2x2"; wheel cylinder: 3/4"

1998-2005 S10 2WD pickup:
1) Front rotor diameter: 10-1/2"; caliper piston: 2-1/2"
2) Rear brake size: 9-1/2x2"; wheel cylinder (through 2002) 3/4", (2003) 7/8"
3) Master cylinder: 1"


Chuck

Re: 76 Vega to S10 Brake System Upgrade

PostPosted: Sun Mar 04, 2018 2:43 pm
by hammerdown7
Do you have the dash number and/or last six numbers of the VIN so it can be recorded in the CVOA Registry?

Thanks,
Dick

Re: 76 Vega to S10 Brake System Upgrade

PostPosted: Sun Mar 04, 2018 5:59 pm
by Mark in INdiana
Thank you very much for the information Chuck! Just what I was looking for!
My plan is to use the S10 pickup system figuring replacement parts will be available for a long time. I’ll convert to power brakes so my petite wife can drive it. If available vacuum is a problem, I can use an electric vacuum pump like my Sky Redline has.
At the Moser Engineering web site, they list 12 bolt axle configurations for the S10 2WD and 4WD. For the 1982-19993 models, stock brakes cannot be used. For 1994-2004 there is no mention of brake fittment. So, I presume there is a drum brake backing plate design difference between the years.
Thanks again for the help.
Dick - my Cosworth dash number is 3518.

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Mark

Re: 76 Vega to S10 Brake System Upgrade

PostPosted: Sun Mar 04, 2018 8:34 pm
by hammerdown7
Thanks Mark, yours is the fourth from the last one made, #3518, #3519, #3520 and last is #3522. Someone must have pocketed dash plaque #3521.

Dick

Re: 76 Vega to S10 Brake System Upgrade

PostPosted: Mon Mar 05, 2018 9:32 am
by cosvega76
I can't say for sure about the backing plates, or the length of the axles, for that matter. I know S-10 Warehouse on eBay used to offer a spacer to adapt the S-10 rear disc brakes to the drum brake axle, but I can't find it on their site now to confirm fitment.


Chuck