Brake booster size?

[OL SKOOL]

The truck is a 70 gmc with manual drum brakes now. I am putting on disc brakes on the front, drum rear. I would like to know if a 8" booster and 11" booster have the same feel on the pedal. Will the smaller booster require more foot pressure?
























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[mongocanfly]

Bigger=more assist...

[OL SKOOL]

That's what I was kind of thinking too. I know the last 71 I had was the 11" booster. The smaller booster I like the looks better but don't want to sacrifice performance. Thank you.

[SunSoaked]

Some small diameter boosters are dual diaphragm and actually have more assist than larger single diaphragm versions. Same principal as dual disc clutches. Know what you have.

[OL SKOOL]

Originally Posted by SunSoaked

Some small diameter boosters are dual diaphragm and actually have more assist than larger single diaphragm versions. Same principal as dual disc clutches. Know what you have.

I had manual 4 wheel drum. I know from the factory with disc brakes they had the 11" but I have nothing to compare with. I just don't want to do this upgrade and then have to stand on the pedal to stop. I have everything bought but the booster/master. So your saying the 8" dual should work fine? The pedal pressure will be less then the 11". Have you ever used one? Thanks for the input.

[SunSoaked]

I'm saying that a dual 7 inch diameter boosters will have the same assist as a single 14 inch. Either will work, just depends on if you want more or less pedal effort and the space available. 11 inch is stock in your case, if you want less pedal effort use the dual 7".

[OL SKOOL]

SunSoaked Thanks for the info I would like to use the smaller one that's why I was asking. I have a Capt. Fab. brake mounting bracket I want to use but the shift linkage on the column was hitting the booster with the 11". This way I can move the mc /booster against the firewall and get rid of that ugly factory mounting bracket/linkage.

[Captainfab]

On the '67-'72's with a column shift, I believe you can go as large as a 9" dual diaphram.

[OL SKOOL]

Originally Posted by Captainfab

On the '67-'72's with a column shift, I believe you can go as large as a 9" dual diaphram.

I bought your bracket a very nice piece probably 3 years ago. My quick little 6 month project ballooned into a frame off. Finally getting down to some of the last pieces of the puzzle. I had heard so many different stories about the pedal pressure. I just wanted to check with the guys on the forum with real life experience . I will check into a 9" dual booster. Thank you much.

[Captainfab]

One of the S10 boosters on the list of compatible boosters that came with the booster bracket is a 9" dual diaphram.

Originally Posted by OL SKOOL

I bought your bracket a very nice piece probably 3 years ago. My quick little 6 month project ballooned into a frame off. Finally getting down to some of the last pieces of the puzzle. I had heard so many different stories about the pedal pressure. I just wanted to check with the guys on the forum with real life experience . I will check into a 9" dual booster. Thank you much.

[lutronjim]

Will the S10 9" dual 'petal rod' work with the CaptainFab bracket? And while I'm at it, is the S10 'push rod' the same length of a 11"?

Thanks

[Captainfab]

All of the factory boosters that are compatible with all of my booster brackets will need the booster pushrod lengthened to reach your peDal.

[OL SKOOL]

Originally Posted by Captainfab

All of the factory boosters that are compatible with all of my booster brackets will need the booster pushrod lengthened to reach your peDal.

I have a 2002 s10 here with 43,000 miles that was crashed. I'm just not real fond of the looks of the master setup with the plastic cups.10-4 on a longer pushrod. Maybe a different master with my booster will work. Little more detective work to do. Going for a more stock look but a few up grades. Never liked the big gaudy mc/booster hanging 2 foot in the motor bay. Thanks for all the help Captain.

[Captainfab]

You do not have to use the master cylinder that comes on a given booster. You just need to be sure that the depth in the back of the master cylinder piston is the same as the original master for the booster.

A customer just sent me an email today with info on the aftermarket dual diaphram booster he is using. It is from Tuff Stuff, part #2229NB. This one is yellow zinc plated.

[67 Burb]

If you're mixing and matching master cylinders and boosters, here's the tool that would save a lot of headaches. It lets you know if you have the proper clearance between the booster and the M/C pushrod. From mpbrakes.com

They have a video on their web site showing how to use it.

[OL SKOOL]

Originally Posted by Captainfab

You do not have to use the master cylinder that comes on a given booster. You just need to be sure that the depth in the back of the master cylinder piston is the same as the original master for the booster.

A customer just sent me an email today with info on the aftermarket dual diaphram booster he is using. It is from Tuff Stuff, part #2229NB. This one is yellow zinc plated.

Thank you I will check into some of their stuff today.

[OL SKOOL]

Originally Posted by 67 Burb

If you're mixing and matching master cylinders and boosters, here's the tool that would save a lot of headaches. It lets you know if you have the proper clearance between the booster and the M/C pushrod. From mpbrakes.com

They have a video on their web site showing how to use it.

I made something similar years ago with some threaded rod, lock nuts and flat stock. Thanks for the help every little bit helps.

[67 Burb]

Originally Posted by OL SKOOL

I made something similar years ago with some threaded rod, lock nuts and flat stock. Thanks for the help every little bit helps.

I was thinking of doing the same - making one up. MPB wants $48.00 which I think a bit more than I want to spend on a tool I might only use once.