OE Small Diameter Booster to replace 11" one? [Archive] - Chevelle Tech

: OE Small Diameter Booster to replace 11" one?


Strokd66
Apr 20th, 09, 11:20 PM
I have a 66 chevelle that has the stock style 11" 68-72 brake booster. I need to replace it with a smaller diameter one to clear my BBC. Does anyone know of a smaller diameter booster that was original equipment on something that can replace my 11" one without losing the ability of the 11" one?

OLDED
Apr 21st, 09, 3:20 PM
Look at the Chevy Monzas from the 70's - a nice smaller dia. and good pedal feel. Should bolt up - just be sure to check for the plunger rod length to be the same.

Strokd66
Apr 21st, 09, 4:38 PM
by going with that single diaphragm 9" booster wont I be downgrading?

cwilks
Apr 21st, 09, 4:48 PM
I went from a 11" booster to a 9" booster on my BB "70 Chevelle.....no difference in performance :noway:

vrooom3440
Apr 21st, 09, 5:13 PM
What I did... went to the local Pick-n-Pull wrecking yard and found a '79 El Camino with a 8 or 9 inch dual diaphragm booster. Yanked it out. Whacked the mounting brackets off of my old 11" monster. Modified the holes in the brackets slightly and bolted them onto the '79 booster. Cut off the ends of both booster pushrods, added some threads and a coupling nut.

Bolted it in and works just as well as the old one with much more room around the BBC and tall valve covers.

TMessick
Apr 21st, 09, 8:36 PM
by going with that single diaphragm 9" booster wont I be downgrading?

I haven't tried it, but I would think so. Single diaphragm 9" booster has less area than the 11" job, so the max available force would be less. They can tune the valving to change the RATE of boost (or so I'm told) so you might be able to get the 9" to feel the same up to a point, then you reach max boost on the 9" job (booster runout).

I'd think a 9" dual diaphragm would be a better choice (same area as the 11")

According to RockAuto, you can find these on the following vehicles (among others)
BUICK CENTURY (1980 - 1981)
BUICK CENTURY CUSTOM 1979
BUICK CENTURY ESTATE WAGON (1980 - 1981)
BUICK CENTURY LIMITED (1979 - 1981)
BUICK CENTURY SPECIAL 1979
BUICK CENTURY SPORT (1979 - 1980)
BUICK REGAL (1979 - 1981)
BUICK REGAL LIMITED (1979 - 1981)
BUICK REGAL SPORT (1979 - 1981)
CHEVROLET EL CAMINO (1979 - 1981)
CHEVROLET MALIBU (1979 - 1981)
CHEVROLET MALIBU CLASSIC (1979 - 1981)
CHEVROLET MONTE CARLO (1979 - 1981)
GMC CABALLERO (1979 - 1981)
OLDSMOBILE CUTLASS 1980
OLDSMOBILE CUTLASS BROUGHAM (1980 - 1981)
OLDSMOBILE CUTLASS CALAIS (1979 - 1981)
OLDSMOBILE CUTLASS CRUISER (1980 - 1981)
OLDSMOBILE CUTLASS CRUISER BROUGHAM (1980 - 1981)
OLDSMOBILE CUTLASS LS (1980 - 1981)
OLDSMOBILE CUTLASS SALON (1979 - 1980)
OLDSMOBILE CUTLASS SALON 442 1979
OLDSMOBILE CUTLASS SALON BROUGHAM (1979 - 1980)
OLDSMOBILE CUTLASS SUPREME (1979 - 1981)
OLDSMOBILE CUTLASS SUPREME BROUGHAM (1979 - 1981)
OLDSMOBILE CUTLASS VISTA CRUISER 1979
PONTIAC GRAND AM (1979 - 1980)
PONTIAC GRAND LEMANS (1979 - 1981)
PONTIAC GRAND LEMANS LE (1979 - 1981)
PONTIAC GRAND LEMANS SA 1981
PONTIAC GRAND LEMANS SAFARI (1979 - 1981)
PONTIAC GRAND PRIX (1979 - 1981)
PONTIAC GRAND PRIX BROUGHAM 1981
PONTIAC GRAND PRIX LJ (1979 - 1981)
PONTIAC GRAND PRIX SJ (1979 - 1980)
PONTIAC LEMANS (1979 - 1981)
PONTIAC LEMANS SAFARI (1979 - 1981)

317millhand
Apr 22nd, 09, 12:10 PM
why not just delete the booster all together? i've seen lots more custom cars doing this lately and am thinking about it myself once i get my new brake kit.

Toreadorranger
Nov 23rd, 09, 1:37 PM
im bumping this thread, with a question. I just picked up a stock 72 Abody brake setup minus the master/booster. I will be going with a BB eventually so I would like to get a booster that will clear. Are the dual-diaphram boosters listed below a bolt on job or is it a mix/match or modify my stock booster bracket to get it to work?

I haven't tried it, but I would think so. Single diaphragm 9" booster has less area than the 11" job, so the max available force would be less. They can tune the valving to change the RATE of boost (or so I'm told) so you might be able to get the 9" to feel the same up to a point, then you reach max boost on the 9" job (booster runout).

I'd think a 9" dual diaphragm would be a better choice (same area as the 11")

According to RockAuto, you can find these on the following vehicles (among others)
BUICK CENTURY (1980 - 1981)
BUICK CENTURY CUSTOM 1979
BUICK CENTURY ESTATE WAGON (1980 - 1981)
BUICK CENTURY LIMITED (1979 - 1981)
BUICK CENTURY SPECIAL 1979
BUICK CENTURY SPORT (1979 - 1980)
BUICK REGAL (1979 - 1981)
BUICK REGAL LIMITED (1979 - 1981)
BUICK REGAL SPORT (1979 - 1981)
CHEVROLET EL CAMINO (1979 - 1981)
CHEVROLET MALIBU (1979 - 1981)
CHEVROLET MALIBU CLASSIC (1979 - 1981)
CHEVROLET MONTE CARLO (1979 - 1981)
GMC CABALLERO (1979 - 1981)
OLDSMOBILE CUTLASS 1980
OLDSMOBILE CUTLASS BROUGHAM (1980 - 1981)
OLDSMOBILE CUTLASS CALAIS (1979 - 1981)
OLDSMOBILE CUTLASS CRUISER (1980 - 1981)
OLDSMOBILE CUTLASS CRUISER BROUGHAM (1980 - 1981)
OLDSMOBILE CUTLASS LS (1980 - 1981)
OLDSMOBILE CUTLASS SALON (1979 - 1980)
OLDSMOBILE CUTLASS SALON 442 1979
OLDSMOBILE CUTLASS SALON BROUGHAM (1979 - 1980)
OLDSMOBILE CUTLASS SUPREME (1979 - 1981)
OLDSMOBILE CUTLASS SUPREME BROUGHAM (1979 - 1981)
OLDSMOBILE CUTLASS VISTA CRUISER 1979
PONTIAC GRAND AM (1979 - 1980)
PONTIAC GRAND LEMANS (1979 - 1981)
PONTIAC GRAND LEMANS LE (1979 - 1981)
PONTIAC GRAND LEMANS SA 1981
PONTIAC GRAND LEMANS SAFARI (1979 - 1981)
PONTIAC GRAND PRIX (1979 - 1981)
PONTIAC GRAND PRIX BROUGHAM 1981
PONTIAC GRAND PRIX LJ (1979 - 1981)
PONTIAC GRAND PRIX SJ (1979 - 1980)
PONTIAC LEMANS (1979 - 1981)
PONTIAC LEMANS SAFARI (1979 - 1981)

TMessick
Nov 25th, 09, 12:07 AM
Well, my info was just a lookup of the info on the booster that Steve (Vrooom3440) referenced. I don't know if it's a direct bolt-up or if some tweaking is necessary to make it work...

vrooom3440
Nov 25th, 09, 3:24 PM
It was a bit of mix and match for me ;) See my previous post.

You may be able to find just the brackets on Ebay or something...