Brake Boosters what's the difference?

[gearhedjon]

Hi guys, Does anybody know why early G-Bodies/A-bodies have different brake boosters? It looks like the early years get the bigger booster ( larger diameter) and the 81-88's get the small booster. Any difference? Why the change in boosters?

 

[pagrunt]

To be honest I have never really noticed any difference between the single or double diaphram boosters in braking performance. I like/prefere the double diaphram one gause the look cleaner & don't take up as much firewall space.

 

[gnvair]

Although there was not a specific option for the brakes I have noticed that the dual diaphragm seemed to be most common on cars with F41/heavy duty suspension. But that isn't necessarily gospel.

 

[565bbchevy]

I still have the factory 9" dual diaphragm booster in my 83' Monte and it works well and also gives me the clearance I need for my BBC and IMO looks better than the pancake style single one.
And my car did come with factory F41 suspension.

 

[pagrunt]

My '81 Monte was originally a very basic 229 V6 car with out F41 suspension & came with the dual diaphram booster.

 

[Doug213xrj]

My 78 El Camino has the small thicker brake booster and my 81 Malibu has the bigger thin brake booster. So is the smaller thicker one the dual diaphram booster ?

Doug

 

[pagrunt]

So is the smaller thicker one the dual diaphram booster ?

Yes.

 

[64nailhead]

There are two differences that I'm aware of : single diaphram (thin and larger diameter) and double diaphram (thick and smaller diameter), and second the master cylinder diameter bore is larger starting in '81 (I believe in '81, but could possibly be in '82).

 

[pagrunt]

I believe in '81, but could possibly be in '82

It's '82 with the no/low drag calipers. Believe another difference is '78-'81 have iron master cylinders, '82 up are aluminium.

 

[gnvair]

The brake booster is up there among the items that varied with no rhyme or reason. Other items I have seen variations on
are the steering boxes (605 vs 800) although F41 would have the 800 with variable or fast ratio depending on year.
aluminum rear brake drums
front air dam sizes
aluminum bumper supports
aluminum radiator supports
aluminum hoods and trunk lids
a/c compressor design (radial vs axial)