are there any master cylinder upgrades for our cars?

[G_Body_Enthusiast]

they're no different than other g-body brakes ive driven. like i said, i just think they're too soft. i like a firm pedal. stock g-bodies do not have a firm pedal in my opinion. so you dont think stock g-bodies have a mushy pedal, good for you. doesnt mean everyone else shares your opinion or if theirs differs from yours they're stupid and dont know how to work on brakes.

I've owned several G body cutlass' and have to agree with G body enthusiast....Most of them had too much pedal travel and a spongy feel. Some of them were low mileage cars. I'm interested in hearing more about your B body master swap...let us know what you come up with.

i think i have my mind set on a master cylinder and booster for an 89 caprice. its larger by 4.6 mm and 4mm respectively. that's an increase in diameter of about 19.2% and 11% or so over the stock unit (24mm and 36mm) to 28.6mm and 40mm which is quite a step up i think. i should be able to easily notice a difference when i swap the master and booster out. if i use the two piston caliper brakes from a blazer that use a 1" master that's 1.4mm larger than the g-body unit which i think would feel a little worse without swapping it out for something bigger. so i think i'm starting at the master/boost and working my way out. i have braided hoses instead of the regular hoses to help cut down on that spongy feeling a little bit. they swell less so the pedal should be a little firmer.

i'm sorta guessing since i dont know what the exact volume is for the calipers i have and the ones i want to use. i just know if i change the volume needed for the caliper the master should be changed to match the extra volume needed. i think i'm making a decent educated guess on this and i'll find out later if i'm right or wrong. i think i'll be happier with the increased pedal effort and the extra clamping force.

 

[Bonnewagon]

G-body you are on the right track. It's simple fluid hydraulics. The stock master has a small bore which feeds the calipers and drums quickly and with little effort, but that translates into a long travel mooshy pedal. Think 2 ton car jack, same principle. Substitute a larger bore with more volume and the pedal effort increases because you are forcing more volume into the same space. Thus the pedal travel shortens for the same reason. If we only had manual brakes we'd be searching for the smallest bore to make pedal effort easier, but with a power booster we can use the largest bore available. It's a cheap upgrade and make our car's brakes seem better than they are. Read this if you can find it-

 

[G_Body_Enthusiast]

G-body you are on the right track. It's simple fluid hydraulics. The stock master has a small bore which feeds the calipers and drums quickly and with little effort, but that translates into a long travel mooshy pedal. Think 2 ton car jack, same principle. Substitute a larger bore with more volume and the pedal effort increases because you are forcing more volume into the same space. Thus the pedal travel shortens for the same reason. If we only had manual brakes we'd be searching for the smallest bore to make pedal effort easier, but with a power booster we can use the largest bore available. It's a cheap upgrade and make our car's brakes seem better than they are. Read this if you can find it-

barnes and noble has it for 15 bucks. i'll make sure to pick it up some time. i'm guessing it has some math equations in it to help figuring this stuff out easier/more exactly. it's one thing to have a general sense of what you need to do it's another to know exactly how much more volume you need for new components allowing you to find a better matched master cylinder allowing for a more well balanced brake system. brakes are a safety issue and i dont like taking chances if i dont have to. this book will help i'm sure.

 

[Bonnewagon]

I consider it my Brake Bible. If you are a math wiz you will find calculations to get whatever results you want. But just the general knowledge will educate you how and why brakes do what they do and how you can improve yours.

 

[1bad79]

i wonder if he refers to his car as the catmobile?

lol

 

[84dragcutlass]

I think they ran an episode on muscle car tv or something like that on breaks a long time ago, true we can use the simple principals to make are breaks feel firmer with less travel but the term used by Bonnewagon was better than they are for a reason. Just be careful and dont push it to hard before you upgrade the rest of the system or it will be all feel and no brakes. Just dont want see any of our fellow gbody drivers get hurt, but you of course know your car and know what it can and cant do. Sure wish i could get ahold of a set of those black torque thrusts with the chrome outer ring in a 17 or 18, would help my olds out a lot

 

[black_aerocoupe]

I wanted aluminum and bigger bores so I got a reman. Caprice master for a vaccuum 12" brakes V8 model the same year as my car.

The brand new Caprice ones listed at the time seemed to all be iron.

 

[bill]

Just a thought....Ive heard that Steel Braided brake hoses make a big difference on brake feel and performance....

 

[Longroof79]

Just a thought....Ive heard that Steel Braided brake hoses make a big difference on brake feel and performance....

They allegedly are supposed to firm up the pedal somewhat. I've used them in two Porsches and have a set of Russell braided hoses for my wagon that I have yet to install.
They firmed up the pedal in one of the cars. The other car still had a problem with a spongey pedal. I attribute that to using silicone brake fluid.
The braided hoses apparently don't expand like stock rubber hoses. That's what's claimed anyhow.

 

[black_aerocoupe]

Yes Bill, there are a lot of stock flex hoses still out there. 😢