Master cylinder bore sizing.

[SPLATT71MC]

I'm going to 4 wheel discs on my 71 Monte Carlo and would like to know what size master cylinder would be best suited for my application. The front is going to be the factory 11" disc set up that will be completely rebuilt and the rear will be The Right Stuff 11" kit using 79 Cadillac El Dorado calipers. I will be installing a Wilwood adjustable proportioning valve and a new booster quite possibly a hydroboost unit. The car currently has factory power disc/drum.

[dontlifttoshift]

1 1/8"

I have thrown so many of those disc brake kits in the garbage. Those calipers were junk in 79, they are not better now. If you brought me the parts and offered to pay me $10,000 to put them on I would tell you to keep your money and rebuild the drums knowing that I would have a happier customer.

Seriously, spend the money on the hydroboost instead and make sure all of your parts are in good shape and you will never miss the rear discs.

[dhutton]

X2 those Cadillac calipers suck big time.

Don

[79 Camaro]

I've had good luck with both 1997 Camaro rear calipers with external e-brake and 2002 Camaro with internal e-brake. 12" rotors. The e-brake on the 2002 Camaro's work better. The 1997 Camaro rear calipers are easier to adapt to the rear end.

[Sinnister69]

Look in classifieds a member has a wilwood master 1-1/8” bore for sale fro a steal

[SPLATT71MC]

So what makes those calipers bad? What's a good alternative using factory parts and fit a 15" wheel?

[jetmech442]

Hey Splat, I actually just wrote a quick section on my experience with the cadillac calipers in the thread above yours. I had them for 8 years on my 442, and never had a hard pedal the whole time. I watched every youtube video, called CPP, rebuilt them, adjusted the living begeezus out of them. i ended up just a little over a year ago direct swapping them for the wilwood d154's without an ebrake. hard pedal....instantly. Many oofs, big sigh. You've had the forethought to ask opinions about them , unlike me who was sold by CPP that this disc brake kit was the answer. dontlift to shift is right, I'd never put them back on my car. 79 Camaro has a good suggestion, I've heard of others using the Fbody brakes with internal ebrake(really wish I'd done that). My only hang up was the 12'' rotor in back being slightly larger than my fronts lol. I hope this helps steer you into a better option. -Scott

[Hotwire]

Agreed with the 1 1/8" bore. I'm running a 1980 Corvette master in my 64 and it works great. Started out with 70s chevelle disc/drum with correct proportioning block, then went to 00 camaro disc/disc setup and only put a wilwood adjustable proportioning valve on the rear line. Running a hydroboost off a 06 Tahoe, the combo works great.

The 00 camaro has internal shoe style parking brake, only thing I did was section the sheathing to make the lines fit my car and put new ends on the cables. System works really well, get about 2" of parking brake pedal travel before it grabs and stops the car dead.