Original 69 Z28 Master cylinder- no power brake booster?

[rally]

Gentlemen i have a question about my original brake master cylinder on my 69 Z28. When i bought this used Z28 it came with no power brake booster but has a original master cyliner casting number 5468309 which is a correct Z28 piece.  This car has front disc brakes. Whats going on here, why no power brake booster. Did some Z28s not have these installed with the front disc brake setup? All the brake lines going to the master cylinder are original and never have been changed or modified. Could this car have been a drum brake unit and someone may have installed these disc brakes? My Z28 is currently setup for drag racing. Could have someone removed this power brake booster because of low vaccum on the drag engine and wouldnt operate the booster correctly? I am puzzled here. Any input is greatly appreciated.

[Gramps69Z]

All Z's came with power disc brakes. You car was modified.

http://www.camaros.org/geninfo.shtml#Z28

[rally]

Modified in what way? I dont understand your answer, can you explain that more in depth. Alright my Z came with disc brakes, why no brake booster behind the corrrect master cylinder? Are all disc brake applications on 69 Z28s suppose to have a brake booster, or did some Zs come without them?

[tom]

Power disc brakes were required. If you don't have them, your car has been modified. Either it didn't start out as a Z, OR it did start out with power disc brakes.

[rally]

Tom i do have power disc brakes up front right now. But no brake booster, puzzling.

[tom]

The booster was part of the power brake package.

[rally]

The only thing i can think is the previous owner removed the brake booster when he set the car up for drag racing. The engine i have in it now has very low vacuum, and maybe thats why he removed it, does this make sense to you? Should i put a brake booster back on it? I want to get this car back on the street in a few years after i quit drag racing. More input would help Tom, so far you input has been huge.

[tom]

You need to start by finding out how power is working without the booster. Is there a vacuum resovior someplace else? Racers have been know to relocate weight. Is there a vacuum pump? With low vacuum that is one solution to power brakes. No telling what may have been done over 40 years. There are many better than me on this site. They will chime in eventually, especiazlly if I make a mistake. Merry Christmas, health & good fortune in the new year. I'm out for today.

[rally]

Yes i will check this out about the vaccum resovoir. Makes sense. And like you said where is the power coming from.

[acelr8]

This is very simple. The car (if real) had a brake booster factory.It was removed for low vacumn and/or valve cover clearance.
Has Manual disc brakes not power now.Very common in the race car world.Jeff

[JohnZ]

This is very simple. The car (if real) had a brake booster factory.It was removed for low vacumn and/or valve cover clearance.
Has Manual disc brakes not power now.Very common in the race car world.Jeff

I agree - somewhere along the line an owner simply removed the booster, and installed the manual brake pushrod and clevis from the pedal arm to the back of the master cylinder (the pushrod and clevis on a power brake car are part of the booster). There are two holes in the brake pedal arm for the pushrod clevis pin - the upper one is used for manual brakes, and the lower one is used with power brakes.

[rally]

John i really appreciate the breakdown on my situation with my Z28. I will look over this whole setup and see what they did. This is a big help now and when i decide to quit drag racing my Z i know what i have to do to install the brake booster and the correct hole to setup it back up. Thank You very much.
Rally

[Z10Mike]

Agree with the theory about removal for drag racing.  I bought a z-car years ago that was set up the same way for drag racing.  It was a bear to stop so I replaced the booster so I could drive it on the street.

[rally]

Mike,
I agree my 69 Z28 is a bear to stop on the strip without the power booster being off the car. I need all the shut down on the strip to slow my car down with the manual front disc brake setup. With a 468 ci BB Chevy and 128 MPH thru the traps i have to bear down hard on the brake petal. You are so right there.