How to convert power to manual brakes on a C3

[Bill S.]

On my C3 I would like to convert my power brakes to manual brakes. The opening on the firewall is larger for power brakes than a manual brake system because of the brake booster. If I convert to a manual brake system I need a plate to fasten to the firewall which would enable the master cylinder of the manual brakes to be mounted to. Does anyone know who manufactures this plate? Also, is there a kit on the market which would provide the plate and whatever other components necessary to have a complete manual brake system?

[David H.]

Re: How to convert power to manual brakes on a C3

On my C3 I would like to convert my power brakes to manual brakes. ...

Bill

Curiosity. Gotta ask. How come? All had power brakes starting 1976.

Dave

[Patrick H.]

Re: How to convert power to manual brakes on a C3

Bill

Curiosity. Gotta ask. How come? All had power brakes starting 1976.

Dave

Same thought here.

I have a 71 without and 72 with.
I wouldn't add power because it's a PITA to do that, but I sure wouldn't remove it!

[Scott P.]

Re: How to convert power to manual brakes on a C3

Bill, you need to look in the AIM on the manual brakes page & PB page, you will find the firewall fiberglass piece is a different one and the metal mounting bkt behind the firewall fiberglass is different for manual and PB. Both can be changed out and should be for a good working brake system. The inside metal is the real important part because it moves the brake pedal leverage point to where it should be. A Corvette salvage yard would be a good place to find the parts. Scott

[Bill B.]

Re: How to convert power to manual brakes on a C3

Hi Bill,

To give you an idea, see the pics below. I converted my manual brakes to power brakes on my 1970. The first pic depicts the original manual brake firewall, with my preliminary markings in red of new hole positions required to mount the booster. (turns out, they were wrong as I tried centering the booster with the existing master cylinder center hole) The second pic is the firewall shown from the inside the cockpit looking forward. The third pic is the modification I had to make to the mounting bracket that Scott mentioned. The last pic is the completed mod to the firewall.

(from the preview, looks like the pics may have gotten rotated 90 deg when I attached)

Hope these help you understand the mods required. (I am also of the camp to keep the power brakes installed, but as an owner, I do understand it is your car and you can do what you like with it)

Manual Brakes.jpg

Inside .jpg

modified metal.jpg

completed.jpg

Keep in mind that the metal clutch/brake bracket that came with a factory Power Brake installation is going to be different and require the opposite of the mods I performed. (the bottom holes will need to have welded nuts added and the top square cut-outs added) May be easier to obtain a used bracket as Scott suggested.

[Dan B.]

Re: How to convert power to manual brakes on a C3

Same thought here.

I have a 71 without and 72 with.
I wouldn't add power because it's a PITA to do that, but I sure wouldn't remove it!

Well said. I had a 70 with manual brakes and never once gave a thought to adding power. That being said, it would not be hard to glass the larger opening over and reconfigure if you really want to and fabricate a plate as needed.

This is the first time I've heard this type of request, and as asked would be interested to know what made you think of this.

[Bill S.]

Re: How to convert power to manual brakes on a C3

Scott,

Thanks for the reply.

Regards,
Bill

[Bill S.]

Re: How to convert power to manual brakes on a C3

Bill,

Thanks for the pictures and reply.

Regards,

Bill