c3 power brake upgrade

[Ed Driscoll]

HI Folks, I've been thinking of putting power brakes into my 68 c3 and have been told that the pepal position is different then manual brakes. i've also been told that there is a retrofit kit that makes this job doable. Has anyone any knowledge on this?
thanx
Ed

[Joe L.]

Re: c3 power brake upgrade

Ed------

You won't gain enough from the conversion to make it worthwhile. I don't know of any kit, per se, but someone like Master Power Brakes may offer one. Basically, what you need is the power brake master cylinder, power booster, and new brake lines from the master cylinder to distribution block.

On original installations the firewall panel and the underdash bracket were different. However, your existing parts can be converted for a power brake installation. The underdash work and conversion is the most difficult part of the job.

[Ed Driscoll]

Re: c3 power brake upgrade

Thanks Joe,
i was told that the manual brake underdash braket has a different fulcrum relative to the pedal then the power brake unerdash braket. do you know if this is correct?

[Terry F.]

Re: c3 power brake upgrade

It is best to get a complete set up out of another 68 corvette. There are some differences in 69 and later corvette clutch brake pedel assemblies (mainly the brake light switch that I know about). I don't know if they are different enough to stop a person from trying though. I just looked at two 68 set-ups, one power and one manual. The pedels measured the same and all but the bracket that they attach to is slight different between the two items I have. But It is hard to see under my dash even with everything out of there. Without looking I know that the fiberglass section that attaches to the fire wall is different and also the sheet metal piece that rivets to the inside of the fire wall is different. If you want to do a nice job, you will need those items. The pedel assembly may or may not be different. Like I said, the pedals look the same and measure the same, the backet that holds them looks diffenent. I don't believe the assembly manual discriminates between the two, I have looked at that in the past. Best to scavange a unit out of another 68. I have heard of people making things work but I am not into drilling holes and cutting wires. Best regards, Terry

[Chas Henderson #28127]

Re: c3 power brake upgrade

I would think the A.I M. manual would show you and list all the differant pieces if you read it well enough. You should be able to compare the parts list and drawings to easily figure it out. Remember, P.B. is in the rear of the manual , as it is an option.

Chasman

[Mark #28455]

Re: c3 power brake upgrade

I did this conversion on my wife's 1970 big block. It did definitely improve braking to where she can easily drive the car. The pedals were the same. The bracket that the pedals were attached to was definitely different. The manual brake bracket has two welded nuts against the firewall and two captured carriage bolts whereas the power brake bracket has four plain holes for studs on the power booster. In addition, the bolt spacing is about 1/2" different and the big hole for the master cylinder on the manual brakes vs. the booster input rod is in a slightly different location - all were easily adjusted with a hole saw and a round file and are not visible as they are hidden by the booster. For the 1969 and later pedal, it appears the power brake with automatic bracket is identical to the 4 speed bracket (and a whole lot cheaper on e bay). The power brake pedal does sit about 3/4" closer to the floor. I think I purchased my original "kit" from Zip products and it even included the vacuum tube that atytached to the intake manifold and the appropriate nipple. Once I bought the correct pedal bracket, it was quite easy! Good luck!

[Chuck S.]

Re: c3 power brake upgrade

Once I bought the correct pedal bracket, it was quite easy!

Sorry, Mark, I can't believe it got ANY easier until after you got the lock nuts on those four booster studs under the dash. It was definitely downhill after that.

By the way, that was good, timely input. I thought the brackets were different and the power brake pedal set lower, but I couldn't remember anything that would confirm it for me.