I would like to put power brakes in my '73. Is there more that just getting the booster, master cylinder, and two new brake lines that go from the master cylinder to the valve on the frame?

 

If you don't already have one, get an AIM for your year and look up the schematics for both systems. Aside from some cutting and a number of smaller details, the booster mounts differently, uses a different push rod, and that rod uses a different attachment point on the pedal. Easier to understand all this and properly account for the necessary bits with that AIM...


TSW

 

Thanks. My AIM arrived today.

 

Take a look at the cowl drilling diagram, usually near the front of the AIM. Read over it until you find the note about drilling the cowl for optional power brakes. If memory serves, you need a slightly larger hole for the booster than non PB cars, and two additional holes for mounting bolts.

 

IF you have power steering, maybe look into doing a Hydroboost conversion and save a bunch of headaches with that soft pedal feel the way other cars have, only accentuated a goodly bit....

 

I did this write up somewhere around March of this year and again in 2008. Hope it helps.

Keep in mind; I’m doing this from memory so if anyone wants to add to this feel free!

You will need both the power brake booster and a new master cylinder. Power brake and standard brake master cylinders are different.

The cars with standard brakes have two studs on the firewall; you will need to knock these out of the firewall (they will fall inside the car).

Then using the two upper holes from the studs as a guide, mark the lower holes and drill them for the lower booster holes.

Once you do this, you’ll need to enlarge the hole in the firewall for the rod from the power brake booster. Yes it bolts to a different position on the pedal but doing this is real easy. If you look under your dash you’ll see a round hole on a non power brake car. On a power brake car it was egg looking. The inside reinforcement should for both power and standard had this egg looking hole made in to it and if you look under the dash you’ll see what portion of the fiberglass you’ll need to remove.

The standard brake and power brake lamp switch bracket were different, the power brake one is now available new. http://willcoxcorvette.com/product_i...ducts_id=12540

Hope this helps, I used to have a detailed sheet somewhere on this when we did a conversion many. .. Many years ago. If I can find this I’ll post it for you.

18243




Willcox Inc.

 

I did a conversion from manual brakes to a hydroboost setup, total cost was under 300 USD (already had the lines and the M/C), one of the best mod. I've ever done to my car.

 

Hey Wilcox,
Thanks for that info, I've printed it out, and I know it'll be of great use. I couldn't use the link for the part, can you print the part number so I can order one.
Thanks

 

Sorry about that..

http://willcoxcorvette.com/product_i...ducts_id=12540

 

I keep reading your instructions from above, just can't figure out what you mean by,

"Then using the two upper holes from the studs as a guide, mark the lower holes and drill them for the lower booster holes".

Those aren't the two holes from the stud's that I just knocked out, are they?

 

See if the pics in this thread along with Ernies write up will clear it up.
http://forums.corvetteforum.com/c3-t...er-brakes.html

 

Yes, great pictures, but it looks like they're using the bottom holes as a guide and drilling the top [just above the existing holes for the master cylinder]. Wilcox say's use top holes [where the master cylinder is now] as guide and drill bottom.

 

I have the two top holes where the master cylinder currently resides, also about 3 inches below them is another set of holes, which have 5/16 -18 threaded nuts attached to the bracket that holds the brake and clutch pedals. Do I need to drill out and make those holes bigger so the studs on the booster [which appear to be 3/8] will fit thru them?

 

Yes you will have to drill out the lower holes and using the gasket as a templet mark and drill the upper holes.

 

Thanks Roger, I'll give it a try.