1967 Brakes - Rebuild and Upgrade to Power Brakes

[Richard M.]

I'm planning work on a L71 '67, performing a total brake overhaul using rebuilt o-ring calipers, new PB MC, rotors, hoses, etc. I will also be upgrading to the power brake system. I've worked on 67 PB systems but never installed a upgrade from scratch.

I've gone through the AIM and see I need some additional brackets for the booster, etc. This is my parts list for the project......Zip is my supplier.

DB647 Overhaul Kit
DB600 Booster
DB26 Booster Plate w/rivets
DB616 Booster Pedal Actuator Bracket
DB615 Booster Bolts
DB624 Booster Hose Kit
M2375 Booster Manifold Fitting
WS432 PB Pedal Manual Trans

Is there anything I may have missed? Any advice would be appreciated.

I am also confused about the Master Cylinder. I've read in Nolands book and the AIM, and searches here, that the MC is the same for both PB and Standard brakes, yet I see suppliers have 2 versions for the MC. What may be different about the 2 MC's....smaller bore size on the Power MC?

Thanks,
Rich

[Donald O.]

Re: 1967 Brakes - Rebuild and Upgrade to Power Brakes

I'm planning work on a L71 '67, performing a total brake overhaul using rebuilt o-ring calipers, new PB MC, rotors, hoses, etc. I will also be upgrading to the power brake system. I've worked on 67 PB systems but never installed a upgrade from scratch.

I've gone through the AIM and see I need some additional brackets for the booster, etc. This is my parts list for the project......Zip is my supplier.

DB647 Overhaul Kit
DB600 Booster
DB26 Booster Plate w/rivets
DB616 Booster Pedal Actuator Bracket
DB615 Booster Bolts
DB624 Booster Hose Kit
M2375 Booster Manifold Fitting
WS432 PB Pedal Manual Trans

Is there anything I may have missed? Any advice would be appreciated.

I am also confused about the Master Cylinder. I've read in Nolands book and the AIM, and searches here, that the MC is the same for both PB and Standard brakes, yet I see suppliers have 2 versions for the MC. What may be different about the 2 MC's....smaller bore size on the Power MC?

Thanks,
Rich

Rich,
I think the difference is the push rod length. The MCs are the same.
Now if I'm wrong, which is normal, hopefully I'll get corrected.

DonO

PS I'm considering the same "upgrade" for my 67 with327-350hp, I'm even considering adding power steering too.

[Jim T.]

Re: 1967 Brakes - Rebuild and Upgrade to Power Brakes

I'm planning work on a L71 '67, performing a total brake overhaul using rebuilt o-ring calipers, new PB MC, rotors, hoses, etc. I will also be upgrading to the power brake system. I've worked on 67 PB systems but never installed a upgrade from scratch.

I've gone through the AIM and see I need some additional brackets for the booster, etc. This is my parts list for the project......Zip is my supplier.

DB647 Overhaul Kit
DB600 Booster
DB26 Booster Plate w/rivets
DB616 Booster Pedal Actuator Bracket
DB615 Booster Bolts
DB624 Booster Hose Kit
M2375 Booster Manifold Fitting
WS432 PB Pedal Manual Trans

Is there anything I may have missed? Any advice would be appreciated.

I am also confused about the Master Cylinder. I've read in Nolands book and the AIM, and searches here, that the MC is the same for both PB and Standard brakes, yet I see suppliers have 2 versions for the MC. What may be different about the 2 MC's....smaller bore size on the Power MC?

Thanks,
Rich

Rich I have a 68 with manual brakes, the bore size of the master cylinder is smaller than my 70 which has power brakes. The bore size of the 68's master cylinder is 1 inch and it is the original master cylinder. The 70's bore size is 1 1/8 inch and it is also the original master cylinder. I have rebuilt both of them throughout the many years of ownership.

[Larry M.]

Re: 1967 Brakes - Rebuild and Upgrade to Power Brakes

Rich:

The booster will move the master cylinder further forward in the engine compartment than manual brakes. This will effect the fitment and lengths of the front and the rear brake tubing lines from the master cylinder differential pressure block.....one will be too long and the other will be too short. You may be able to bend to fit, or you will need new PB lines.

The front will not be much of an issue, but replacing the rear line is tedious (but can be done with the body on....I have done it). You could also make a short tubing extension.

Master cylinder push-rod length will either need adjustment or replacement with a different length rod for PB. Not certain. Need to get the correct clearance here for proper brake operation. This should not be a big deal. Just be aware.

Larry

[John H.]

Re: 1967 Brakes - Rebuild and Upgrade to Power Brakes

Rich -

Power and manual on a '67 both use exactly the same master cylinder - you don't need to buy one. You also don't need a brake pedal; the pedal you have now has two holes in it - the upper hole is for the clevis with manual brakes, and the lower one is for the clevis with power brakes. The striker for the brake light switch with power brakes bolts into the upper hole. The power brake pedal pushrod comes as part of the booster assembly.

[Richard M.]

Re: 1967 Brakes - Rebuild and Upgrade to Power Brakes

Thanks for all of the replies......I learned much here.

Larry, I now see in the AIM that there are unique brake lines for power versus non-power systems. Good catch.

John, The replacement MC's have two types, DB335 vs DB336 , why I don't understand. I will call tomorrow to find out why. I do think it's the bore size though, maybe for later years??? The correct reproduction is just one part that is for both pwr vs non-pwr as you say......DB692

Also John, I should have said "pedal pad", not "pedal". I need just the pad.

Rich

[Joe L.]

Re: 1967 Brakes - Rebuild and Upgrade to Power Brakes

Thanks for all of the replies......I learned much here.

Larry, I now see in the AIM that there are unique brake lines for power versus non-power systems. Good catch.

John, The replacement MC's have two types, DB335 vs DB336 , why I don't understand. I will call tomorrow to find out why. I do think it's the bore size though, maybe for later years??? The correct reproduction is just one part that is for both pwr vs non-pwr as you say......DB692

Also John, I should have said "pedal pad", not "pedal". I need just the pad.

Rich

Rich-----


The reason for the difference in master cylinders is this:

1967 Corvettes with standard brakes or J-50 power brakes used the same 1" bore master cylinder as John mentioned. However, 1967 Corvettes with J-56 power brakes used a different master cylinder with 1-1/8" bore size.

What confuses things is that after 1967, the 1" bore master cylinder (same as used for 1967) was used only for standard brake applications. The 1-1/8" bore master cylinder (same as used for 1967 J-56) was used for all power brake applications, J-50 and J-56.