Ok guys, this is my disc brake swap parts check list.

[strokerpost]

Doing the 73 disc swap on my 68 300 and a thought crossed my mind. I got the spindles, discs, calipers and prop valve. My car has power drums, and my question is...do I need the MC and booster off the 73 or will the 68 stuff work? Also, if I decide that I want to put a fresh MC on it...just because, would I want to get one for a 73, or will it even work on my 68 booster? Thanks for any help.

 

[thrashingcows]

The disc brake cars came with a dual diaphragm booster, as opposed to the drum brake booster which is a single diaphragm booster. What this equates to is more foot pedal pressure, and more stopping power. Yes you can use the drum brake booster, and MC, BUT in an emergency stop situation you may not have enough line pressure to lock up those calipers and rotors.

You can run a booster from a 73...if you have the room. They are generally a bigger diameter booster, but shallower from the firewall forward, as compared to the stock 68 disc brake booster. The cardone interchange will more then likely send you a booster from a mid 70's dodge van, or motor home. They have the same basic dimensions, and function the same as the 68 unit, but you might need to grind out the main hole in the firewall to clear the booster piston. I know this through experience....;)

 

[1966newport]

you cant use a drum brake mc

 

[thrashingcows]

you cant use a drum brake mc

Why not? I agree that you shouldn't, but it will still work.

 

[strokerpost]

The disc brake cars came with a dual diaphragm booster, as opposed to the drum brake booster which is a single diaphragm booster. What this equates to is more foot pedal pressure, and more stopping power. Yes you can use the drum brake booster, and MC, BUT in an emergency stop situation you may not have enough line pressure to lock up those calipers and rotors.

You can run a booster from a 73...if you have the room. They are generally a bigger diameter booster, but shallower from the firewall forward, as compared to the stock 68 disc brake booster. The cardone interchange will more then likely send you a booster from a mid 70's dodge van, or motor home. They have the same basic dimensions, and function the same as the 68 unit, but you might need to grind out the main hole in the firewall to clear the booster piston. I know this through experience....;)

I don't suppose you you would have some pix of this you could post up would you?

 

[saylor]

i wanted to jump in on this as im in the same boat - I just went from power drum to disc, not done with the conversion yet. The owner at ECI said I didn't have to change the booster. I asked this very thing - MC only or MC + booster. He said MC only, and it was a NAPA part number what he'd sell me. I just went to autozone tonight and picked up M1633. http://www.autozone.com/autozone/parts/_/N-8kn47?itemIdentifier=227207_0_0_

15 bucks

its supposed to be 4 bolt bolt-on fit. 1 1/32 bore. onto the drum booster. ill be bleeding it out this weekend. we'll see how it goes.

with the ECI kit, its 1980~ Camaro brakes, and the hoses from frame to caliper were too short. I got some 6" brake line extensions out of the back room of autozone, and some couplers...

 

[thrashingcows]

I don't suppose you you would have some pix of this you could post up would you?

Here is the set-up I did on my 68 T/C wagon. 73 C-body disc brake set-up, with a Cardone replacement 68 disc brake booster, and an aluminum MC from a 80-90's Dodge ram van or truck...and an adapter to go from 4 bolt MC to a 2 bolt MC.

Here is the part of the booster that won't clear you firewall hole....the hump below the rubber boot.



I used my dremel to open up the hole...





Then installed the new booster...you can see it doesn't look correct for a 68 Disc booster...but functions the same.



And then the adapter and new MC.



I had to adjust the push rod length coming from the booster to the MC. But other then that it works great!

 

[strokerpost]

Thanks a bunch for the pix. You say you had to "adjust" the pushrod length, I wondered about that. How much did you have to alter it by, did you have to lengthen or shorten it?

 

[thrashingcows]

Well it depends on the MC you end up going with. Since I had the adapter, and then the newer style MC, I ended up having to shorten it a bit. Brakes were dragging. Causing me all kinds of nightmares for a long time before I finally figured out what was wrong.