Power booster differences

[dodge68charger]

Doin some research i noticed that the power disc brake cars and power drum brake cars came with different power boosters for each setup. I have 4 wheel power drums on my 68 b body..Will this make a big difference if i want to convert to discs on the front and drums on the rear? Does any company make boosters for the disc/drum setup And also does any company sell a disc/drum master cylinder for less than the price of a small family lol..Thanks

 

[Propwash]

Yes...It makes a difference. The power assist ratio (pedal travel to assist ratio) is different between the two. Simple way of looking at it would be, why would there be a different booster for a disc-drum car and a drum-drum car? The disc booster is a dual diaphragm and provides greater assist.

Here's a couple sites that have a bendix style disc/drum booster.

http://www.rockauto.com/

http://www.napaonline.com/

Do a part # search for 5473603 (booster only) or 503603 (Booster & Master cylinder combo)

One more thing..If you go this route, save the linkage of the backside of your drum booster. It will bolt right up to the Bendix style booster and to your pedal assembly. You'll also need the booster plate for the backside of the booster:

http://www.megapartsusa.com/proddetail.asp?prod=102-BB4

Good luck

 

[dodge68charger]

Thank you for the help. Really appreciate it! Would this booster setup work with wilwood or ssbc front brake kits that include the rotors and mount to drum brake spindles.

 

[Propwash]

No problem, went through the same scenario as you a couple times now. The least I can do is try to give you some insight to what I found out piecing it together. As far as the addition of Wilwood/SSBC, I'm guessing it would. I would still give them a ring and specify the booster you have and see if there is any compatibility/fit issues with their product. I'm sure they would dial in the correct Master Cylinder Bore to Match the Calipers for you. I'm also guessing they would, but I would also confirm with them that they incorporate a residual valve in the master being you plan on keeping the rear drums. You will also require a proportioning valve moving up to a front disc system. You do have a few options there 1) Upgrade to the factory Mopar proportioning valve system (RightStuff, Roseville moparts and others have them),2) buy a combination Distribution/Proportioning valve (Wilwood makes them), or 3) install an adjustable proportioning valve in the line to your rear brakes.

 

[dodge68charger]

If wilwood or ssbc cant help me out is there any other route i can go for front brakes using a bendix disc/drum power booster like using newer spindles and rotors from a mid 70s car that would bolt up. Thank you

 

[Propwash]

Yes....I won't dive into it because there is quite a few options, but here is an article that will answer your question(s):

http://www.moparaction.com/tech/archive/disc-main.html

I converted my roadrunner using a Bendix booster, a 1 1/8" disc/drum master and the Right Stuff spindles, calipers and rotors. I converted a '70 Satellite using '74 A-Body Disc equip. The routes you can go are endless (as you are finding out). Just a matter of understanding the braking components and how they work, how they would work together and why. Just a matter of putting in the footwork and you'll end up with a breaking system to meet your needs/wants.