I am looking for the easiest way to upgrade my '70 Chally manual drum brakes (R/T, 11"). Is there a way to swap out the master cylinder for a power booster and master cylinder? (I guess I have to get a new proportioning valve).


- John

I did not change the porprotion valve when I did mine and it works fine.

I don't need to change pedal do I? Do I need to buy a disc brake booster mounting plate to go between the firewall and the booster?

The pedal linkage is different - the PB linkage has less mechanical advantage. The manual linkage with a power booster woul be real touchy.

I'm not sure if there is a plate change.

The drum/drum boosters are still available reman from your local parts store at reasonable cost. Masters are available also... but reman masters seem to be hit and miss on quality.

I bought a '70 Challenger with the factory drum PB setup. It was easy stopping with 4 "self energized" drum brakes and a booster. Not the most even left to right though. I didn't try repeated high speed stops until I upgraded to disks in the front. Personaly, if I was going to tear into it enough to put the booster in I'd go ahead and put front disks also. Its a big improvement.

An easy - but not cheap - way to make the switch is to call Master Power Brakes or look at their website. They seem to specialize in PB upgrades to MB cars.

Yes you will need to use a power brake bell crank on the pedal and rod set up inside. no big deel thay are on the bay quite offen for around 50 skins. give or take. No pedal change. It not a hard thing to do and you will be glad you did it.

My rebuilt power brake booster and master cylinder arrived today. It appears to be the correct Bendix type that supposedly came on '70 E-body power drum brake cars. On the booster, there is 3 1/2" between mounting bolts one way, and 3 1/4" the other way. Looking at what I have now, I don't think I can reuse the reinforcing plate that is on my current manual brake master cylinder. Does someone have a picture of the mounting/reinforcing plate for a '70 E-body power drum brake car? Thanks in advance.

It would be worth calling Texas Acres - a MOPAR only salvage yard in Texas. The owner is retiring but still may be able to help you out with the plate. They are on the web.

Thanks, AHY - you da man....

70GTX,

I believe the reinforcing plate that you require will have more of a elongated shape/hole, similar to the firewall opening. Did the reinforcing plate you removed just have a round hole opening? A disc brake car may use the same same plate that you need.

Not knocking your plan but I would go to manual disks before switching to power drums any day of the week.

I agree, but very busy this winter - and don't want to fool with pulling spindles, etc

Attached is a pic of the reinforcement plate I think is needed for power drum brakes. Its from a Mopar kit.

http://cgi.ebay.com/ebaymotors/ws/eBayIS...RK%3AMEWAX%3AIT