Working on my late fathers 70 challenger. The master cyl is leaking fluid inside the car. When looking at replacement masters all the ones that look like the one on the car are listed as power 4 wheel drum. The car is a manual 4 wheel drum. I remember my dad putting a master on the car a long time ago, possible he got the wrong one? I was going to rebuild it if correct, replace if not. Thanks for any info.

That looks like the right one for drum brakes.

Cast in the bottom of it if it is correct will either be 2225001, 2660909, nothing or AANF

do power and manual drums use the same master? Thanks for the info. Can't read the bottom of the master. i'll have to pull it off and clean it up

I'm pretty sure they are the same but Mastershake340 is our resident expert.

The one you have is the same as what is on my manual drum brake 70 Hemi GTX

Looks correct to me. 2225601 is one of the correct casting numbers.
The only difference between manual and power drum master cylinders is the manual version has a dust boot installed on the flange at the bore.

Not correct for power disc.

His question was whether it was correct for power drums

Power brakes will often have a larger internal cylinder than will manual. You probably should get it correct for your car before buying a new one.

Small cylinder equal more brake shoe pressure, longer pedal throw. Larger cylinder equal less brake shoe pressure with shorter brake pedal throw,,,,braking pressure is enhanced by power brake booster.

Definitely the correct 4 wheel drum master. All the Cardone and other rebuilders that you buy at the typical parts stores are completely wrong, please rebuild the one you have!

Service manual specs shows 1" bore MC for drum brake applications whether 6cyl or V-8 & HD. Disc brake setup has 1 1/8" MC bore.

For drum brakes there is no mention if its used for power or manual. Here is a quote from the Service Manual. "The MC used on vehicles not equipped with power brake units is serviced in the same manner as the MC with power brakes, with one exception, the MC for power brakes does not include the push rod." Hope this helps.

'70 E body disc brake master cylinder was 1" bore also, for all engines except hemi. Disc brake hemi E bodies were the only cars that got a 1-1/8"

thanks for the info! I'll get my kit ordered so i can at least have brakes again.

Good luck, hopefully the bore is not pitted to badly that replacement seals don't stop the leaking.

Brakes are good

If it ends up leaking after rebuild, send it up to Brake and Equipment warehouse for a sleeve.

Table of 1970 Master cylinder applications
http://www.imperialclub.org/Repair/Lit/Master/274/page13.htm

You guys called it. Even after a good hone the bore is so pitted that i'm not even going to try an install the kit. The holes in master leading to the bore are clogged and the whole thing is full of sludge and rust. Tried oreillys, napa, carquest, etc and they all have the wrong master. I'll have to look into getting it sleeved. It is casting #2225601. Thanks!!

Per Mastershake's recommendation, I shipped my m/c off today to Brake and Equipment Warehouse to be sleeved.

calling myself in the morning. Do they overhaul it as well or just sleeve?

They will just sleeve, or can rebuild it also for you.