Dinking around with 71 Demons and Dusters I have seen too many variables to make the call on what is correct or not and could use some input from you guys.

In 1971 you got:

Manual drum brakes (standard)
Manual (front) disc brakes
Power drum brakes
Power (front) disc brakes

I've seen 3 basic styles of master cylinders used (looking at what APPEAR to be original cars) some appear to be the wrong ones based on the information I can find.

What I am trying to determine is which style would be correct for a 71 with manual disc brakes. The pictures I'm posting are examples I have seen so far. First up are a survivor 1971 Demon and a survivor 1972 Duster both equipped with power brakes (I believe both also have front discs, I will verify and post later). Notice how the front of one MC is flat while the other is rounded.

Here's a 71 with manual disc brakes....Again, a survivor, but I can't say if the MC is the original or not. Looks like the same MC the orange 71 Demon has with power discs. Notice the bail wire is reversed.

I can take a picture of a Challenger Drum Brakes all around Master with Dana if that will help, original Master.Not sure if E and A used the same stuff in 1971 and have not looked in the parts book. You might also want to Message Mccannix he seems to be up on this stuff far more than I am.

Sure, can't hurt, thanks!

Scott,this is/was my 71 Canadian built one of 75 340 Swinger,original master cylinder,best picture I have.

Discs or drums up front Bill?

All of the cars so far have disc brake master cylinders. You can tell because they have a big reservoir and a small reservoir. The drum masters will have equal size reservoirs.

JeffC,

That's what I thought as well, but here's a 1971 Duster parts car in my backyard, I can't swear that it's correct but it looks like original parts and it runs, drives, stops normally, it is a power drum brake car but since the fender tag is not coded for power brakes I can only assume the booster was added.

And here is one on my 1970 parts car, also runs, drives, and brakes just fine. It's manual drum brake car (with the correct drum style 50/50 MC)

I think it was probably replaced at some point with the wrong master cylinder. I'm sure it stops fine I dont think the extra volume of fluid would effect the way the drum brakes work.



I myself had a 69 Dart that was converted to front disc and I ran the drum brake master for a few years. It stopped good you just had to step on the pedal harder than normal.

Picture 3 on yellow car is correct I have a original one at home and I have had car bought new Manuel disc brakes 1970 Duster 340 Changed master once and kept original

Drum all around,possibly something to do with the 71 Canadian built Darts .

Paul, could you post a few pictures of the original you kept?

Bill, here's the fender tag to the power drum car I posted the pic of (it's orange now but originally a bare bones white car, blue interior, column auto slant 6, Los Angeles plant).

Here we go! I found some long lost pictures that might clear things up. This is a survivor 1971 Dart, manual disc brakes with a good fender tag and broadcast sheet.

2

Car

So the question. Where is the best source for the correct MC, one that does the job and looks correct?

Should be the part number ending in 621. One inch bore. Worked for power and manual front disk brakes. It's often referred to as the Hemi MC. Are you looking for one?

Swap meet I guess, a lot of the aftermarket ones have a small round recess in the front snout . I have a original MC for a manual drum for my 71 demon last time I checked the kit for it was available at Napa for around $35. I'd have to dig it out but it has numbers on the underside that jive with the SM, # 3461189

Went back in my E-mails and here's what I found out.

67-68 used the MC 2225541. Had a 1" bore. Was used on both power and manual disc brakes. The MC lid had 70R3 stamping.

69-70 used MC 2229171 and 2229191 which was used on the Hemi cars. The lid had a stamping of J1703

It's my understanding that the 2229171 was used on all disc brake cars through 1975.

Also 70-71 Cuda/Challanger used 294444476 and 477.

Of course we all know the assembly workers used whatever part was available on a given day.

Find an original and rebuild it ?

I bought one about 13 yrs ago from Bill Rolik , he had some NOS ones, including the rod to the brake pedal, I put it in a friends 67 barracuda that he converted to discs ... wish I bought more than one ...