WOW.

after searching this forum about master cylinders and cap colors, and looking through close to 600 finds on my search, I've drawn this conclusion.

Chrysler never made a vehicle with manual brakes,
Chrysler never made a vehicle with drum brakes,
Chrysler never made a vehicle after 1971





now to my question,

I'm restoring my 72 340 Challenger. it's got manual 10" drum brakes. I think I kind of figured out that drum brake master cylinders were left natural and weren't painted. at least that's what I've read on cars built up through 71. I couldn't find anything about 72 and up cars and I couldn't find anything on the cap color and the clip that holds the cap on.

was the cap and clip painted or plated?

and was the MC painted or natural?


If anyone has some info for me, i would much appreciate it.


thanks, Greg

I'm not a 100% certain on a '72

But a drum master is usually unpainted, the cap is gold cad (some look kinda like gold zinc), The top bracket and hold-down bolt are zinc phosphate.

I've seen a number of NOS examples that were painted or coated (cap and body) with a dull gray gunmetal-like finish. I'd almost call it a parkerizing or gray phosphate.

I've seen a lot of rebuilts that have this same gray finish.
I've had a few NOS '71-'74 power disc ones that had this phosphate finish too. I've seen a couple "newer" ones that had gold cad plated caps, these were ones made as replacement parts in the late 70's or early 80's though so that doesn't tell us about what they looked like when the cars were being built.
It is my opinion that they started using this finish starting with the '71 model year both for drum and disc. The only exception I know of for sure is the hemi disc brake master cylinder which was a carryover from the '70 model year and was still painted black.
Just to confuse the issue though, the few NOS '71-'74 B and E body manual disc brake master cylinders I've had a chance to look at (part number 3580184 with casting number 2229271), were painted black.
The juries still out I guess.

thanks for the input guys,

i'm more confused now than before, LOL


i guess as long as i get the body the right color i have 90% of the battle won.


so i guess i'll keep a painted cap & clip and a plated cap & clip and ask the judges which one is correct to them

None of those pics are Mopar drum brake masters - Unless they changed the design after 71.

I didn't know you could still get front drums on a 72. My 73 Rallye is disc.

Sorry - I meant up to 1970 on the drum brake master and am guilty of being lazy and not reading - didn't realize there were 2 questions on the go. Please forgive me and I promise to read deeper!

Heres one i picked up a few weeks ago a #3461184 for my 71 demon. no traces of grey paint or coating, under the rubber cap seal its a gold anodize, but top has no trace, wire looks natural. BTW Brad what is the best way to store this master until i use it maybe several years from now when the car gets restored, Pumped new fluid through it and the piston moves freely, should i drain it, take it apart, and coat it with oil? Kits are still at Napa, autozone ect.. Thanks

one more

Howdy Mike
Are you sure that is NOS and not rebuilt? Those protective plugs in the outlets are not the style that Bendix used on their new manufactured master cylinders.
If you haven't had it apart, do not take it apart. The factory assembly lube is about as good a protective as your going to find.
Otherwise, what ever you do, absolutely under no circumstances even think of using any petroleum based oil in a hydraulic brake part!!! (unless its from a Rolls Royce or an airplane, they use a petroleum based hydraulic fluid).
Petroleum based fluids will destroy any EPDM or SBR rubber component internally on that part, and the cap diaphram.
I've coated the bore and reservoir of master cylinders I've restored with DOT 5 silicon brake fluid and sprayed the outer bare metal surfaces with WD40 to prevent corrosion.
Hope your work schedule allows you to make it to Rolling Meadows some Friday for the cruise, big turnout back at the old abandoned Dominicks site with lots of interesting cars!

i installed the caps i had laying around just to keep the fluid in and air out, it's not NOS but i think a used original, i have fridays off starting next week, and will be at mopars at the park. hope to see you.

Was 72 the last year for front drums on an E-body then?