E-Bodies.org Cuda Challenger Forum

I find it odd that you say your car has the "original" master cylinder, yet it has the wrong cap ? I wouldn't think just the cap would be an item that would be replaced ? Even at a rebuilders, I think it would be odd to replace the cap  :thinking:

So your just looking for the rubber gasket?
Maybe I'm not seeing it correctly, but wouldn't be seen under the lid?

Here's an image of my cap.  Based on Dave's reference guide it's an aftermarket.  Why only the cap would have been replaced is not clear.  Sure has plenty of patina.  Perhaps the gasket was leaking so a new cap with gasket was purchased at some point during it's life.  I'm speculating.

I would never question Dave Wise :worship: , but I think he would have to document a heck of a lot of 70 E Bodies with drum brakes that still have their original master cylinders to definitively say what is absolutely correct and what is not....How could he possibly confirm that it wasn't some sort of production run change made by the master cylinder manufacture ?  If their was part numbers or instruction information stamped on it, or some sort of identification to prove "aftermarket" vs "original" then I would say it would be obvious, but with the caps being very similar with only different styles of venting....I'm not so sure I would agree. JUST MY OPINION :alan2cents: 

In my research of master cylinders I saw a lot of that style drum brake part, but never paid close attention to the nuances of the lid.  I can say it was made by Bendix for '67-'70 model years at apparently multiple plants.  I've seen 3 different casting numbers on OE examples.  And Bendix continued to manufacture it as a replacement part well into the 80s.
It was used across the model lines on most drum brake cars during that era so literally millions were made, and there were some slight variations.
Also, the aftermarket companies like Wagner and Raybestos made service parts for these cars that didn't look like the original Bendix parts, they had bale wire retained caps like Dakotas picture.
So I don't know if any aftermarket company would have even sold that style cap.
In recent years, after everything moved to China, the aftermarket master cylinders do have a bolt on cap, but they look different.  One has to buy the PG repro to install on the recent aftermarket ones to make it look original.

The cap isn't OE, I can't tell about the casting from that picture but probably not OE either.

Ok was worth a shot. Good luck

What about this one?

Both the master and cap look to be originals.  If you remove the clamp you can confirm there are vent holes as shown in the posted Dave Wise image.

Thanks Kevin

For Reference here's an NOS master cylinder from my parts stash

In the original box never installed for 1970 models with 4-wheel drum brakes

Correct Bendix master cylinder with cast # 2225601 on bottom and Chrysler part #2808577 on box

Original lid - with hold down clamp in place and removed
Note lid has the vent holes

Another way to ID an original lid that Dave Wise does not point out in his guide. The originals have 2 square corners and 2 rounded corners opposite of each side

Very nice NOS master. It confirms the features and more. Very helpful. I noticed TheRamMan is reproducing caps. His appear to have all the correct features.

Ram man is probably selling the PG Classics cap.

Ah. Hadn't considered that.

I have this one.

No need to clean it. Let me know price.

the casting had a B59 "date" - I found no other date  :dunno:

I have these two power drum brake Bendix master cylinders that came off of 1969 B-bodies

one has the above mentioned "MADE IN CANADA" hold down bracket & appears to have "REMANUFACTURED BENDIX" or similar stamped on the side of the casting

the ODD thing is, both are missing the bolt that holds the "guts" in the master cylinder  :dunno:

anyone seen an  "AANF" cast unit without the bolt, possibly/assumedly for a power drum brake car??  :clueless:

The first one of these I ever had my hands on was a NOS sample at my old work and it had no retainer screw.  It was in a Bendix box, not a Mopar box. It's the one pictured in the Pumping Points article in Mopar Action.
It was a "newer" sample and my opinion was that late in production Bendix stopped using the screw as a cost reduction.  They manufactured these for approximately 20 years, starting in 1966 for the '67 model year through sometime in the mid to late 80s as replacement parts. Anything made for that long a time is going to have some minor engineering design changes take place over the years.
I had a used one with the pin instead of the bolt.  I suspect a commercial rebuilder reassembled them with a new pin instead of reusing the bolt,  I'm not sure how you'd rebuild one with the pin, it would be a challenge to get that pin out!
I didn't keep any copies of paperwork for the drum master cylinders from when different samples of these were analyzed at my old work like I did for the Mopar disc brake mcs.  I have some notes saying Mopar part numbers 2808577, 2808599 and 3420961 were all determined to be the same when the engineers analyzed them in the late 60s, but they were analyzing for fit and function not looking at any details that someone would be interested in for doing a concours restoration of a car 50 years later of course.

Looks like 2988?  That would be 299th day of '68 or '78

im interested what do you want for it? thanks for answering.
damon

I just had a really good experience having my 70 disk brake MC rebuilt at Brake Warehouse in Minneapolis and just today got my booster back from Booster Steve. Great people all around.