DS master cylinder
 

Does anyone recognize this master?
I would like to know the original application so I can get one from NAPA.
It came from Detroit Speed a few years ago. It is iron.

Possibly late 80’s - early 90’s S-10?

G-body MCs had those angled reservoirs. But you can't go by the looks. You need to figure out the MC bore size.

Andrew

I know I need the bore size. Prolink does not search by bore size. I need to find the application, they list different bore sizes in that.

Master
 

Looks similar to S-10. I have one in my pantera
But two reservoirs that step. The bores on mine are also
stepped sizes . I have wilwwood winston cup brakes up front six piston and
4 piston wilwoods out back

Bob

Here you go:
 

All of these applications below when equipped with the diesel engine running factory installed hydroboost:

BUICK CENTURY 1981
BUICK REGAL 1981
BUICK RIVIERA 1979-1981
CADILLAC ELDORADO 1979-1981
CADILLAC SEVILLE 1980-1981
OLDSMOBILE CUTLASS 1979-1981
OLDSMOBILE CUTLASS CALAIS 1979-1984
OLDSMOBILE CUTLASS CRUISER 1980-1981
OLDSMOBILE CUTLASS SALON 1979-1980
OLDSMOBILE CUTLASS SUPREME 1979-1981
OLDSMOBILE TORONADO 1979-1981
PONTIAC GRAND LEMANS 1982-1983
PONTIAC GRAND PRIX 1981

Go hit RockAuto and pull up the application and it will give you an exact actual image (which I love about RockAuto). So many places use generic or similar images, but kudos to them as these guys have taken the time to show you the honest to goodness exact part that you are going to pull out of the box, which makes for an excellent visual library.

:cheers:

Thanks to Hydratech. It looks like the correct model, reservoir might be smaller but I can swap that.
I will never again order from Rock Auto, 5 times, all returns. They don't list their items properly. They are only an office, don't have any quality control.
I have received used parts, incorrect parts, body parts that were painted and damaged. I lost money on every return because they claimed not their fault.
I have a NAPA Prolink account, multiple pics, they deliver everyday and never have a return problem. I am set up with a pretty good price structure.

It is the right model...
 

I know it's the right model because it is a factory hydroboost spec MC, which I obviously have exceptional familiarity with. I had a '80 diesel Cadillac Eldorado 4 wheel disc factory equipped with hydroboost that ran this exact MC. I yanked the (junk) Type II internal accumulator model hydroboost unit out and swapped in the vastly superior external accumulator Type 1 model, recalling this MC in my hands very clearly while doing this. Looking at your picture, I do not believe you will have to swap out the reservoir - should be spot on - it is a 1" bore. Of course I also yanked the diesel Olds 350 out and swapped in an Olds 455 in its place. What a trip that was watching tire smoke billowing out of the front wheel wells - it would pour smoke right into the cabin real bad if you had the windows down LOL.

As far as RockAuto? I wasn't endorsing them, just mentioning that they have what I feel to be a nice quick reference visual when needed. I have found their images to be accurate in most all cases. I also use NAPA, as we have a MASSIVE NAPA distribution warehouse literally right behind us with a customer showroom and counter. What I have however found with NAPA online is that their images are not as accurate many times. I checked the application just now on NAPA's website and this application IS coming up, but with incorrect images. I just ran a Bing search for 1980 Cadillac Eldorado Master Cylinder and it produced a whole bunch of listings with the correct images.

See if your NAPA contacts can cross reference any of these:

ACDelco 18M95
Raybestos MC39079
Duralast NM1740
Centric 130.62036 (remove the dot in some lookups)
Dorman M101260

Or? Just order in from Summit Racing:

https://www.summitracing.com/parts/ado-18m95

https://www.summitracing.com/parts/agb-mc39079

:lateral: