Technical Brake cylinder fitting

Does anyone know what kind of fitting goes in here? It’s a 1960 Cadillac rear end, threads are 7/16-20. When I look in there it’s like a funnel shape, not a volcano….

thank you

 

Not a fitting but style of brake line flare,,
Google ISO bubble fitting ID. And tube nut to suit.
May be called something different over your way.

 

looks like it takes a bubble flare. It's probably not original...

 

One on the right

 

All these years and never heard it described correctly as a bubble flare.
And DIN,in my world that’s metric

 

If the thread is 7/16-20, then it's NOT a DIN fitting. Probably takes a normal US thread nut, and just don't do the last step of making a double flare.

 

Weird... inverse flare is 7/16-24 or 1/2-20.
My 1964 Cadillac used 1/2-20 conventional inverse flare.

 

Ah. Thank you. I’ll give the bubble flare a shot. Much appreciated.

 

Double check the tube nut thread, measure once and all that.

 

The plot thickens... I found a pic on ebay of 1960 Cadillac cylinders. One shows a copper washer and one shows sometype of copper fitting down in the hole. I just don't get it.

 

In the picture of the two side by side, that copper / br*** seat in the hole is a seat for an inverted flare.
If I was you I would go to a real live parts store and see what they have or can get. I suspect the right wheel cylinders will accept a normal inverted flare (double flare).

 

1960 Cadillac had a flex hose from the rear wheel cylinders to the frame, both sides, then to a steel line.
Go to Caddydaddy.com and look up the wheel cylinders and hose.

Bill