These old brakes are news to me

Im working a 1962 jaguar Mark X definitely a first for my personal resume. Now im a young guy these archaic systems are far beyond but im willing to learn. I finally got this car running and im tryin to decipher exactly how this brake system functions my pedal goes straight down which moves the arm in the pedal box but the connection to the “diaphram” (or is it a booster…) doesn’t move at all.

You have whats known as a Kelsey-Hayes brake booster, it has dual master cylinders

As I understand it, this is the same brake system as early E-types, and you will find a good deal of info searching that forum, or Google, to find out how it works, sources of parts etc etc

That system is also on early MKX 1961-64, and I strongly advise you to obtain a copy of the Service and Parts Manual for that model if you are working on it

It is/was possible to get a CD off Ebay for less than $10

On any vehicle of that age, unless it is proven the brakes seals are 10yrs old or less, it will normally require the brake system to be dismantled item by item, and the seals renewed,

On my 420G, and other older vehicles, I had all items sleeved in SS. I would expect you will need the same

It is absolutely critical the brake system is in good working order

replace all 3 rubber brake hoses without question (unless <10yrs old)

I seem to recall that mid to late '50s Chryslers used these bellows type boosters. Google 1957 Chrysler engine compartment for some views. Probably were not dual circuit type though.

Hello, this system work like that of E type 3.8L.
You can repair with something other than the original master brake;
buy two master cylinders from Formula.
In France Formula 3 or Formula Renault EU, maybe Formula Ford in USA ?.
Two 5/8 ( 0.625 ) aloy cylinders new, exactly like the original 5/8 !.
After …good luck for stop 2 Tons !.