Soooo nobody responded to my questions on changing an xke brakes to a more modern master cylinder ?? Well I did it myself, I was tired of having 3 reservoirs beside my exhaust pipes, I didn't like the big inefficient 8" master cylinder in a hard to get at location, or the separate master cylinder to activate it, nor did I see a need for a vacuum tank to supply the booster ??

I purchased a modern 1" bore dual master cylinder with built in reservoirs and a efficient 7" booster attached which comes with its own check valve. This MC has sealed fluid containment so requires no fluid level monitoring and is suitable for many aftermarket builders. I fabricated 1 1/2" square tube bracket to fit the front of the xke footbox (see construction drawing). I mounted the booster on a 1/4" thick plate and ran a small support bracket back to the firewall. Using the original pedal arrangement I put a 3/8" NF grade 8 rod on the Jag brake pedal with 3/8" hemi joint on a bar to change the direction of force to the new master cylinder. All this sits where the old brake bellows were on a 3.8 xke. I first tried to put this new setup in line with the original but it would not fit between the frame rails, so it had to go above and against the firewall. This placement gets the fluid reservoirs away from the exhaust heat!. The pictures show the early xke bellows mount, my mockup for fitting on my 1970 E-Type, the fabrication of the tube mount and the final installation.
By keeping the fulcrum bar equal distance between the pedal rod and the MC rod you can take full advantage of the Jag built-in 6 to 1 pedal ratio.
I have built over 38 cars before and often used this setup when stuck for brake component space. You will notice I used a 3/4" clutch master cylinder also with a built in reservoir. Let me know what you think.

 

Now this is some great work. Thanks for sharing.

 

thanks for showing this fabrication. It is certainly an option to consider if the original Jag brake bits go bad.