E-Type brakes, holding on for dear life

I’ve owned my E-Type for over 5 years now.   During my ownership there has been one issue that has consistently plagued the car – brakes that do not release when they should.   Over my ownership I have replaced pretty much the entire braking system, and some components twice!

A couple of months ago, I had the master cylinder and booster replaced.   At first, I thought this had fixed the problem as the very uneven pedal pressure was gone.   However, sure enough after a couple of more sustained uses of the brakes, the non-release problem was back.

This time, I suspect the rears.   The rear callipers are pretty much now the only part of the brakes that has not either been replaced or rebuilt.   In addition, when trying to reverse the car it felt like it was fighting to get the rear axle moving.    My car does not have original rear brakes, the callipers have been replaced with XJ6 units, a useful upgrade.

Oddly enough, the brake lights were lit up even with the brakes not applied.   What started out as an enjoyable short drive in the car soured a little bit as I had to wait about 20 minutes for the brakes to release enough to move the car.     I also noticed I had forgotten to put the rear plate on the car.   At least it was a short drive!

Some cars seem to have an ongoing gremlin that is not fixed despite many attempts.   My 450SLC is similar with its perennially leaking transmission.    Sure enough, when moving the SLC out of the way to use the Jag, a red pool was visible where the car was parked.     I really would like to get to the bottom of this braking problem on the E-Type.  I have not had a good drive in the car since May 2016.