Jaguar Repair: Brake problem, cylinder problem, bleeder valve

Question
First of all thanks for the help.

I have a 1967 E-type that has a strange brake problem. At start up braking is normal. After driving for 15 to 20 minutes or so the brakes begin to "apply themselves" That is the pads gradually apply more and more pressure on the rotors until the car wants to stop. The brakes then get overheated and the car must be pulled over. The problem goes away when the engine is shut off and the car sits for a bit -- not sure how long this takes but it is OK by the time the brakes cool down. I am thinking it is related to the power assist.

THanks again -- Tim Bolling

Answer
Hi Tim,
You need to run the car until the brakes are dragging and quickly jack up one front wheel with the engine running and confirm that the brakes are dragging and open a bleeder valve to see if the brakes release. If so it is master cylinder problem most likely or something causing the brake pedal to not return.
When the brakes are not applied, there is an open and free flow of fluid from all the calipers to the reservoir. Something in your system (if it releases when you open the bleeder) has the fluid blocked off. Also check the valve that controls the booster.
What kind of fluid are you using?
Let me know,
Howard