Techie question ... (Jeep)

[Mike Cecil]

Gents,

I'm consulting the brains trust, please ...

Willys MB:

New master cylinder installed about 2 years ago (about 1,000 miles ago). Everything working fine. The cheap no-name brand brake switch started needing more and more foot pedal to make the brake light work, so this morning I:
(1) removed the switch
(2) inserted a name brand switch
(3) bled the brakes.
(4) went for a short drive.

Problem: brake light remained on after the first push of the pedal. Checked the electrical circuit and the brake switch was live across the two terminals even when the brake was not depressed.

Solution: replace the new switch with another new switch from stock. The first switch removed, once out of the vehicle, was no longer live across the terminals once, so the problem was not the switch.

Problem: New replacement switch is like the first one: the brake lamp stays on after first application, but now turns off again by itself after about 45 seconds to 1 minute.

Anyone have any thoughts about what I'm doing wrong? Brakes are working fine and are not remaining on once the pedal is no longer depressed. I bled the brakes using a pressure bleeder, which leaves the master cylinder very full: is that the problem?


Mike