‘72 brake warning light

[Speedbird73]

Just picked my Bug up from getting some work done to the heater channels and front frame stub. It sat for 8 months. When I picked it up the brakes were very bad. I did some bleeding and couldn’t get them any better, so threw in a new master cylinder. Brakes still aren’t “great” but much better than they were. Tonight on a short ride while going down a hill I heard a small “snap” noise, and the brake warning light came on (only momentarily whenever the brake pedal is first released). This continued all the way home. Since I’ve owned the big (8 years) I have rewired it. I have never seen that light come on before other than with the ignition on and engine off. From what I see online most of them don’t actually work. Any ideas?

[Bobs67vwagen]

Check for leaks at each wheel and around all the flex lines and check fluid level in master cylinder.

[Speedbird73]

Checked each wheel (fronts are discs) no signs of fluid leaking from the wheel cylinders or calipers. All lines are dry and no puddles except that the lines to the master cylinder are wet. Will take it apart tomorrow to see if it is a cracked line or reservoir.....

[vamram]

Check for leaking switches at the MC. If one of them has failed, this will cause the warning bulb to light up. If you're having to pump the brakes for the light to go off, you may have a leaky switch on the MC. This has happened to me.
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[ashman40]

The two (2) brake switches with three (3) prongs each work on the idea that when both switches turn ON at the same time/same pressure they BOTH send power to the rear brake lights and do not send power to the Brake Warning Lamp. But when only one brake (pressure) switch is activated the inactive switch will pass current from the rear brake light circuit to the warning lamp ciruit to turn the Brake Warning Lamp ON. So if one of your brake switches is lagging behind the other (ON or OFF) it would turn the Brake Warning lamp ON momentarily when you press or release the pedal.

I agree this sounds like one of the MC switches has failed internally. Remove the rubber boots protecting the switch terminals and check for any moisture in the boot or on the switches. This is a common failure point.
If your switches are more than a few years old you should probably replace both with good NOS quality switches or the best quality switch you can find.
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[Speedbird73]

I will be in the market for brake light switches I suppose since they look very old, and haven't been replaced since I have had the car. Either way, I have always struggled with bleeding these brakes. I ended up jacking the rear as high as I could and letting it gravity bleed. Followed that up with doing the same for the fronts. Took it on a ride last night after completing this and No warning on the brake light. Looks like it may be solved for now.