I've been messing with the brakes lately - my prop valve was leaking and I've had it off a couple of times, and I finally replaced it with a different one (I think one from a 70). The brakes seem fine - the car stops just fine. I didn't bleed the brakes so its possible there's some air in the lines but the light didn't come on right away. I drove it quite a bit over the last week until today when it came on as I was tinkering with it in the garage, not driving just idling. I've had more air in the lines than this and the light never came on. Any ideas?

Andy

Nevermind. I was wrong.

The valve on the frame can set off the brake light. If it notices a difference in pressure from front or rear the valve will close one side off and the switch will ground to it. Follow the tan wire down to the valve and remove the connector, if the light goes out this is your problem.

That light is serves 2 purposes. 1 is to let you know the parking brake is on. 2 is to let you know you have a problem with the distribution block on the frame. If you had a bad brake line, usually the rear line, there is a pin within the block that shuts off the fluid to the rear so you don't completly lose the brakes.
Check the adjustment of the parking brake first. If it is loose, lift it with your hand and see if the light goes out. If it does, you need to adjust your parking brake. If that doesn't solve the problem, you have a problem in you brake system.

The brake warning light is triggered by 2 things.
1- setting the parking brake.
2- the pressure differential valve.If pressure is lower in one side of the valve it grounds the circuit and the brake light comes on.
:clonk:

That's what I thought. I was surprised to see it since it has never come on before, even with the PB on. Hmm, well that's a first - something spontaneously STARTS working on the car, instead of the other way round :confused:

heh heh. My PB is disconnected since the front end work. the pedal had been pushed down, and I just hit the brake release and pulled the pedal up and the light went off :clonk: I guess look at teh simple things first :clonk: :clonk: