2000 mercury cougar with a brake problem...please help!!

could be low of fluid, or your emergency brake switch

did you bleed all of the air from the master cylinder before you installed it, this has to be done. also when replacing the master cylinder, all 4 wheel cylinders will have to be bled, in order to get all of the air out of them. while doing the wheel cylinder bleeding , you will have to make sure that the master cylinder doe's not run out of brake fluid, check it each time you bleed a wheel cylinder , add brake fluid to the master cylinder each time or when it is getting low. hope that this has helped you.

1990 Mercury Cougar Bostonian, mint condition... recently purchased. I hear a whisting/slight high pitch noise that seems to be coming from, in back of the glove box. Any suggestions or ideas?

To start the car, the brake pedal must be depressed to activate the brake pedal switch. In my experience, adjusting the switch has not worked. If this switch is the problem, replacing the switch is the fix.

The indicator light is there to tell you your brakes are out of adjustment just remember that if you just replaced your brakes that your parking brake may need adjusted this will make the light stay on also.

Not likely! cause the length wouldn't be right or the way it mounts. You could use one off of another cougar within a couple years make of yours.

This video covers both replacement of disc an drum brakes. It should help you.
http://www.wonderhowto.com/how-to/video/how-to-replace-car-disc-brakes-and-drum-brakes-243973/

It is possible the wires going to the switch have shorted it is a common problems with ford and merc. cars around that time. You can follow the bar attatching the brake pedal to the car and up under the dash there will be a switch the bar hits on check the wires going to the plug if that is the problem the plug can be replaced. Hope that helps.

There is a Relay under the Hood in the Fuse Relay Box. Replace this and it should be OK. If not let me know so that we can look elsewhere for the Problem. Please Rate my Solution, I need all the Help that I can Get!

I replaced the ball joints and fixed the problem on mine.