BRAKE light is on, do I need to flush/bleed my brake fluid and refill with new?

Be Careful PLEASE! Using synthetic brake fluid in a non synthetic system is not advisable! It could destroy every piece of rubber in the system! Standard brake fluid is hydroscopic(it absorbs water), the synthetic is not! Best thing to do, is to get standard brake fluid dot 3 or 4. remove brake master cyl cap fill to max line, open all bleeders in the brake system till fluid runs out clean(gravity bleed).Do NOT let master run dry keep it topped off at all times. Once brake fluid is running clear from all bleeders close them one at a time starting with the one furthest from the master cyl(usually rt rear). Fill master cyl to max line. check your peddle. if it still feels spongy you will need to pressure bleed the system. To do this have a friend sit in the drivers sest and gently depress the brake peddle and hold making sure not to move their foot all the way to the bottom or back so no air gets in.open one the rt rear bleeder . fluid should shoot out. close bleeder while fluid is coming out.Have your friend pump the peddle and then depress again.(this will have to be repeated several times when ever you open and close the bleeder screw on the brake caliper) If air bubbles were in the fluid continue this step at the rt rear till all air bubbles are gone. repeat on the other three corners of the vehicle moving to the lft rear next then rt frt then lft frt .. Good Luck! Remember dont let the master go dry!

Also the red brake light only comes on for four reasons: #1 low fluid,#2 e-brake on,#3 massive hydraulic failure, and#4 bad switch?sensor(at mastercyl, or e-brake)