so i bought an 89 2500 today. when i step on the brakes there is this weird noise that comes from down where the pedal is it almost sounds like static or air pressure being released. this sound continues until i let off the brake. the brake also feels really stiff and i really have to step on the peddal to get it to slow down or stop and stay stopped. i noticed the truck has a brake controller a: Sentinela Tekonsha this is what it says on it, it has two adjustments and 1 led light the adjustment on the left is a wheel adjustmen and says "gain" the led light turns from red to green at a certain point when i mess with this adjustment the other adjustment is a knob adjustment and says "level" it spins endlessly to the left or right and doesnt affect the led. also on the bottom of the brake controller on the right side there is a part that slides to the left and is spring loaded to return to the original position. can any body tell me whats wrong with my brakes. i added brake fluid to the resivor as it was almost empty i am thinking maybe i need to bleed the brakes but at the same time not as a brake pedal usually feels really loose when they need to be bled.