I dont think it is the brakes or rotors causing the problem after reading up. Its like u almost gotta pump or slam the brakes to get it to stop and its really weak. The brake pedal feels different when pushing it in too. What do you think it is? This is a 94 4x4 explorer, what do you think this would cost also?
The pressure in the system is very high 2800 to 4800 psi, opening the maintenance bleed is going to give you a shower and the pressure release will cause bubbles to form. Unless you are having a problem (the ALB light is on) I would not mess with it, if you do what to work on it you need to get the service manual. I would just take it to the dealer and spend the $200 to have them flush it and replace the Fluid which is recommended maintenance every 2 years.
It does sound like you have some air in the system. Bleed the brakes while someone repeatedly applies pressure to the pedal, topping off the brake fluid resevoir, until you don't feel any more sponginess in the pedals, and the fuid comes out of the bleed valve in a continuous stream with no interruption.
If the problem has occurred without having performed any recent work, then replace the master cylinder. If you have recently replaced callipers or wheel cylinder, then bleed the brakes. Gravity bleeding is the easiest to do by yourself. 1. Fill Master Cylinder 2. Loosen the RR bleeder [may have to push the brake pedal to begin the process] 3. Allow to drip until no bubbles are visible 4. Move to RR FR FL 5. Constantly monitor the master cylinder level 6. Clean off brake fluid with brake cleaner or Methyl Hydrate Should cost no more than a $100
