My daughters car is a 1999 Saturn SC2. My mechanic says the brake pads/caliper, etc. are fine, but the pedal is very soft. What could be the cause? I checked the brake fluid and it is not low. The car stops/slows fine.
IF the brake pedal feels "spongy" there may be air in the brake system. You can address that by bleeding the brake system. There is a diaphragm inside the master cylinder as well, it may have a slight crack and cause the air to enter the system as well. I would start with a typical brake bleed to see if it "firms" the pedal up.