Our 2002 Kia Spectra recently started making a creaking noise when braking at low - medium speeds (such as slowing down to a stop sign). The creaking noise sounds like a creaky spring on an old mattress or like croaking. The noise only happens when the brakes are depressed with a medium pressure. Very light pressure or hard pressure do not cause sounds. Also, the noise is significantly louder when the weather is warmer. It seems like the noise gets louder when the car has been driven longer as well. It only happens when the car is moving forward, not in reverse.
We've had the brakes replaced by one mechanic. Another mechanic took apart the brakes and found no problems and put it back together.
We're hoping to sell the car very soon, but think the sound needs to be fixed before we can put it up for sale. We read a Yahoo post by someone with a similar problem. An answer submitted was to grease the front axle shaft splines. We're not sure if the solution is the same for our car. Any help/advice would be appreciated very much.