QuestionI changed out my battery- it was time to. Then it started making a scraping/grinding noise appeared to coming from the driver-front side(wheel area). It never made the noise at any particular time (whether the engine was cold or it had been running or miles). It would do it suddenly then stop. I initially though it to be a belt problem, took it to a mechanic and because I could not make it make the noise when someone else needs to hear it. He didn't know what the problem was. It was time to replace the belts so I had him do that. The noise never went away. Recently the noise has switched to the front passenger side (wheel area)and last longer than it did on the other side- much louder. My dash brake light is coming on- so I will check the brake fluid to remedy that. Could it be brake pads? I am truly at at loss. I never had any problems with this vehicle but since it is a month away of being fully paid off-it now wants to give me trouble. HELP?!
AnswerHi Kirsten,
Good to hear you're doing your regular maintenance!
Yes, it sounds like it could very well be your brake pads. Pads will often have a small, metal tab called a 'wear indicator' that will create a great ruckus to inform you that your pads are wearing thin. This is designed to do no harm to the discs. Should it be ignored, however, some damage may occur. A metal-on-metal scraping sound could be the metal mounting plate part of the pad scraping on the brake disc. When you brake, the fibrous material adhered to the metal plate wears slightly. Over time, that material may wear to nothing, exposing the mounting plate. This plate, and the rivets that secure the pad material, will wear grooves in the brake disc. If this is the case in your instance, you may need to have the discs 'turned', too.
'Turned' means to have the surface of the disc that comes in contact with the pads lathed as to make that surface smooth again. Installing new pads without turning scared discs could create a 'shimmy' when you apply your brakes. It's not overly detrimental but can cause premature wear on items like tie rod ends and ball joints.
Also, as your brakes wear, the pistons in the calipers, the component that squeezes the disc between your brake pads, protrudes farther out of the caliper due to the thinning of the pads. This protrusion leaves a larger space behind the piston, requiring more brake fluid to fill the space. This causes the brake fluid reservoir under the hood to go low. When the pads are changed with new, thicker pads, the pistons are reset to their original position in the caliper, displacing that fluid back into the reservoir. In that vein, I don't know that I'd add more fluid as the resetting of the pistons may cause an overflow. You may just want to have your pads changed as soon as possible.
The changing of pads and removal of discs for turning are generally an easy job. Some mechanics like to tell customers that their discs or 'rotors' need to be replaced when in actuality, they just need to be turned. They can mark up the price of a disc and make themselves a little more money that way. If you can't do it yourself, I suggest you get someone you trust to do it for you. If they say your discs need to be replaced, I'd suggest you have them prove it to you. The discs, by law, have to be of a certain thickness. Should they say the discs need to be replaced, they should be able to show you that your discs will be less than that thickness once turned.
As stated many times before, I suggest you get a manual on your vehicle. They're available at most parts stores, inexpensive and a wealth of information. Even if you don't do any of the work yourself, you'll be able to learn much about your vehicle, saving you money from ruthless mechanics.
Good Luck!
