* Glazed brake pads: Overheating can glaze the friction material on your brake pads, making them less effective and more prone to squealing.
* Worn brake pads: Thin pads can vibrate against the rotor, causing noise.
* Dirty or contaminated brake rotors: Rust, dirt, or grease on the rotor surface can interfere with pad contact and lead to squealing.
* Brake pad wear indicators: These are small metal tabs embedded in the brake pads that scrape against the rotor when the pads are worn down to their minimum thickness. This is a warning sign that your pads need replacing.
* Loose or damaged hardware: Loose caliper bolts, guide pins, or anti-rattle clips can allow the brake pads to move and create noise.
* Improperly installed brake pads: If the pads weren't installed correctly during a brake job, they might not be contacting the rotor evenly.
Here's how to troubleshoot and potentially fix the problem:
1. Check Brake Pad Wear:
* Visually inspect your brake pads: Jack up the car (safely!), secure it on jack stands, and remove the wheels. Look at the thickness of your brake pads. Compare them to the minimum thickness specified in your owner's manual or look up a replacement pad for your model to see the wear indicators. If they're worn, they need replacement.
2. Inspect Brake Rotors:
* Check for rust, grooves, or scoring: Significant rust or damage needs to be addressed. Lightly sanding minor surface rust might help, but significantly warped or damaged rotors require replacement.
3. Clean the Brake Components:
* Clean the rotors with a wire brush or brake cleaner: This will remove any dirt, grease, or rust. Make sure to clean the caliper guide pins and thoroughly wipe everything down with a clean rag. Brake cleaner evaporates quickly, so be careful not to breathe it in.
4. Check Caliper Guide Pins and Hardware:
* Inspect the guide pins for rust or binding: If they're stuck or rusty, they need to be cleaned, lubricated (with a specialized caliper pin lubricant, *not* general-purpose grease), and possibly replaced. Also, check all bolts to ensure they're tight.
5. Consider Anti-Squeal Shims:
* Inspect your brake pads for anti-squeal shims: These are thin metal plates that help reduce vibration and noise. If they're missing, damaged, or incorrectly installed, this could be the cause of the squeal. Replace or re-install if necessary. New brake pads typically come with these.
6. Addressing the Problem:
* If the pads are worn: Replace them with new ones. This is the most likely cause.
* If the rotors are damaged: They'll likely need to be resurfaced (machined) or replaced. Resurfacing is usually cheaper, but if the damage is severe, replacement is necessary.
* If the squeal persists after cleaning and lubricating: You might need to take your Alero to a qualified mechanic for further diagnosis. They have specialized tools and expertise to identify and fix more complex brake issues.
Important Safety Note: Working on brakes requires a basic understanding of automotive mechanics and safety precautions. If you're not comfortable working on your brakes yourself, take your car to a professional mechanic. Improper brake repair can be very dangerous. Always use jack stands to support the vehicle, never rely solely on a jack.
