1. Penetration and Grip:
* Penetrating Oil: This is your first and best line of defense. Liberally apply a penetrating oil like PB Blaster, Kroil, or Liquid Wrench. Let it soak for several hours, or even overnight. Reapply as needed. Heat can help the oil penetrate better (see below).
* Vice Grips/Slip-Joint Pliers: After penetrating oil, try gripping the screw with vice grips or slip-joint pliers as close to the head as possible. Apply firm, steady pressure while turning counter-clockwise. Avoid excessive force, which could damage the brake fitting.
* Extra Grip: If the head is severely corroded, try wrapping the jaws of your pliers with a piece of rubber (a short piece of rubber hose works well) to improve grip.
2. Heat:
* Heat Gun: Carefully apply heat from a heat gun to the bleeder screw. This helps expand the metal and break down corrosion. Be extremely cautious! You don't want to overheat the brake cylinder or surrounding components. Keep the heat gun moving and monitor the temperature.
* Torch (with extreme caution): A propane torch can be used as a last resort, but this is risky. You can easily damage the brake components, and the heat can cause the brake fluid to boil. Only attempt this if you're very experienced and understand the risks.
3. Drilling and Extraction:
* Drilling a pilot hole: If the screw is completely stripped, carefully drill a pilot hole in the center of the bleeder screw head using a small drill bit. This allows you to use a screw extractor (see below). Drill slowly and carefully to avoid damaging the brake line.
* Screw Extractor: Once a pilot hole is drilled, use a screw extractor (also called an easy-out) the appropriate size. These are specialized tools designed to remove broken screws. Follow the instructions carefully. This method can be very effective, but if done incorrectly, it can further damage the bleeder fitting, requiring more drastic measures.
4. Last Resort: Cutting and Replacing
* Cutting the Bleeder: If all else fails, you may need to cut the bleeder screw off with a tubing cutter or Dremel tool. This usually requires a high degree of precision to avoid damaging the brake line. Once cut, you'll need to use a flare nut wrench to remove the remaining threaded piece from the brake caliper.
* Replace the Bleeder: After removing the old bleeder screw (however you accomplish it), replace it with a new one.
Important Considerations:
* Safety First: Always wear safety glasses. Brake fluid is corrosive and can damage your skin and eyes. Use caution when working with heat and sharp tools.
* Brake Fluid: Be prepared for some brake fluid leakage. Have rags ready to absorb any spills.
* Professional Help: If you're not comfortable with any of these methods, take your vehicle to a qualified mechanic. This is especially true if you're working on the rear brakes. A damaged rear brake system can be dangerous.
Remember to properly bleed your brakes after replacing a bleeder screw. If you're not familiar with this process, consult a repair manual or seek professional assistance.
