1. Bleeding Procedure Verification:
* Thorough Bleeding: Did you bleed all four wheels thoroughly? Air bubbles can easily hide in the lines. It's often necessary to bleed multiple times, ensuring a firm pedal each time. Consider using a pressure bleeder for a more effective bleed. Proper sequence is important - usually starting with the furthest wheel from the master cylinder.
* Proper Technique: Ensure you're using the correct bleeding technique for your vehicle. A helper is usually necessary to pump the brake pedal.
* Bleeding System Check: Check for any leaks in the brake lines, hoses, or at the connections. Even a small leak can prevent building pressure. Use soapy water to check for bubbles.
2. Master Cylinder Installation:
* Correct Installation: Double-check that the master cylinder was installed correctly. Any misalignment or incorrect fitting can affect its operation. Refer to a repair manual for precise installation instructions.
* Master Cylinder Functionality: The new master cylinder itself might be faulty. Although less likely, it's possible to receive a defective part.
3. Other Brake System Components:
* Brake Booster: The brake booster assists the master cylinder. A faulty booster can result in a weak or unresponsive pedal. You can sometimes test this by feeling for assistance when depressing the pedal. If it feels extremely hard, the booster may be at fault.
* Proportioning Valve: The proportioning valve regulates braking force between the front and rear brakes. A malfunctioning valve can lead to uneven braking or brake failure.
* ABS System (if equipped): If your Taurus has an Anti-lock Braking System (ABS), there might be an issue within the ABS module or its associated components. This often requires a diagnostic scanner to check for codes.
* Brake Lines and Hoses: Examine the brake lines and hoses for kinks, cracks, or significant wear. Internal corrosion can also restrict flow, even if there are no visible external problems.
* Wheel Cylinders (Rear) or Calipers (Front): These components are responsible for applying the brakes to the wheels. A seized caliper piston or a leaking wheel cylinder would prevent pressure build-up.
* Brake Shoes or Pads: While unlikely to cause complete failure, severely worn pads or shoes can affect brake performance.
4. Professional Assistance:
If you've checked all the above and still have no brakes, it's crucial to seek professional help immediately. Attempting to drive a vehicle without brakes is extremely dangerous. A qualified mechanic will have the tools and expertise to diagnose the problem accurately.
Important Safety Note: Do not attempt to drive the vehicle until the braking system is fully functional. This is a serious safety concern.
