Methods (in order of increasing complexity and effectiveness):
1. Gravity Bleed (Least Effective, Likely to Fail): This method is rarely successful on ABS systems due to the ABS module. It involves opening each bleeder valve one by one, letting brake fluid slowly drain out due to gravity. This method is highly unlikely to remove all air from the system and should be avoided.
2. Two-Person Manual Bleed (Slightly Better, Still Risky): One person pumps the brake pedal while the other opens and closes the bleeder valves. The order is generally: Rear passenger side, rear driver side, front passenger side, front driver side. However, this *might* not be sufficient for a complete bleed with an ABS system.
3. Pressure Bleeder (Recommended): This is the preferred method. A pressure bleeder connects to the master cylinder and maintains consistent pressure, forcing fluid through the system and expelling air more effectively than manual methods. Follow the specific instructions for your pressure bleeder. You'll still need to open each bleeder valve in the correct order (usually the same as the manual bleed, but check your repair manual).
4. Professional Scan Tool Assisted Bleed (Most Effective): Some advanced scan tools can command the ABS module to activate the pump and valves, cycling the fluid through the system under controlled conditions. This ensures a complete bleed, addressing potential air traps within the ABS module itself. This is the most reliable method but requires specialized tools and knowledge. A qualified mechanic is best equipped for this.
Important Considerations:
* Order: The bleeding order matters significantly. While the common order is rear passenger, rear driver, front passenger, front driver, *always consult a repair manual specific to your 1999 Ford Explorer 2WD.* Incorrect order can lead to incomplete bleeding.
* Fluid: Use the correct type and DOT rating of brake fluid specified for your vehicle. Mixing different types can cause problems.
* Reservoir: Keep the master cylinder reservoir topped off during the bleeding process.
* ABS Module: Air trapped in the ABS module is the most likely reason a simple bleed fails. A pressure bleeder *might* remove it, but a scan tool is more reliable.
* Repair Manual: A Haynes or Chilton repair manual for your specific vehicle is invaluable. It will provide diagrams, bleeding procedures, and torque specifications.
If you're not comfortable working with brake systems, it's best to take your vehicle to a qualified mechanic. Improperly bled brakes are extremely dangerous.
