Tools You'll Need:
* Brake fluid: Use DOT 3 brake fluid. Make sure it's fresh and clean.
* Wrench: The correct size to fit the bleeder valve (usually 8mm or 10mm). A line wrench is ideal to avoid rounding the bleeder valve.
* Clear tubing: About 18-24 inches long, to fit over the bleeder valve and into a container to catch the fluid.
* Container: To collect the old brake fluid. A jar or small bottle works well.
* Socket wrench and ratchet (optional but recommended): To make bleeding easier and faster.
* Gloves: Brake fluid is corrosive.
* Clean rags or paper towels: To clean up any spills.
* A helper: To pump the brake pedal.
Bleeding Procedure:
1. Locate Bleeder Valves: The bleeder valves are located on top of each brake caliper (front) and on the wheel cylinders (rear). You will bleed each wheel one at a time, following the sequence outlined below.
2. Prepare the System: Have your helper sit in the driver's seat and have them pump the brake pedal a few times to build up some pressure. Ensure the master cylinder brake fluid reservoir is topped off with fresh DOT 3 fluid.
3. Bleeding Sequence: The correct bleeding sequence is generally Rear Passenger, Rear Driver, Front Passenger, Front Driver. This is important to ensure even bleeding of the system. Following this order helps push air out of the farthest points first.
4. Bleeding a Single Wheel:
* Attach the tubing: Place one end of the clear tubing securely over the bleeder valve, and submerge the other end in the container filled with brake fluid.
* Open the Bleeder Valve: Your helper should slowly and steadily pump the brake pedal several times. While they are doing this, carefully loosen the bleeder valve about 1/2 to 3/4 turn with your wrench. This lets air out and allows fluid to flow through the tubing into your container.
* Tighten the Bleeder Valve: Once your helper releases the brake pedal, tighten the bleeder valve before they pump again.
* Repeat: Repeat this process several times for each wheel until you see a steady stream of clear fluid without air bubbles coming through the tubing. Top off the master cylinder reservoir as needed.
5. Check Fluid Level: Keep an eye on the master cylinder fluid reservoir and refill it frequently. Never let it run low, as this can introduce air back into the system.
6. Test the Brakes: Once all wheels are bled, have your helper carefully pump the brakes a few times to ensure the pedal is firm and responsive. Test the brakes gently in a safe location before driving the vehicle.
Important Considerations:
* ABS System: The 1987 Mark VII *might* have an Anti-lock Braking System (ABS). If so, bleeding the brakes is more complex and may require a specialized tool or a scan tool to properly bleed the ABS module. If you suspect your car has ABS, consult a professional.
* Power Booster: If you are experiencing brake problems or if the brake pedal feels spongy after bleeding, there might be an issue with the power brake booster. This is a more involved repair that requires professional attention.
If you're uncomfortable performing this task yourself, take your vehicle to a qualified mechanic. Brake bleeding is crucial for safe driving, and improperly bled brakes can be dangerous. Incorrect bleeding can lead to a soft brake pedal, resulting in reduced braking ability.
