Here's a breakdown of the process and considerations:
1. Safety First:
* This is crucial. Failing brakes can be fatal. If you're unsure about any step, do not proceed. Get help from a qualified mechanic.
* Vehicle Safety: Use jack stands properly to support the vehicle. Never work under a car supported only by a jack.
* Bleeding the Brakes: You'll need to bleed the brakes after replacing the lines. This requires two people.
* Cleanliness: Keep everything clean to prevent debris from entering the brake system.
* Proper Tools: You'll need the right tools (see below).
2. Tools and Materials:
* New brake lines: Get the correct length and type from an auto parts store (mention year, make, model). You might need to bend them yourself (see below).
* Tube bender: Essential for creating the correct bends in the new lines. A hand-held bender is more practical for most home mechanics.
* Flare nut wrench set: This is critical for working on the brake line fittings without damaging them.
* Line wrenches: For loosening and tightening the brake line fittings.
* Double-flare tool: You'll likely need to create double-flared ends on the new brake lines to match the existing fittings.
* Brake fluid: DOT 3 or DOT 4, compatible with your car.
* Jack and jack stands: Absolutely necessary for safe working conditions.
* Wheel chocks: Essential for added safety.
* Wrench set: Various sizes for bolts and nuts you'll encounter.
* Socket set: Helpful for removing various components.
* Safety glasses: Protect your eyes.
* Gloves: Protect your hands from brake fluid and dirt.
* Rags: For cleaning up spills.
* Tube cutter: For cutting the old brake lines.
3. The Process (General Outline):
* Preparation: Disconnect the battery negative terminal. Raise and securely support the vehicle on jack stands. Remove the wheels where you're working on the brake lines.
* Removing Old Lines: Carefully loosen and remove the old brake lines, noting their routing and any bends. Take pictures if needed. Use the correct wrenches to avoid damaging the flare fittings.
* Bending New Lines: Carefully measure and bend the new lines to match the old ones. This is where a tube bender is essential. You'll need to create the same bends and angles as the originals.
* Connecting New Lines: Attach the new lines, using a flare nut wrench to carefully tighten the fittings. Do not overtighten.
* Bleeding the Brakes: This is absolutely vital. Use a brake bleeder kit to remove air from the brake lines. This requires two people – one to pump the brake pedal and one to open and close the bleeder valves.
* Testing: After bleeding, test the brakes thoroughly before driving. Pump the brakes several times, then check for leaks around the new fittings.
4. Important Considerations:
* Corrosion: Old brake lines are often corroded, making them difficult to remove. Use penetrating oil to help loosen them.
* Routing: Pay close attention to the routing of the original lines; correct placement is essential for proper function and to avoid interference with other parts.
* Leaks: Check for leaks *carefully* after reassembly. Any leaks must be fixed immediately.
* ABS: If your Lumina has Anti-lock Braking System (ABS), the process is more complex. You might need a scan tool to clear any ABS codes after work is completed. It may require professional servicing.
In Conclusion:
Replacing brake lines is a serious undertaking with significant safety implications. If you are not comfortable with any aspect of this process, or lack experience working on vehicles, take your car to a qualified mechanic. It's far safer and cheaper in the long run than risking brake failure. The cost of professional repair is small compared to the potential cost of an accident.
