Here's a general outline of the process. Specific steps and procedures may vary slightly depending on your Lumina's engine and trim level. Always consult a repair manual specific to your 1995 Chevy Lumina for detailed instructions and diagrams. A Haynes or Chilton manual is a good investment for this type of work.
1. Safety First:
* Disconnect the negative battery terminal. This is essential to prevent accidental electrical shorts.
* Gather your tools: You'll need a socket set (metric), wrenches, screwdrivers (Phillips and flathead), a vacuum pump (to test the new booster), possibly a brake bleeder kit, and potentially a helper.
* Work in a well-ventilated area. Brake fluid is corrosive.
* Wear safety glasses and gloves.
2. Preparation:
* Drain some brake fluid: Open the bleeder valve on one of the brake calipers to relieve pressure in the system before disconnecting brake lines. Have a container ready to catch the fluid.
* Remove the master cylinder reservoir cap. This will help prevent spillage.
3. Accessing the Brake Booster:
* This is where the specifics vary greatly by Lumina model. You'll likely need to remove parts like the air intake system, possibly the windshield wiper motor, and possibly the master cylinder to gain access to the brake booster. Refer to your repair manual for the exact steps. Expect lots of bolts, nuts, and potentially some vacuum lines.
4. Disconnecting the Brake Booster:
* Disconnect the vacuum line(s) from the booster. Note their placement for correct reassembly.
* Disconnect the push rod from the master cylinder. This is the metal rod connecting the booster to the master cylinder.
* Disconnect the brake lines from the master cylinder. This is crucial – you might need to use a flare nut wrench to avoid damaging the lines. Be prepared for brake fluid leakage.
* Unbolt the brake booster from the firewall. There will be several bolts securing it.
5. Installation of the New Brake Booster:
* Install the new brake booster in reverse order of removal. Ensure that it's securely bolted to the firewall.
* Reconnect the push rod to the master cylinder. Make sure the rod is properly aligned.
* Reconnect the brake lines to the master cylinder. Tighten them securely.
* Reconnect the vacuum line(s) to the booster.
* Reconnect the master cylinder reservoir cap.
6. Bleeding the Brakes:
* Bleed the brakes thoroughly. This is crucial to remove air from the brake lines. Use a brake bleeder kit and have a helper to pump the brake pedal. Bleed each wheel one by one, starting with the furthest wheel from the master cylinder.
* Check for leaks: Inspect all connections for leaks after bleeding.
7. Testing:
* Use a vacuum pump to test the new brake booster. The repair manual will specify the proper vacuum readings.
* Test drive the vehicle: Check the brake performance carefully before driving normally.
Important Considerations:
* Master Cylinder: If the master cylinder is damaged or leaking, you'll likely need to replace it as well.
* Vacuum Leaks: A vacuum leak anywhere in the system will significantly affect braking performance.
* Brake Fluid: Use the correct type of brake fluid for your vehicle.
Remember, this is a simplified overview. Always consult a repair manual specific to your 1995 Chevy Lumina for detailed, step-by-step instructions and diagrams before attempting this repair. If you are unsure about any step, seek professional help from a qualified mechanic. Improper brake repair can be extremely dangerous.
