Here's a general outline of the process. Specific steps may vary slightly depending on the exact configuration of your van. Always consult a repair manual specific to your 1993 Chevy G20 for detailed instructions and diagrams.
Tools You'll Likely Need:
* Socket wrench set (metric)
* Wrenches (metric)
* Screwdrivers (Phillips and flathead)
* Brake fluid collector (essential to avoid spilling)
* New brake power booster
* New brake master cylinder (often replaced at the same time)
* C-clamps or a booster bench bleeding tool
* Brake fluid (DOT 3 or DOT 4, check your owner's manual)
* Shop rags or towels
* Safety glasses
* Gloves
Steps:
1. Safety First: Disconnect the negative battery terminal.
2. Drain Brake Fluid: Carefully open the brake fluid reservoir and use a brake fluid collector to drain as much fluid as possible. You'll likely need to top it off during the process.
3. Disconnect Components: Disconnect the brake lines from the master cylinder. Again, use the brake fluid collector to catch any spillage. Carefully label or photograph the lines to ensure proper reassembly.
4. Remove the Master Cylinder: This is usually bolted to the brake booster. You may need to remove the brake lines first. The bolts can be stubborn due to corrosion. Penetrating oil may be helpful.
5. Remove the Booster:
* Vacuum Hose: Disconnect the vacuum hose from the booster.
* Pushrod: Disconnect the pushrod connecting the booster to the master cylinder. This may require careful manipulation and potentially a special tool.
* Bolts: Remove the bolts securing the brake booster to the firewall. These can be difficult to access and may require extensions and swivel sockets.
6. Install the New Booster: This is essentially the reverse of the removal process. Ensure the pushrod is correctly aligned and adjusted.
7. Install the Master Cylinder: Reinstall the master cylinder, ensuring proper alignment and tightening the bolts to the correct torque specification.
8. Reconnect Brake Lines: Reconnect the brake lines carefully, ensuring they are secure and not leaking.
9. Bleed the Brakes: This is crucial to remove air from the brake lines. Use a brake bleeding procedure appropriate for your vehicle. This usually involves opening each brake bleeder valve individually while someone pumps the brake pedal.
10. Fill Brake Fluid Reservoir: Top off the brake fluid reservoir to the correct level.
11. Reconnect Vacuum Hose: Attach the vacuum hose to the booster.
12. Test the Brakes: After bleeding, carefully test the brakes in a safe, controlled environment. If the brakes feel spongy or unresponsive, repeat the bleeding process or seek professional assistance.
Important Considerations:
* Master Cylinder Replacement: Many mechanics recommend replacing the master cylinder along with the booster, as they often fail together or due to similar issues.
* Vacuum Leak Check: After installation, check for vacuum leaks around the booster.
* Torque Specifications: Refer to your repair manual for the correct torque specifications for all bolts and connections. Over-tightening can damage components.
* Professional Help: This is a complex repair with safety implications. If you are uncomfortable performing this work yourself, consider having a qualified mechanic do it for you.
This is a general guideline; specific details may vary depending on your vehicle's exact model and condition. Always consult a repair manual specific to your 1993 Chevy G20 before attempting this repair. Improperly completed brake work can lead to dangerous driving conditions.
