Here's a general outline. This is NOT a substitute for a detailed repair manual specific to your 1977 Chevy Blazer. Consult a Haynes or Chilton manual for precise instructions, diagrams, and torque specifications. Differences exist between models (e.g., engine size, options).
1. Preparation:
* Safety First: Disconnect the negative battery cable. Allow the fuel system to depressurize. You might need to run the engine until it stalls, then wait a few minutes. This reduces the risk of fuel spraying.
* Gather Tools: You'll need socket wrenches (various sizes), possibly a fuel line disconnect tool, jack stands, a fuel pump wrench (special tool may be needed), safety glasses, gloves, rags, and possibly a new fuel filter (recommended while you're at it).
* Locate the Fuel Pump: It's usually mounted on the frame near the fuel tank. Consult your repair manual for the exact location on your specific Blazer model.
* Prepare for Fuel Spillage: Place absorbent material (rags, shop towels) around the area to catch any spilled fuel.
2. Accessing the Fuel Pump:
* Raise the Vehicle: Safely raise the rear of the Blazer using jack stands. Never work under a vehicle supported only by a jack.
* Remove Fuel Tank Access Panel (if applicable): Some Blazers have a dedicated access panel for the fuel pump; others may require dropping the fuel tank. Your repair manual will show you the correct method.
* Disconnect Fuel Lines: Carefully disconnect the fuel supply and return lines. You may need a fuel line disconnect tool to avoid damaging the lines. Have rags ready to absorb any spilled fuel. Mark the lines to ensure correct reinstallation.
* Disconnect Electrical Connector: Disconnect the fuel pump's electrical connector.
3. Removing the Fuel Pump:
* Remove Fuel Pump Bolts: Use the appropriate socket wrench to remove the bolts holding the fuel pump in place. A fuel pump wrench might be necessary to prevent damage to the pump.
* Lower the Fuel Pump: Carefully lower the fuel pump assembly.
4. Installing the New Fuel Pump:
* Install the New Fuel Pump: Install the new fuel pump in the reverse order of removal. Make sure it seats correctly.
* Reconnect Electrical Connector: Reconnect the fuel pump's electrical connector securely.
* Reconnect Fuel Lines: Carefully reconnect the fuel supply and return lines. Ensure tight connections to prevent leaks. Double-check against your markings.
* Reinstall Fuel Pump Bolts: Securely tighten the fuel pump bolts to the manufacturer's specifications (consult your repair manual).
* Lower the Fuel Tank (if applicable): Carefully lower the fuel tank back into place (if you removed it).
5. Final Steps:
* Lower the Vehicle: Carefully lower the Blazer from the jack stands.
* Reconnect Battery Cable: Reconnect the negative battery cable.
* Check for Leaks: Inspect all connections for leaks.
* Start the Engine: Start the engine and check for proper fuel pressure (use a fuel pressure gauge if you have one). Listen for unusual noises from the pump.
* Test Drive: Test drive the Blazer to ensure the fuel pump is functioning correctly.
Important Considerations:
* Fuel Pressure: Consult your repair manual for the correct fuel pressure specifications.
* Fuel Tank Safety: Be extremely careful when working near the fuel tank to avoid sparks or fire.
* Professional Help: If you're uncomfortable performing this repair, take your Blazer to a qualified mechanic. This is a potentially dangerous job if not done correctly.
This is a general guide, and variations exist depending on your specific Blazer's model and configuration. Always consult your repair manual for detailed, model-specific instructions. Improper repair can lead to serious problems, including vehicle damage and personal injury.
