Here's a general outline of the steps involved. Specific procedures may vary slightly depending on the exact van model (e.g., G10, G20, G30) and engine. Consult a repair manual specific to your year and model for detailed diagrams and torque specifications. This is crucial for proper installation.
1. Safety First:
* Disconnect the negative battery cable. This is paramount to prevent sparks and potential explosions.
* Locate and relieve fuel pressure. This is usually done by carefully disconnecting the fuel pump relay (check your manual for its location). Start the engine and let it run until it stalls due to lack of fuel. This helps prevent fuel spraying upon pump removal. Some vehicles have a fuel pressure release valve that can be used instead.
* Work in a well-ventilated area. Gasoline fumes are dangerous.
* Wear safety glasses and gloves.
* Have a fire extinguisher readily available.
2. Access the Fuel Pump:
* Locate the fuel pump access panel. This is typically under the vehicle, usually near the rear axle. You might need to remove a panel in the bed of a pickup or lower the fuel tank in some cases. Consult your repair manual.
* Raise the vehicle securely using jack stands. Never work under a vehicle supported only by a jack.
3. Removing the Old Fuel Pump:
* Disconnect the fuel lines. This will involve fuel lines, electrical connectors, and possibly a fuel sending unit. Be prepared for some fuel spillage; use absorbent materials to clean up any leaks. Take pictures or make detailed notes of how the lines are connected.
* Remove the fuel pump retaining ring or bolts. The method varies depending on the model. It might be a threaded ring or a clamp.
* Carefully remove the fuel pump assembly. Be mindful of the fuel sender unit if it’s part of the assembly. It's often fragile.
4. Installing the New Fuel Pump:
* Compare the new pump to the old one. Ensure it's the correct replacement.
* Install the new fuel pump assembly, ensuring a secure fit.
* Reconnect the fuel lines and electrical connectors, matching them exactly to how they were previously connected. Double-check your work!
* Reinstall the retaining ring or bolts. Tighten to the manufacturer's specifications (refer to your repair manual).
* Lower the vehicle.
5. Testing and Final Steps:
* Reconnect the negative battery cable.
* Check for leaks. Carefully inspect all connections for leaks.
* Start the engine and let it run for several minutes to ensure the pump works correctly. Listen for the hum of the fuel pump (you should hear it briefly when you turn the key to the "on" position before cranking).
* Check for any fuel leaks or unusual noises.
Important Considerations:
* Fuel tank dropping: On some models, the fuel tank must be lowered to access the fuel pump. This is a significantly more involved task requiring additional tools and expertise.
* Fuel sending unit: The fuel level sending unit is often integrated with the fuel pump assembly. Handle it carefully during removal and installation.
* Repair manual: A factory service manual or a reputable repair guide specifically for your 1989 Chevy full-size van is essential. It will provide detailed diagrams, torque specifications, and troubleshooting information.
This is a complex procedure. If you're not comfortable performing this repair yourself, it's best to take your van to a qualified mechanic. Improperly installed fuel pumps can lead to serious safety hazards.
