The Chevrolet Astro van's fuel pump is a fully sealed unit and can't be rebuilt in any way. If the fuel pump is damaged, it needs to be completely replaced. The pump is not contained in any assembly within the fuel tank itself, so removing and replacing it is simpler than with other vehicles. Still, you need to take the same precautions prior to removal, like cutting off the fuel pressure.
Release all pressure from the fuel system. With the gas cap open, remove the three-terminal electric connector from the fuel tank. Start the engine and wait for it to stop. Disconnect the van battery's negative cable to isolate it from the van. Locate the fuel pump in the front of the engine along the passenger side.
Detach the fuel inlet hose, outlet line and vapor return hose from the pump (on some models, there isn't a vapor return hose connected). Use an extra wrench to hold the pump fitting as you disconnect the outlet line. A flare-nut wrench works best for the fuel line fitting.
Remove the fuel pump from the engine by removing its two mounting bolts. Watch for the pushrod falling out as you remove the pump and retrieve it if it does. Remove the mounting plate from the pump and discard the gasket.
Clean the mounting surface on the engine block, using lacquer thinner or acetone. Scrape off any traces of sealant and the old gasket.
Install the new fuel pump with the mounting plate and a new gasket. Apply a bit of heavy grease on the pushrod to hold it in place while installing. Give the mounting bolts a quarter turn at a time until they are securely tightened.
Reconnect the inlet hose, outlet line and vapor return hose, making sure the outlet line's fitting is tight and the hose clamps are secure.
Connect the negative battery cable, reconnect the electrical connector to the fuel tank and close the gas cap. Turn the ignition switch on for two seconds and then shut it back off for 10. Repeat this with the ignition switch five to 10 times to re-pressurize the fuel system.
Start the Astro's engine. Look for any leaks around the hoses and lines where you reconnected them.
