The fuel pump on the 2000 Chevy Blazer bolts inside the fuel tank. The fuel tank on the Blazer bolts under vehicle between the rear axle and the back bumper. To access the fuel pump, you must lower the tank from the Blazer. Unfortunately, there is no way to access the pump without removing the tank. If the tank is more than a quarter full, siphon the fuel from the tank before starting the replacement process.
Remove the back bolts that secure the tank straps to the underside of the Blazer with a socket and ratchet. Allow the back of the tank (side closest to the bumper) to slide down. This will expose the fuel pump bulkhead, vent hoses and wiring harness on the top of the tank.
Remove the clamps that secure the vent hoses to the bulkhead with a pair of pliers. Pull the hoses off the bulkhead.
Disconnect the wiring harness on the bulkhead.
Remove the bolts that hold the front straps into place with your socket and ratchet and lower the tank to the ground.
Place an aluminum or brass rod against the raised flange on the bulkhead retaining ring and strike the rod with a mallet to turn it counterclockwise. Do not use a ferrous metal rod like iron, as it could cause sparking.
Pull the bulkhead off the gas tank. The pump connects to the underside of the bulkhead.
Disconnect the wiring harness from the underside of the bulkhead and then unsnap the fuel pump from the bulkhead.
Plug the new gas pump into the Blazer's gas tank bulkhead and then plug in the wiring harness to the underside of the bulkhead.
Place the bulkhead onto the top of the gas tank and secure it with the bulkhead retaining ring.
Lift the back half of the tank up and secure the wiring harness to the top of the bulkhead and then secure the vent hoses to the bulkhead using the clamps and pliers.
Push the tank against the bottom of the Blazer and secure it using the tank straps, bolts and socket.
