How to Pull the Sending Unit From a Tank in a 1997 Silverado

The 1997 Chevy Silverado base model was offered with the 4.3-liter six-cylinder engine and a five-speed manual transmission. With a maximum fuel economy of 20 mpg on the highway, the 1997 Silverado had to be equipped with a 25-gallon fuel tank to give a decent amount of drive time between fill-ups. The fuel-sending unit is located inside the fuel tank, which must be removed to gain access to the sending unit.

Instructions

Removal

1

Park the vehicle on a level surface and set the parking brake. Place the wheel chocks around the front wheels. Lift the vehicle hood and support it with the hood prop rod. Remove the lid for the fuse box and locate the fuel pump relay; it will be in the row of relays nearest the front of the vehicle, on the far passenger's side of the fuse box. Grasp the fuel pump relay and remove it from the fuse box. Start the engine and allow it to run until it stalls out to relieve the fuel pressure. Turn the ignition key to the Off position.

2

Open the fuel door and remove the fuel fill cap. Place the siphon pump hose into the fuel fill neck and feed it into the gas tank. Direct the opposite end of the siphon pump into the five-gallon gas can and drain the fuel tank. Fill each gas can to the Full line, and switch to the next gas can if necessary.

3

Lift the rear of the truck into the air with the floor jack and place the jack stands under the rear frame rails. Lower the floor jack until the rear of the truck rests securely on the jack stands. Shake the truck to make sure it is safe to work under. Remove the floor jack.

4

Remove the bolts for the fuel tank shield with the socket and ratchet and remove the shield from under the truck, if equipped. Loosen the clamp for the fuel fill neck with the screwdriver and disconnect the fuel filler neck from the tank.

5

Position the floor jack under the center of the gas tank and raise the jack arm until there is just enough room to fit the wood block between the fuel tank and the jack arm. Place the wood block onto the jack arm and raise the floor jack until the wood makes contact with the tank, but do not apply pressure to the tank.

6

Remove all four tank strap bolts with the socket and ratchet. Remove the fuel tank straps from under the truck. Instruct the helper to assist in balancing the tank, and lower the floor jack until there is enough room to disconnect the fuel pump connections.

7

Disconnect the fuel-sending and return lines with the quick disconnect tool. Disconnect the fuel tank vent hose from the fuel pump and disconnect the wiring harness from the fuel pump electrical connector. Lower the floor jack and slide the fuel tank from under the truck.

8

Install the spanner wrench onto the fuel tank lock nut. Rotate the spanner wrench and fuel pump lock ring counterclockwise until loose with the ratchet. Remove the spanner wrench and remove the fuel sending unit from the fuel tank.

Installation

9

Install the new sending unit O-ring onto the sending unit. Lower the fuel-sending unit it position. Secure the sending unit in the fuel tank by turning the lock ring clockwise with the spanner wrench and ratchet. Slide the fuel tank under the truck.

10

Lift the fuel tank onto the floor jack arm and wood block with the assistance of the helper. Instruct the helper to balance the fuel tank and raise the fuel tank high enough to install the sending unit connections. Slide the fuel-sending and return lines onto the fuel sending unit. The lines will make a distinctive click and will not pull away from the sending unit when properly connected.

11

Install the fuel tank vent hose onto the center outlet on the sending unit. Slide the fuel filler neck over its respective nipple on the fuel tank and tighten the clamp with the screwdriver. Raise the tank into position, against the base of the truck bed. Do not apply any unnecessary pressure to the bottom of the tank.

12

Raise the fuel straps into position and install the bolts hand tight. Tighten the fuel tank straps in the following sequence: Tighten all four bolts to 8 foot-pounds, then to 16 foot-pounds, then to 24 foot-pounds and finally to 33 foot-pounds with the torque wrench. Lower the floor jack and block of wood.

13

Install the fuel tank shield and tighten the bolts with the socket and ratchet, if equipped. Pour all the previously drained gas into the fuel tank through the fill neck. Install the fuel neck cap and tighten until it clicks three times.

14

Lift the rear of the truck off of the jack stands with the floor jack. Remove the jack stands from under the truck. Lower the rear of the truck to the ground and remove the floor jack.

15

Install the fuel pump relay into its respective socket in the fuse box and install the fuse box lid. Turn the ignition key to the On position for 2 seconds, and then turn it back to the Off position for a minimum of 10 seconds. Turn the ignition switch to the On position and inspect for any fuel leaks.