Signs that the fuel pump is going bad on the Chevrolet 6.5-liter diesel engine can include misfiring, sputtering or the feeling that the engine is going to quit. When you begin to see these symptoms, your best bet is to replace the pump as soon as possible, before the truck leaves you stranded on the road. These instructions are specific to the multi-port fuel injection system; however, for those trucks with a central sequential fuel injection system, the process is the same. The project will take about three hours to complete for the average person.
Instructions
- 1
Open the engine compartment on the Chevy truck and prop the hood with the prop rod. Loosen the nut on the negative battery terminal and disconnect it from the battery. This will prevent accidental shorting of the electrical components. Loosen the gas cap on the truck. Connect the fuel pressure gauge to the fuel line at the fuel rail.
2Wrap a shop towel around the fitting so that it doesn't leak diesel fuel onto the engine. Place the bleed hose into a drain pan and open the valve to relieve the pressure on the fuel system. Raise the truck at the rear, using an automobile jack. Place a jack stand under the Chevy, near the jacking point. Raise it to the frame of the truck.
3Drain the fuel from the tank by disconnecting the fuel line at the tank, using a wrench. Remove the clamp from the fuel filler neck, using a screwdriver. Remove the heat shield from the fuel tank, using a wrench. Loosen the bolts on the fuel tank retaining straps, using a socket and ratchet. Lower the tank carefully to the ground.
4Unplug the wiring harness from the fuel tank. Disconnect the fuel hoses from the tank, using a pair of pliers to release the hose clamps. Remove the fuel tank from under the truck. Remove the fuel-sending assembly from the gas tank, using the fuel pump wrench to turn it counter-clockwise. Remove the sending unit from the fuel tank.
5Pull the fuel pump up and out from the bottom support. Take care not to damage the rubber seal or the fuel strainer basket when you remove the pump. Check the fuel pump hoses and insulation for signs of deterioration and damage. Replace them, if necessary. Make sure the fuel strainer is clean, with nothing blocking it.
6Install the new fuel pump into the fuel tank. Install the fuel pump sending unit and a new O-ring into the tank. Install the fuel-sending unit retaining ring and tighten it with the fuel pump wrench by turning it clockwise to lock it into place. Connect the wiring harness and fuel hoses to the fuel tank. Raise the tank into place under the Chevy.
7Secure the fuel tank by installing the retaining straps. Tighten the bolts with a socket and ratchet. Connect the clamp to the fuel filler neck and tighten it with a screwdriver. Fill the fuel tank with diesel fuel and secure the cap on the fuel tank filler neck. Remove the jack stand from under the truck and lower the vehicle to the ground.
8Connect the negative battery cable and tighten the terminal nut, using a wrench. Start the truck to test the new fuel pump.
