Procedure 3

Repair Procedure Number 3 for Fuel System Cleaning

Refer to Battery Disconnect Caution in Cautions and Notices in SI.

Remove the negative battery cables.

Take off the fuel cap to release pressure or vacuum in the tank.

Remove the fuel feed hoses from both sides of the fuel lift pump. Refer to Fuel Lift Pump Replacement in SI.

Remove the lift pump.

Remove the fuel manager/filter. Refer to Fuel Manager/Filter Replacement in SI.

Use low pressure air to blow out the fuel feed line, from the fuel filter manager end, toward the rear of the vehicle.

Remove the fuel filter from the fuel manager/filter housing. Refer to Fuel Filter Element Replacement in SI.

Wipe out the inside of the housing with a clean towel.

Remove the heater element from the housing. Refer to Fuel Heater Replacement in SI.

Remove the water in fuel sensing element from the housing. Refer to Water in Fuel Sensor Replacement in SI.

Clean the inside of the housing with GM Brake Parts Cleaner or equivalent.

Dry the housing completely.

Install the water in fuel sensor with a new seal. Refer to Water in Fuel Sensor Replacement in SI.

Tighten

Tighten the water in fuel sensor mounting screws to 2 N.m (18 lb in).

Install the heater element with a new 0-ring seal and tighten securely. Refer to Fuel Heater Replacement in SI.

Install a new fuel filter in the housing.

Install the fuel manager/filter housing to the engine. Refer to Fuel Manager/Filter Replacement in SI.

Tighten

Tighten the fuel manager/filter housing mounting bolts to 25 N.m (18 lb ft).





If the reference table indicates that the vehicle fuel injection pump has been updated with a ceramic roller-type pump, do not replace the pump. Go to step 19.














Identify the fuel injection pump roller type by checking the nameplate and referencing the table shown (see Figures 1, 2, and 3 above).

Replace the fuel injection pump. Refer to Fuel Injection Pump Replacement in SI. Call GM Technical Assistance to order a fuel injection pump.

Remove the fuel from the tank. Refer to Fuel Tank Draining Procedure in SI.

Remove the fuel sender. Refer to Fuel Sender Assembly Replacement in SI.

The fuel tank should be replaced if the tank is rusted internally.

Clean the fuel tank.

Remove the fuel strainer and replace if necessary. Refer to Fuel Sender Assembly Service in SI.

Install the fuel sender. Refer to Fuel Sender Assembly Replacement in SI.

Install the fuel tank. Refer to Fuel Tank Replacement in SI.

Install a new fuel lift pump. Refer to Fuel Lift Pump Replacement in SI.

Install both sides of the fuel feed line at the fuel lift pump. Refer to Fuel Lift Pump Replacement in SI.

Install clean diesel fuel into the tank until it is at least 1/4 full.

Install the fuel tank cap.

Install the negative battery cables.

Remove the ECM 1 fuse from the underhood relay center.

Use a suitable container to catch fuel.

Install a hose from the fuel injection pump inlet hose (hose to hose) at the fuel injection pump to a closed metal container with a capacity of at least 8 liters (2 gallons).

Crank the engine for 15 seconds with one minute cooling periods until clean fuel is pumped out.

Reinstall the inlet hose to the fuel injection pump.

Install the ECM 1 fuse in the underhood relay center.

Start the engine and check the entire fuel system for leaks while idling for 5 minutes.

Clear any DTCs.

Labor Operation Times for the replacement of the fuel filter element (J5420) and fuel system clean and flush (L1000) are maintenance repairs and have been removed from the Labor Time Guide. The replacement of the fuel filter element and fuel system clean and flush outlined in this bulletin may be customer pay.