ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – 006-062   Fuel Cooler

This procedure applies to QSL9 marine sea water cooled (heat exchanger)
engines only.

WARNING  Fuel is flammable. Keep all cigarettes, flames, pilot lights, arcing equipment, and switches out of the work area and areas sharing ventilation to reduce the possibility of severe personal injury or death when working on the fuel system.

CAUTION  Use caution when disconnecting or removing fuel lines, replacing filters and priming the fuel system that fuel is not spilled or drained into the bilge area. Do not drop or throw filter elements into the bilge area. The fuel and fuel filters must be discarded in accordance with local environmental regulations.

CAUTION  Zinc plugs expand and can break off during removal. Inspect the zinc plug to make sure it is in one piece. If not, it must be replaced with a new zinc plug, and the broken pieces must be retrieved from the aftercooler to prevent damage to components downstream in the sea water system.

NOTE: This procedure applies to QSL9 engines only. Refer to Procedure 008-129 for QSC8.3 engines.

• Shut off the sea water supply valve(s). Refer to the OEM service manual.
• Drain the sea water system by removing a zinc plug from the aftercooler. Refer to Procedure 010-005.
• Shut off the fuel supply and return valves to the engine. Refer to the OEM service manual.
• Disconnect the fuel drain line from the combined fuel manifold to the fuel cooler at the fuel cooler connection. Refer to Procedure 006-013.
• Disconnect the fuel drain line from the fuel cooler to the fuel tanks.

Remove the hose clamps at the top and bottom of the fuel cooler.

Remove the fuel cooler.

Clean the hose sealing surfaces of the fuel cooler.

Inspect the core area of the fuel cooler for debris. Clean if required.

Inspect the core for damage to the inter core surfaces.

Pressure test the fuel side of the fuel cooler.

Install a plug in one end of the cooler.

Install fittings and apply shop air pressure.

Place the cooler in a tank of water and check for leaks.

Install the fuel cooler into the sea water hoses.

Tighten the hose clamps.

CAUTION  Failure to properly prime the fuel system on marine engines can result in damage to the fuel cooler. Be sure the drain valve(s) are open. Be sure a good flow of fuel is present through the fuel cooler by cycling the keyswitch at least five times before starting the engine. Refer to Procedure 005-016.

• Connect the fuel drain line from the fuel cooler to the fuel tanks. Refer to the OEM service manual.
• Connect the fuel drain line from the combined fuel manifold to the fuel cooler at the fuel cooler connection. Refer to Procedure 006-013.
• Open the supply and return valves to the engine. Refer to the OEM service manual.
• Open the sea water supply line(s). Refer to the OEM service manual.
• Prime the fuel system. Refer to Procedure 005-016.

Operate the engine and check for leaks.