ISC, ISCe, QSC8.3, ISL, ISLe3, ISLe4 and QSL9 Engines – 008-129   Marine Gear Oil and Fuel Cooler Assembly

Shut off the sea water inlet valve on the vessel hull, if equipped.

Remove the marine gear oil cooler drain plug and drain the sea water from the gear oil cooler.

Disconnect the sea water inlet and outlet connections. Refer to Procedure 008-056.

Use clean water to back flush all the debris from the cooler.

Make sure the debris flushed from the cooler does not enter the water supply hoses.

Install the drain plug and sea water hose connections.

Open the sea water valve on the vessel hull, if equipped.

WARNING  Batteries can emit explosive gases. To reduce the possibility of personal injury, always ventilate the compartment before servicing the batteries. To reduce the possibility of arcing, remove the negative (-) battery cable first and attach the negative (-) battery cable last.

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 oil lines that oil is not spilled or drained into the bilge area. The oil must be drained into a suitable container and disposed of in accordance with local environmental regulations.

NOTE: This procedure applies to QSC8.3 marine engine only. Refer to Procedure 008-041 for QSL9 marine engines.

• Disconnect the batteries. Refer to Procedure 013-009.
• Shut off the fuel supply and drain valves. Refer to the OEM service manual.
• Disconnect the OEM fuel supply and OEM drain lines from the fuel cooler side of the assembly.
• Shut off the sea water inlet valve(s) on the vessel hull, if equipped. Refer to the OEM service manual.
• Disconnect the oil temperature and pressure sensor connectors from the OEM harness.
• Drain the sea water system by removing the two plugs at the bottom of the marine gear oil and fuel cooler assembly. Refer to Procedure 008-059.
• Disconnect the sea water inlet and outlet pipes. Refer to Procedure 008-056.

Disconnect the fuel supply hose from the lift pump to the fuel cooler at the fuel cooler.

Remove the mounting capscrews from the gear cooler to aftercooler.

Twist the cooler so the transmission oil supply and return lines can be removed.

Remove the transmission oil supply and return lines; mark their locations.

Disconnect the marine gear oil pressure/temperature sensor (if equipped).

Disconnect the braided fuel return hose from the rear of the cooler.

Place the cooler in a vise and remove the two oil line fittings from the gear cooler, if necessary. Mark the fitting locations prior to removal.

Plug one gear oil port and attach an air supply line to the other gear oil port with a quick disconnect fitting. Apply thread sealant to the threads to prevent leaks. Do not allow sealant to enter the gear oil cooler.

Repeat the leak test for the fuel side of the cooler assembly.

WARNING  Troubleshooting with high pressure air presents the risk of equipment damage, personal injury, or death. Troubleshooting must be performed by trained, experienced technicians.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Attach a high-pressure air supply source (air cylinder or other suitable source) with an air pressure regulator and an inline shutoff valve to the quick disconnect fitting.

Set the regulator test pressure to 1724 kPa [250 psi].

Submerge the gear oil cooler into a tank of water. Rotate the cooler to allow any trapped air to escape. Allow the cooler to remain submerged for one minute.

Inspect for air bubbles at the fitting braze joints.

Inspect for air bubbles at the opening at each end of the cooler.

If leaks are detected, replace the gear oil cooler.

Remove the cooler from the tank. Shut off the air supply and disconnect the air supply.

Remove the plug and test fitting.

Fabricate a test fixture to seal the sea water connections, or use connector hoses with a quick disconnect air connection to supply a regulated test pressure of 276 kPa [40 psi] to the sea water side of the gear oil cooler.

Submerge the cooler into a tank of water for one minute.

Inspect for air leaks at the braze joints of the end caps and any bubbles from the gear oil ports. If leaks are detected, replace the gear oil cooler.

Remove the cooler from the tank.

Shut off the air supply and disconnect the air supply.

Remove the test equipment.

WARNING  When using solvents, acids, or alkaline materials for cleaning, follow the manufacturer’s recommendations for use. Wear goggles and protective clothing to reduce the possibility of personal injury.

WARNING  Some solvents are flammable and toxic. Read the manufacturer’s instructions before using.

WARNING  Wear appropriate eye and face protection when using compressed air. Flying debris and dirt can cause personal injury.

Drain the water from the cooler.

Flush the oil and fuel sides of the cooler with clean solvent.

Use compressed air to dry the cooler.

Coat the threads with thread sealant and install the two line fittings into the gear cooler, if removed. Be sure they are oriented in the same direction as they were removed.

Install the oil temperature sensor on the right and the oil pressure sensor on the left. Tighten the sensors.

Connect the transmission oil supply and return lines to their original locations and tighten.

Connect the braided fuel return line to the fuel cooler and tighten.

Install the marine gear oil cooler to the aftercooler.

Tighten the capscrews.

Install the fuel supply hose from the lift pump through the cooler housing using two jam nuts.

• Connect the oil temperature and pressure sensor connectors from the OEM harness.
• Connect the sea water inlet and outlet pipe. Refer to the OEM service manual.
• Connect the OEM fuel supply and drain lines to the fuel cooler.
• Install the plugs in the bottom of the marine gear oil and fuel cooler assembly. Refer to Procedure 008-059.
• Open the sea water inlet valve(s). Refer to the OEM service manual.
• Open the fuel supply and drain valves. Refer to the OEM service manual.
• Connect the batteries. Refer to Procedure 013-009.

Operate the engine and check for leaks.