3406 MARINE ENGINE Caterpillar

Checking Oil Level

The dipstick is stamped on both sides of the blade. One side is marked and to be read when checking the oil level with the ENGINE STOPPED. The other side is marked and to be read with the ENGINE IDLING - HOT OIL. Each side is stamped to remind you not to OVERFILL the crankcase with oil.

Checking Oil Pressure

Immediately after starting, and frequently during operation, observe the oil pressure gauge reading. The indicator should register in the NORMAL range.

If the indicator fluctuates or registers below NORMAL range:

1. Move the governor control to low idle postion.

2. Check the oil level. Be sure to read the ENGINE IDLING side of the dipstick.

3. Add oil until the oil level is at the FULL mark on the ENGINE IDLING side of the dipstick. Do not overfill.

4. Check for oil leaks.

5. If necessary, stop the engine and have repairs made.

Draining Engine Oil

With engine stopped and oil warm:

1. Remove the crankcase oil drain plug.

2. Allow the oil to drain.

3. Clean and install the drain plug.

OR, if a sump pump is used:

1. Connect a suitable drain line and container to the pump outlet (1).

2. With engine stopped and oil warm, open the sump pump valve to the engine crankcase drain line: The two marks on the valve must be turned so that one mark points to the pump, and the second mark points to the engine drain line.

3. Close the valve to the marine gear housing drain: The two marks on this valve must be at right angles to the mark pointing towards the marine gear drain line.

4. Operate the sump pump handle until the crankcase is empty.

5. Close the valve to the engine crankcase drain line.

Cleaning the Breather

1. Release the hose clamp and disconnect the fumes disposal tube.

2. Remove the breather assembly.

3. Wash the breather in solvent.

4. Allow to drain dry and then wipe.

5. Inspect the gasket. Install a new gasket if necessary.

6. Install the breather.

7. Connect the fumes disposal tube.

Changing Oil Filter

1. Unscrew and remove the filter.

2. Be sure the old filter gasket did not remain attached inside the filter base: Leaking will occur between the new filter gasket and this old gasket.

3. Wipe the filter base.

4. Apply a thin coat of clean oil to the gasket of the new filter.

5. Install the new filter: Hand tighten the filter 3/4turn after the filter gasket contacts the base. Use the rotation index numbers, which are painted on the filter can, as a guide for proper tightening.

Filling the Crankcase

1. Fill the crankcase to the safe starting range on the ENGINE STOPPED side of the dipstick. See the Lubrication and Maintenance Chart for refill capacity and proper oil viscosity.

2. Start the engine and check for oil leaks.

3. After the engine is warm, check the oil level with the engine idling.

4. Add oil if necessary to maintain the oil level at the FULL mark on the ENGINE IDLING side of the dipstick.