D346 MARINE ENGINE Caterpillar


Cooling System

Usage:



Engine Jacket Water

Checking Coolant Level-Using Coolant Sight Level Gauge

If the engine is equipped with a sight level gauge on either the radiator, expansion tank, or heat exchanger system, the coolant level can be checked with the engine either running or stopped.

Add coolant whenever the coolant level is in the LOW level range. A warning device will be actuated when the level is lowered to the unsafe operating level.


SIGHT LEVEL GAUGE

Checking Coolant Level

With the engine stopped:

1. Slowly turn the filler cap to the first stop and release pressure.

------ WARNING! ------

Be careful. If the engine is warm-steam may spray outward under high pressure.

------WARNING!--------
2. Push the cap down; turn until the cap is released.
3. Maintain level to base of fill pipe. The coolant requires expansion space as it is heated.


PROPER COOLANT LEVEL

4. Make-up coolant should be one of the following, in the order of preference:
a. Permanent anti-freeze and fresh water solution.
b. Rust inhibitor and fresh water solution.
c. Drinkable water.
d. Any available untreated raw water-never salt water.

(a) Must be used if engine is to be shut down in below freezing weather without draining the coolant. (b) Can only be used when the coolant temperature is above freezing, or if the coolant will be immediately drained after shut down during below freezing temperatures.

(c) or (d) Should only be used as a "temporary fix". As soon as possible, return the system to either (a) or (b).

Checking Water Temperature Gauge Reading

The water temperature gauge should normally register in the NORMAL range when operating. However, with some systems, as long as the coolant does not boil the cooling system is functioning properly.

1. If the water temperature gauge continually registers near-or in the "HOT" range-without boiling, have the system checked to determine if the cooling system is functioning properly.
2. Frequently check the water temperature gauge while operating. Be sure to note any deviation from the normal reading.
3. Whenever the reading changes, investigate the cause and have necessary repairs made.

Draining Radiator Or Expansion Tank

Whenever it is necessary to drain the cooling system for repairs:

1. Shut the engine off.
2. Slowly turn the pressure cap to the first stop and release pressure.

------ WARNING! ------

Be careful. If the engine is warm-steam may spray outward under high pressure.

------WARNING!--------
3. Push the cap down and turn until the cap is released.
4. Open the drain valve for the radiator, or expansion tank.

Draining Complete Cooling System (D379, D398, D399 Engines)

1. Drain the radiator or expansion tank.
2. Remove the water pump drain plug.


COOLANT DRAIN

3. Remove the engine block right rear drain cover.


COOLANT DRAIN

4. Remove the drain plug from the elbow of the oil cooler.


COOLANT DRAIN

5. Remove the drain plugs from the front of the left and right water shields.


COOLANT DRAINS

6. Remove the front and rear drain covers from the left side of the engine block.
7. Remove the drain plug from the elbow on the left side of the flywheel housing.


COOLANT DRAIN


COOLANT DRAINS

8. Remove the aftercooler drain plugs.


COOLANT DRAIN

9. If equipped with a marine gear oil cooler, remove the oil cooler bonnet drain plug.


COOLANT DRAIN

10. Allow the coolant to drain.
11. Install all drain covers and plugs. Close the radiator or expansion tank drain valve.

Draining Complete Cooling System (D346, D348, D349 Engines)

1. Open the radiator or expansion tank drain.
2. Remove the left front elbow drain plug.


ELBOW DRAIN

3. Remove the oil cooler bonnet drain plug.


OIL COOLER WATER DRAIN

4. Remove the engine jacket water pump drain plug.


WATER PUMP DRAIN PLUG

5. Remove the auxiliary water pump drain plug if so equipped.


AUXILIARY WATER PUMP DRAIN

6. After draining, install all drain plugs.
7. If equipped with a marine gear oil cooler, remove the heat exchanger drain plug.


COOLANT DRAIN

8. Allow the coolant to drain.
9. Install all drain covers and plugs. Close the radiator or expansion tank drain valve.

Flushing Cooling System

To clean the cooling system, any good commercial radiator cleaning solution can be used. Follow the instructions included with the cleaner.

The cooling system can be cleaned using oxalic acid and sodium carbonate as follows:

1. Fill the cooling system with a solution consisting of 2 pounds of oxalic acid or sodium bisulfate (Na HSO4) with every 10 gallons of water. (Mix 25 grams with every 1 liter of water).
2. Start the engine and operate at operating temperatures for 1/2 to 1 hour.
3. Stop the engine and drain the cooling system.
4. Flush the system with clean water until the draining water is clear.
5. Install all drain plugs.
6. Fill with a solution consisting of 1/2 pound sodium carbonate crystals (Na2 CO3 10 H2O) with every 10 gallons of water. (Mix 6 grams with every 1 liter of water),
7. Start and run the engine for 10 minutes.
8. Stop the engine and drain the cooling system.
9. Flush the cooling system with clean water.
10. Install all drain plugs.

Filling Cooling System

1. Add antifreeze, if required.
2. Fill to correct level with water which is free as possible from scale forming minerals.
3. Fill the auxiliary water pump tank, if the raw water system was drained. Open the raw water valve.


AUXILIARY WATER PUMP FILL PLUG

4. Start and run engine for 10 minutes.
5. Remove the pressure cap and check the coolant level.
6. Add coolant, if needed, until coolant is to the bottom of the filler tube.
7. Install the radiator or expansion tank cap.

Fan Belts And Drive

1. Check belt wear.
2. Apply a 25 pound (10 kg) force, perpendicular to the belt, midway between the driver and driven pulley and measure the belt deflection.


MEASURING BELT DEFLECTION

3. If one belt in a set requires replacement, always install a new matched set of belts-never replace just the worn belt. If only the worn belt is replaced, the new belt will be carrying all of the load-as it will not be stretched as much as the older belts-and all of the belts will fail in rapid succession.

Adjusting The D346, D348 Or D379 Fan Belts

1. Loosen the four nuts holding the fan plate to the engine block.
2. Loosen locknut. Turn the adjusting screw until belt is adjusted properly.


ADJUSTING D379 FAN BELT

3. Tighten the four nuts and locknut.
4. Check the belt adjustment.

Adjusting The D349, D398 Or D399 Fan Belts

1. Loosen the idler pillow block mounting bolts.


LOOSENING MOUNTING BOLTS

2. Loosen the locknut on the pillow block positioning screw.
3. Turn the positioning screw until the belt is adjusted properly.


POSITIONING SCREW

4. Tighten the pillow block mounting bolts.
5. Tighten the locknut on the positioning screw.
6. Check the belt adjustment.

Lubricating D346, D348 Or D379 Fan Drive

Lubricate the fan drive bearing with grease; 1 or 2 strokes, 1 fitting.


FAN DRIVE BEARING

Lubricating D349, D398, D399 Fan Drive

1. Lubricate the idler pillow block bearings with grease; 1 or 2 strokes, 2 fittings.


IDLER PILLOW BLOCK BEARINGS

2. Lubricate the upper pillow block bearings with grease; 1 or 2 strokes, 2 fittings.


UPPER PILLOW BLOCK BEARINGS

3. D399 Engine only: Lubricate the lower pillow block bearing with grease; 1 or 2 strokes, 1 fitting.


LUBRICATING LOWER PILLOW BLOCK BEARING

Lubricating D399 Crankshaft Coupling

1. Rotate the crankshaft until the two lubricating plugs are 45° from horizontal.
2. Remove the lower plug.
3. Remove the upper plug and install a grease fitting.
4. Lubricate with grease until the grease appears at the lower hole.
5. Remove the fitting, wipe off the excess grease, and install both plugs.


REMOVING LUBRICATING PLUGS ON CRANKSHAFT COUPLING

Raw Water Zinc Rods

Salt water has a highly corrosive reaction with metal by a chemical action called "electrolysis". To prevent this chemical action taking place, with parts used in the raw water system, zinc plugs are placed in the raw water piping. Zinc is a relatively soft metal which reacts quite readily with the salt water. Thus, by the deterioration of the zinc, the raw water system parts are protected from corrosion.

The zinc rods must be inspected regularly and be replaced as they become deteriorated. The zinc rod plugs are painted red for easy identification.

Inspecting Zinc Rods

1. Move the governor control lever to the shut-off position.
2. Remove the two plugs with zinc rods from the aftercooler line.


ZINC PLUGS IN AFTERCOOLER LINES

3. Remove the two plugs with zinc rods from the raw water pump and line.


ZINC PLUGS IN RAW WATER PUMP AND LINE

4. Tap the zinc rods lightly with a small hammer.


INSPECTING ZINC ROD

5. Inspect the rods. If a rod has deteriorated, or flakes apart when tapped, install a new zinc rod.

Installing New Zinc Rod

1. Unscrew or drill the existing rod from the plug base.
2. Install a new rod in the plug base.


INSTALLING NEW ZINC ROD

3. Install the plug.
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