Remove, Inspect and Clean Engine Heat Exchanger Core

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Heat Exchanger End Cap

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Remove Heat Exchanger Core

A - Clamp

B - End Cap

C - End Cap

D - Heat Exchanger Core

IMPORTANT: Initially remove and inspect the engine heat exchanger core at 250 hour or three month service interval on a new engine. Then, remove and clean at every 500 hour or 12 month interval thereafter.

1. Close sea cocks and drain the sea water system.

2. Open drain cock on cylinder block and drain approximately two gallons of engine coolant into a clean container. Close drain cock.

On 4045D Engines Only:

3. Loosen hose clamp (A) and remove hose from rear end cap (B).

4. Remove two end cap mounting cap screws and remove end cap (C) with heat exchanger core (D) from rear of engine.

On 4045T, 6068T and 6068SFM50 Engines Only:

3.

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Heat Exchanger End Cap

4. Remove two end cap mounting cap screws (B) and remove end cap with heat exchanger core from front of engine.

On 6068SFM75 / AFM75 Engines Only:

3.

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Remove Rear End Cap

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Remove Front End Cap

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Remove Heat Exchanger Core

A - Rear End Cap

B - Front End Cap

C - Heat Exchanger Core

4. Remove end cap mounting cap screws and remove front end cap (B). Remove heat exchanger core (C) from rear of heat exchanger.

On All Engines:

NOTE: The heat exchanger core may be removed from housing when either end cap is removed. It is strongly recommended that both end caps be removed for cleaning when cleaning the heat exchanger core.

5.

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Clean Heat Exchanger

6. Thoroughly clean all buildup from both end caps and inspect zinc plug in each. Replace plugs as needed. (See INSPECT AND REPLACE ZINC PLUGS in 250 Hour Section.)

7. Use a 4.76 mm (3/16 in.) diameter brass rod to clean out any buildup in each heat exchanger tube. Run the rod the entire length of each tube to push debris out.

8. Flush the heat exchanger tubes with clean water, making sure all tubes are cleared of debris. Clean (with brass rod) and flush heat exchanger again if necessary to remove any remaining debris from tubes.

If you suspect that your heat exchanger core is defective, have your authorized servicing dealer or engine distributor pressure test for leaks. Replace heat exchanger core as required.

9. Remove and thoroughly clean water manifold/heat exchanger housing if needed.