CYLINDER BLOCK GP 3533970 - Caterpillar

3208, 3300, And 3400 Marine EnginesCOOLANT MIXTURE
The jacket water cooling system of marine engines with a factory installed heat exchanger/expansion tank or with a remote mounted heat exchanger with or without an auxiliary expansion tank must use the recommended coolant mixture and follow the recommended maintenance schedule.
Caterpillar recommends the coolant mixture used in the engine cooling system contain:
* A minimum of 30 percent Caterpillar Antifreeze and 70 percent distilled or deionized water.* A maximum of 60 percent Caterpillar Antifreeze and 40 percent distilled or deionized water.Tap water, even artificially softened with salt, is not recommended.
The engine cooling system can contain a mixture of Supplemental Coolant Additive (SCA) and distilled or deionized water in conditions where freeze protection is not required.
Both the antifreeze/water mix, and the SCA/water mix should be maintained according to the Cooling System Specifications and Maintenance Schedule in the Operation And Maintenance Manual for the engine. The cooling system MUST contain SCA (conditioner or inhibitor) to control corrosion, cavitation, and deposits. The SCA also helps prevent rust, scale, and pitting of engine parts contacted by the coolant. The engine coolant should be tested regularly for SCA concentration. Coolant with antifreeze should have an SCA concentration of 3 to 6 percent. Coolant without antifreeze should have an SCA concentration or 6 to 8 percent.
Caterpillar Antifreeze includes Supplemental Coolant Additive (SCA).COOLING SYSTEM PRESSURIZATION
Engines with factory installed expansion tanks MUST be operated with the factory installed pressure cap.
Increased engine cooling system pressure reduces the possibility of cylinder liner pitting. An auxiliary expansion tank is not generally required when a factory installed heat exchanger/expansion tank is used. But, an auxiliary expansion tank is needed with large volume cooling systems. Refer to the Marine Application And Installation Guide. When using an auxiliary or remote mounted expansion tank, see the following chart for the recommended pressure cap and expansion tank height combinations.
Past production of 3300, 3176, and 3400 Marine Engines utilized 48 kPa (7 psi) pressure caps. Engines with 48 kPa (7 psi) pressure caps can be updated to 96 kPa (14 psi) pressure caps by using a 036-1865 Cap on 3176 and 3412 Marine Engines or a 031-1119 Cap on 3300, 3406, and 3408 Marine Engines. This will provide additional cooling system protection.