SCREW-TRUSS HEAD 9X2042 - Caterpillar

All EnginesSUPPLEMENT: 06/20/79ENGINE NEWS, JUNE 6, 1979, PAGE 2.In th article "New Type Products Available To Clean Cooling Systems", the ratio of cleaner to water for different percent solutions is not given correctly. The correct ratio for a 10% solution is 1 part cleaner to 9 parts water, and the correct ratio for a 20% solution is 2 parts cleaner to 8 parts water. Make corrections to these ratios in four places in the article as follows:
Under topic "A. Application", in paragraphs 1 and 2, and in the caution note.
Under topic "B. General Procedure", in Step 2.
--------------- END SUPPLEMENT ---------------A clean cooling system is very important to any engine for good efficiency and maximum service life. In most engine applications, deposits of rust and corrosion must be removed at intervals to prevent cooling problems. The amount of these deposits and the frequency of removal is in direct relation to the conditions of operation and the maintenance procedures used. A number of different products are normally used to remove deposits of rust and corrosion, but most of these products have a strong chemical action and must be used carefully to prevent injury or possible damage to the cooling system.
Now, a different type of product is available to clean cooling systems. Products of this type use a chelation chemical action, and are a development of the space industry. According to the manufacturers (sources), these products are much safer to use because they are:
... Neither acid nor alkaline... Biodegradable (safe for the environment)... Acceptable under the U.S. Department of Transportation rules for shipment by land, sea or air.The new products also have good characteristics for long storage and will not damage either metal parts, including aluminum, or other parts, including hoses and gaskets when correctly used, according to the manufacturer's information.
One manufacturer's recommendations for use of the new type product are:
A. Application
1. For average conditions, with light to medium amounts of rust and other material, use a 10% solution (1 part cleaner to 9 parts water).2. For heavy amounts of rust and other material, a stronger solution of 20% (2 parts cleaner to 8 parts water) can be used if needed.
If there are galvanized, zinc, or cast aluminum surfaces in the cooling system, do not use a solution stronger than 10% (1 part cleaner to 9 parts water). A weaker solution can be used, if necessary. Get recommendations from the manufacturer before use of the cleaner in these systems.
3. To clean the cooling system, the temperature of the solution in the system must be between a minimum of 160°F (71°C) and a maximum of 250°F (121°C) in a pressurized system. For best results, operate the system with the solution at a temperature between 180°F (82°C) and 200°F (93°C).4. The cleaner will remove some light oils from the system, but heavier oils must be removed with a solvent or other degreaser before the cleaner is put into the system. Where available, a good degreaser to use is a non-foaming (without bubbles) detergent,