ASTM D2570 Test Method for Simulated Service Corrosion Testing of Engine Coolants
11. Procedure
11.1 Starting the Test - Fill the system with the coolant to be tested. Add 500 mL of test coolant to the coolant expansion tank. After the pump is started, check to ensure that the coolant is circulating. Run the unit for 5 min to ensure that the system is operating properly and to remove trapped air. If leaks are detected, make necessary mechanical corrections before proceeding.
11.2 Presoaking Test Specimens - With the system shut down, allow the specimens to remain in the coolant for 24 h under static conditions, no flow and no heat.
11.3 Pressurizing the Unit - Apply heat and bring the system up to the test temperature. Pressurize the system to 15 psi (103 kPa) or slightly below. Close shut-off valve in air line. Maintain this pressure throughout the test when the unit is operating. Release the air pressure when the system is shut down and repressurize when starting up again.
11.4 Conducting the Test - Operate the simulated service unit continuously except for two 8-h shutdowns per week. The interval between shutdowns should be about 3 days; shutdowns starting at the same time on Mondays and Thursdays, for example, would be satisfactory. During the shutdowns, do not remove the radiator cap. If coolant level in expansion tank changes significantly, check for leaks. Follow this schedule, at 152 net hours of operation per week, until 1064 h of operation have been completed.
11.5 Coolant Sampling - Take samples of the coolant at the start and conclusion of the test. Inspect the coolant samples for visual appearance: color, turbidity, amount, and characteristics of sediment, etc. Determine the pH and reserve alkalinity of the samples in accordance with Test Methods D1287 and D1121, respectively. Determination of the concentration of antifreeze is optional but should be done when sudden changes in pH or reserve alkalinity are found.
11.6 Terminating the Test - Terminate the test after 1064 h of operation. Earlier termination may be necessary if excessive leakage or malfunction of the components should occur.
11.7 Specimen Cleaning - Immediately disassemble the bundles of metal test specimens and clean in accordance with the procedures in Test Method D1384.
11.8 Component Inspection - As soon as possible after termination of the test, disassemble and inspect the interior surfaces of all the components of the test system. If leakage from a component has occurred during the test, examine the component to determine the cause of the leakage.
