HOW-TO SECTION How to Drain and Flush the Cooling System 3. Start the engine and operate it for fifteen minutes to circulate the solution thoroughly. Drain and flush the cooling system as follows: 4. Stop the engine and allow it to cool. 5. With the engine cool, drain the cooling system completely. HOT COOLANT 6. Refill the cooling system with clean, soft water and operate it for fifteen minutes. To avoid scalding from the expulsion of hot coolant, never remove the cooling system pressure cap while the engine is at operating temperature. Wear adequate protective clothing (face shield, rubber gloves, apron, and boots). Remove the cap slowly to relieve pressure. 7.
Stop the engine and allow it to cool. 8. With the engine cool, drain the cleaner residue from the cooling system. 9. Refill the system with the required coolant. Refer to section How to Select Coolant. 1. With the engine cool, drain the previous solution from the engine and radiator. Dispose of the coolant in an environmentally friendly manner, according to state and/or federal (EPA) recommendations. 10. Entrapped air must be purged after filling the cooling system. To do this, allow the engine to warm up without the pressure cap installed. With the transmission in neutral, increase engine speed above 1000 RPM and add coolant as required.
Install the pressure cap after the coolant level has stabilized at the bottom of the radiator filler neck. 2. Refill the cooling system with clean, soft water and a good cooling system cleaning compound, such as those listed in Table 37 in the Specifications section. If the engine is warm, fill slowly to prevent the rapid cooling and distortion of the metal castings. 106 All information subject to change without notice. DDC-SVC-MAN-0039 Copyright © 2009 DETROIT DIESEL CORPORATION