MBE 900 OPERATOR'S GUIDE Coolant Flushing and Changing HOT COOLANT 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. Figure 50 Coolant Drain Plug NOTE: Make sure the coolant can flow unobstructed into the receptacle. [b] Open the coolant drain plug on the bottom of the radiator. Flush and change the coolant as follows: 4. Flush the radiator. 1. Open the cap on the surge tank slowly, to allow excess pressure to escape. Set the cap aside. NOTICE:
When flushing the radiator, do not apply more than 140 kPa (20 psi) air pressure. Excessive pressure can damage the radiator or heater core. 2. Open the water regulating valve for the heating system. 3. Drain the coolant from the engine. See Figure 50. Coolant system capacity is listed in Table 30. [a] Place a receptacle underneath the coolant drain plug. Choose one that is large enough to hold the expected quantity of coolant. [a] Attach a flushing gun nozzle to the radiator outlet. [b] Run water in until the radiator is full. All information subject to change without notice. (Rev. 04/08) 93 DDC-SVC-MAN-0055 04/08 Copyright © 2008 DETROIT DIESEL CORPORATION