GHG17 DD Medium Duty Operators Manual WARNING: EYE INJURY To avoid injury from flying debris when using compressed air, wear adequate eye protection (face shield or safety goggles) and do not exceed 276 kPa (40 psi) air pressure. NOTICE: Clean at moderate air pressures only to avoid damaging the radiator grille fins. 2. Remove the debris by blowing them through with compressed air or spraying them out with water. Work from the rear of the radiator (in the opposite direction of the normal cooling air flow). 3. Drain the coolant when the engine is cold. Refer to section "Cooling System Drain Procedure". For detailed procedures, see the vehicle/chassis maintenance manual.
For types of coolant, refer to the How to Select Coolant section for the listing of required intervals using the recommended coolants. 4. If the HVAC unit is connected to the cooling system, open the regulating valves all the way. 5. Fill the cooling system with a 5% solution of 50 grams per liter (1.6 ounces per quart) of water of a mildly alkaline cleaning agent. Refer to section "Coolant Selections and Maintenance". 6. Run the engine at moderate speed until the thermostat starts to open. The thermostat starts to open at 83°C (181°F) and is fully open at 95°C (203°F). Then run it for about five minutes longer. Shut down the engine and allow it to cool to approximately 50°C (112°F). 7.
Drain all the cleaning solution. 8. Flush the cleaning solution from the cooling system. Immediately after draining the cleaning solution, flush the system with clean water. 9. Once the clean water has drained, fill the system again with clean water. 10. Run the engine at moderate speed until the thermostat starts to open. The thermostat starts to open at 83°C (181°F) and is fully open at 95°C (203°F). Then run it for about five minutes longer. Shut down the engine and allow it to cool to approximately 50°C (112°F). 11. Drain the hot water. 12. Fill the cooling system with new coolant. For detailed procedures, see the vehicle/chassis maintenance manual.
For types of coolant, refer to section "How to Select Coolant" for the listing of required intervals using the recommended coolants. Coolant Selections and Maintenance This section covers selection of the required coolant for the engine. All information subject to change without notice. 95 DDC-SVC-MAN-0192 Copyright © 2017 DETROIT DIESEL CORPORATION