Diesel Engine
At the intervals specified in the maintenance schedule, or whenever the coolant becomes dirty, flush and refill the cooling system as follows, based on the type of engine installed in the vehicle.
Warning: Never remove the surge tank cap while the engine is operating or while the engine and radiator are still hot. Scalding fluid and steam can blow out under pressure if the cap is taken off too soon. Failure to follow these precautions could result in serious personal injury from heated coolant spray.
- When the engine is cool, remove the surge tank cap.Turn the cap slowly counterclockwise until it reaches a "stop." Do not press down while turning the cap. Wait until any remaining pressure (indicated by a hissing sound) is relieved, then press down on the cap and continue turning it counterclockwise.
- When the cap is removed, run the engine until the upper radiator hose is hot. This shows that the thermostat is open and that the coolant is flowing through the system.
- Shut down the engine. Remove the lower radiator hose and drain the coolant. Draining may be speeded up by removing the plug from the bottom of the water inlet.
- Connect the lower radiator hose and install the plug in the bottom of the water inlet. Add water until the system is filled and run the engine until the upper radiator hose is hot again. The system must be filled slowly to prevent air locks. Wait 2 to 3 minutes to allow air to be vented, then add water to bring the level to the top.
- Repeat the last two steps several times until the drained liquid is nearly colorless.
- Drain the system, then close the radiator and block the drain valves.
- Disconnect all hoses from the coolant surge tank. Remove the surge tank and pour out any fluid. Scrub and clean the inside of the surge tank with soap and water. Flush it thoroughly with clean water, then drain it. Reinstall the surge tank and hoses.
- Fill the cooling system.
- Slowly add a 50/50 mixture of antifreeze and water to the
surge tank, no more than 3.0 gallons per minute (gpm). Fill to the
top of the surge tank. For approved coolants, refer to the coolant
label on the vehicle or the engine manufacturer's service literature.
Coolant used must be compatible with the engine manufacturer’s
coolant specifications. For Cummins engine service literature, refer
to the Cummins Online website, see https://www.cummins.com/support/manuals or scan
the QR code. See Fig.. For Detroit™ engine service
literature, refer to the Detroit Diesel link on the DTNA
TechLit website, see https://www.dtnatechlit.com/portal-public or scan
the QR code. See Fig..
Fig. 1, Cummins QR Code
Fig. 2, TechLit QR Code
- With the radiator cap removed, start the engine and run it at low idle for 1 minute; then at high idle for 1 minute. Return to low idle for 1 minute.
- Turn the engine off. Fill the surge tank to the COLD MAX line. Install the radiator cap.
- Slowly add a 50/50 mixture of antifreeze and water to the
surge tank, no more than 3.0 gallons per minute (gpm). Fill to the
top of the surge tank. For approved coolants, refer to the coolant
label on the vehicle or the engine manufacturer's service literature.
Coolant used must be compatible with the engine manufacturer’s
coolant specifications. For Cummins engine service literature, refer
to the Cummins Online website, see https://www.cummins.com/support/manuals or scan
the QR code. See Fig.. For Detroit™ engine service
literature, refer to the Detroit Diesel link on the DTNA
TechLit website, see https://www.dtnatechlit.com/portal-public or scan
the QR code. See Fig..
Warning: Drain the coolant only when the coolant and engine are cool. Draining it when these are hot could cause severe personal injury due to scalding.
Notice: During filling, air must be vented from the engine coolant passages. Any air trapped in the system can cause severe engine damage.
Important: The coolant capacity varies depending on the engine and accessory installation. After servicing the cooling system, always verify that the coolant level is between the MIN and MAX lines on the surge tank.