Disconnect the fan clutch connector on the base harness from the fan clutch. NOTE: As the electric fan clutch mounting fastener is loosened, make sure to support the clutch. NOTE: The electric fan clutch mounting capscrew has an external TorxTM head. Remove the electric fan clutch mounting capscrew, washer and electric fan clutch. NOTE: Prior… Read More »
The Cummins Inc. developed electromagnetic fan clutch product is an integrated package with the clutch, bracket, shaft, bearings, pulley, and fan spacer designed as a unit. When cooling is needed, an electromagnet engages the fan . The fan is either fully engaged or fully disengaged. The electromagnetic fan clutch is driven by a poly-vee drive… Read More »
Check the color of fluid in the combustion gas leak tester. A yellow or green color will indicate a combustion leak. A blue color will indicate there is no leak. This information will help isolate the source of air in the cooling system, if any. NOTE: The test kit is not sensitive enough to detect… Read More »
Use a combustion gas tester, Part Number 3822985 or equivalent, to test for combustion gases in the cooling system. It is recommended that the cooling system contain a mixture of 50-percent antifreeze and 50-percent water during the combustion gas leak test. The use of water only can result in a color change in the test… Read More »
Allow the engine to cool and remove the radiator cap. Install a radiator pressure cap that has had the spring and the pressure relief valve removed to allow free flow from the overflow tube. Attach a rubber hose to the radiator overflow connection. Put the free end of the hose below the coolant level in… Read More »
Air in the coolant can result in loss of coolant from the overflow when the aerated coolant is hot. The heated air expands, increasing the pressure in the system, causing the cap to open. Similarly, coolant can be displaced through the overflow if the head gasket or a crack in the cylinder head leaks compression… Read More »
The operating pressure of the cooling system and the lubricating system can result in the mixing of the fluids if there is a leak between the systems: cylinder head gasket, lubricating oil cooler, etc. Transmission/power steering/hydraulic fluid can also leak into the coolant through radiator fluid coolers, if equipped. Refer to the OEM service manual.… Read More »
Connect an electronic service tool to the vehicle’s data link. Turn the keyswitch to the ON position. Monitor the coolant temperature with the electronic service tool. If equipped with an in-dash coolant temperature gauge, monitor coolant temperature with an electronic service tool and compare the cab temperature gauge reading. Replace the cab temperature gauge if… Read More »
Winter fronts can be used to reduce the engine warm-up time and help maintain engine heat in cold climate locations. The winter fronts must only cover part of the frontal area of the cooling system, leaving part of the frontal area open to air flow. Failure to leave part of the front area open to… Read More »
Shutters are designed to control airflow across the radiator. If the shutters fail to open when needed, the engine can run hot. Failure of the shutters to close can resu lt in too much airflow and the engine running cold. NOTE: Make sure the air temperature sensor is functioning correctly. Check the air-operated shutter controls.… Read More »