N14 Base Engine Troubleshooting and Repair Manual – 008-018   Cooling System

Position the vehicle on level ground.

WARNING  Wait until the coolant temperature is below 50°C [120°F] before removing the system pressure cap. Failure to do so can cause personal injury from heated coolant spray.

Remove the radiator cap after the engine is cool.

WARNING  Coolant is toxic. Keep away from children and pets. If not reused, dispose of in accordance with local environmental regulations.

Drain the cooling system as follows:

• Open the radiator draincocks.
• Remove the lower radiator hose(s).

If the coolant is to be used again, the container must be free of oil and dirt. Before pouring coolant back into the engine, it must be tested for SCA concentration. Refer to Procedure 018-004.

• Open the engine draincock.
• Open the oil cooler draincock (or plug).

Close the radiator draincocks.

Install the lower radiator hose(s).

Tighten the hose clamps.

Close the engine draincock.

Close the oil cooler draincock (or plug).

Cummins Inc. recommends using either a 50/50 mixture of good quality water and fully formulated antifreeze, or fully formulated coolant when filling the cooling system. The fully formulated antifreeze or coolant must meet TMC RP 329 or TMC RP 330 specifications.

Good quality water is important for cooling system performance. Excessive levels of calcium and magnesium contribute to scaling problems, and excessive levels of chlorides and sulfates cause cooling system corrosion.

Cummins Inc. recommends using Fleetguard® Compleat. It is available in both glycol forms (ethelyne and propylene) and complies with TMC standards.

Fill the cooling system with heavy duty coolant and install the correct service filter. Refer to Procedure 018-004.

NOTE: Some radiators have two fill locations, both of which must be filled when the cooling system is drained.

Fill the cooling system with coolant to the bottom of the fill neck in the radiator fill (or expansion) tank.

Install the radiator or expansion tank fill cap.

Operate the engine until it reaches a temperature of 82°C [180°F], and check for leaks.

WARNING  Do not remove the pressure cap from a hot engine. Wait until the coolant temperature is below 50°C [120°F] before removing the pressure cap. Heated coolant spray or steam can cause personal injury.

Shut off the engine, and allow it to cool.

CAUTION  Do not add cold coolant to a hot engine. This can cause engine casting damage. Allow the engine to cool to below 50°C [120°F] before adding coolant.

Remove the radiator or fill cap, and check the coolant level per the OEM service manual recommendations. Add coolant if necessary. Do not over fill.

WARNING  Wait until the temperature is below 50°C [120°F] before removing the coolant system pressure cap. Failure to do so can cause personal injury from heated coolant spray.

To confirm and locate external cold coolant leaks, it is not necessary to warm the engine.

Check the coolant level per the OEM service manual recommendations and fill, if necessary.

Add heavy duty coolant. Refer to 018-004 for description.

CAUTION  Do not apply more than 140 kPa [20 psi] air pressure to the cooling system. The water pump seal can be damaged.

If the radiator is equipped with a pressure relief valve, install a plug into the overflow tube (1).

Install the pressure tester onto the radiator fill neck or surge tank (if equipped), and apply 140 kPa [20 psi] maximum air pressure.

Inspect for coolant leaks and repair if necessary.

Remove the pressure test equipment and the plug from the pressure relief valve overflow tube (if equipped).

Install the coolant system pressure cap.