Cummins ISX11.9 CM2250 – Service Manual 008-060   Supplemental Coolant Additive (SCA)

NOTE: Cummins Inc. recommends DCA4 as the Supplemental Coolant Additive. DCA4 is compatible with all permanent-type antifreeze except Methoxy Propanol. If Methoxy Propanol antifreeze is used, reduce the amount of DCA4 by one-third. This will prevent inhibitor loss due to precipitation, caused by chemical incompatibility.

Check the DCA4 concentration level whenever coolant is added to the cooling system between filter changes.

Use Fleetguard® coolant test kit, CC2626, to check the concentration level. Instructions are included with the test kit.

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.

Operate the engine and check for coolant leaks.

After the air has been purged from the cooling system, check the coolant level again.

A supplemental coolant additive (DCA4) is used to prevent the buildup of corrosion and scale deposits in the cooling system.

CAUTION  Inadequate concentration of coolant additives can result in liner pitting and system corrosion. Excessive concentration can result in water pump seal leakage.

The recommended concentration level of supplemental coolant additives is 1.5 units per 3.8 liters [1 gal] of coolant. The additive level must not drop below 1.2 units or exceed 3 units per 3.8 liters [1 gal] of coolant.

When changing the coolant, the initial DCA4 concentration must be between 1.5 units and 3 units per 3.8 liters [1 gal] of coolant (initial charge).

NOTE: The cooling system must be clean before adding DCA4.

Use the following procedure for cleaning instructions. Refer to Procedure 008-018 in Section 8.

If coolant is added between drain intervals, additional DCA4 will be required unless the added coolant is precharged with additives as described in this section.

If coolant is added between drain intervals, additional SCA or equivalent will be required.

Cummins Inc. recommends using either a 50/50 mixture of high 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. Refer to Cummins® Coolant Requirements and Maintenance, Bulletin 3666132.