Flush Coolant System (Tier 2/Stage II and Tier 3/Stage III)

CAUTION:

TS281-UN-15APR13

High-Pressure Fluids

Shut OFF engine and remove key. Only remove filler cap when cool enough to touch with bare hands. Slowly loosen cap to first stop to relieve pressure before removing completely.

NOTE: When Cool-Gard™ II or Cool-Gard™ II PG is used, the drain interval is 3 years or 3000 hours of operation.

If a coolant other than Cool-Gard™ II or Cool-Gard™ II PG is used, reduce the drain interval to 2 years or 2000 hours of operation.

Drain old coolant, flush the entire cooling system, replace thermostats, and fill with recommended clean coolant.

1. 
   CQ280164-UN-13FEB08

   
   NW271170-UN-15MAY06

   Water Pump Drain Valve

   
   NW271180-UN-23MAY06

   Engine Block Drain Valve

   A - Surge Tank Cap

   B - Water Pump Drain Valve

   C - Engine Block Drain Valve

   Slowly open the engine cooling system surge tank cap (A) to its first stop to relieve pressure and allow coolant to drain faster.

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2. Open water pump drain valve (B) and engine block drain valve (C) on left-hand side of engine. Drain coolant from engine block.

3. IMPORTANT: Thermostats must be removed to allow entire cooling system to be flushed.

   Remove thermostats now, if not previously done. Install cover (without thermostats) and tighten cap screws to 20 N·m (15 lb·ft).

4. Close all drain valves after coolant has drained. Fill the cooling system with clean water. Run the engine for about ten minutes to stir up possible rust or sediment.

5. Stop engine and immediately drain the water from system before rust and sediment settle.

6. After draining water, close drain valves and fill the cooling system with clean water and Heavy Duty Cooling System Cleaner, such as Fleetguard® Restore® and Restore PLUS™. Comply with the manufacturer's instructions.

7. After cleaning the cooling system, drain cleaner and fill with water to flush the system. Run the engine about ten minutes, then drain out flushing water.

8. Close drain valves on engine block and water pump. Install thermostats using a new gasket.

9. IMPORTANT: Air must be expelled from cooling system when system is refilled. Loosen temperature sending unit fitting in cylinder head or plug in thermostat housing to allow air to escape when filling system. Retighten fitting or plug when all the air has been expelled.

   Add coolant to coolant tank until it reaches bottom of filler neck. See Fill Cooling System in Maintenance—As Required section.

10. Run engine until it reaches operating temperature. This mixes the solution uniformly and circulates it through the entire system. Normal coolant temperature varies from 76—94°C (170—202°F).

11. After running the engine, check coolant level and entire cooling system for leaks.