19279-ZW1-000 Honda SPRING, FLUSH VALVE (Honda Code 4898268).

When any servicing or repair of the engine cooling system is performed the procedure must be performed with the engine on level ground. Level ground will allow you to check accurately the coolant level. This procedure will also help in avoiding the risk of introducing an air lock into the coolant system.
Note: Inspect the water pump and the water temperature regulator after the cooling system has been drained. This inspection is a good opportunity to replace the water pump, the water temperature regulator, and the hoses, if necessary. Clean the cooling system and flush the cooling system before the recommended maintenance interval if the following conditions exist:
The engine overheats frequently.
Foaming is observed.
The oil has entered the cooling system and the coolant is contaminated.Note: When the cooling system is cleaned, only clean water is needed.Drain
Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure.
Stop the engine and allow the engine to cool. Loosen the cooling system filler cap slowly in order to relieve any pressure. Remove the cooling system filler cap.
Illustration 1 g03349949
Typical example
Open the drain cock or remove the drain plug (1) on the engine. Open the drain cock or remove the drain plug on the radiator. Allow the coolant to drain.
Dispose of used engine coolant properly or recycle. Various methods have been proposed to reclaim used coolant for reuse in engine cooling systems. The full distillation procedure is the only method acceptable by Caterpillar to reclaim the used coolant.
Properly dispose of the drained material. Obey local regulations for the disposal of the material.Flush
Flush the cooling system with clean water in order to remove any debris.
Close the drain cock or install the drain plug in the engine. Close the drain cock or install the drain plug on the radiator. Torque Specifications, SENR3130 for more information on the correct torques.
Do not fill the cooling system faster than 5 L (1.3 US gal) per minute to avoid air locks.Cooling system air locks may result in engine damage.
Fill the cooling system with a mixture of clean water and Caterpillar Fast Acting Cooling System Cleaner. Add 0.5 L (1 pt) of cleaner per 15 L (4 US gal) of the cooling system capacity. Install the cooling system filler cap.
Start and run the engine at low idle for a minimum of 30 minutes. The coolant temperature should be at least 82 °C (180 °F).
Stop the engine and allow the engine to cool. Loosen the cooling system filler cap slowly in order to relieve any pressure. Remove the cooling system filler cap. Remove the connection hose or remove the cooling system drain plugs. Allow the water to drain. Flush the cooling system with clean water. Install the connection hose. Clean the drain plugs. Install the drain plugs. Refer to Torque Specifications, SENR3130 for more information on the correct torques. Fill
Close the drain cock or install the drain plug on the engine. Close the drain cock or install the drain plug on the radiator.
Do not fill the cooling system faster than 5 L (1.3 US gal) per minute to avoid air locks.Cooling system air locks may result in engine damage.
Fill the cooling system with Commercial Heavy-Duty Coolant. Add Supplemental Coolant Additive to the coolant. For the correct amount, refer to the Operation and Maintenance Manual, "Refill Capacities" topic (Maintenance Section) for more information on cooling system specifications. Do not install the cooling system filler cap.
Start and run the engine at low idle. Increase the engine rpm to high idle. Operate the engine in order to open the engine thermostat. This operation will allow any air in the system to be purged. Decrease the engine speed to low idle. Stop the engine.
Check the coolant level. Maintain the coolant level within 13 mm (0.5 inch) below the bottom of the pipe for filling. Maintain the coolant level in the expansion tank (if equipped) at the correct level.
Clean the cooling system filler cap. Inspect the gasket that is on the cooling system filler cap. If the gasket that is on the cooling system filler cap is damaged, discard the old cooling system filler cap and install a new cooling system filler cap. If the gasket that is on the cooling system filler cap is not damaged, perform a pressure test. A 9S-8140 Pressurizing Pump is used to perform the pressure test. The correct pressure for the cooling system filler cap is stamped on the face of the cooling system filler cap. If the cooling system filler cap does not retain the correct pressure, install a new cooling system filler cap.
Start the engine. Inspect the cooling system for leaks and for correct operating temperature. Note: Caterpillar have various products in order to clean heavy deposits from the coolant system. Contact your Cat dealer for more information.