FLUSHING & CLEANING THE SYSTEM

Radiator and Engine Flush

1. Drain the cooling system. Remove the thermostat and reinstall the thermostat housing.
2. Disconnect the radiator overflow hose from the expansion tank and plug the end of the hose.
3. Disconnect the intake manifold outlet hose from the manifold nipple and plug both the nipple and the hose.
4. Disconnect the lower radiator hose from the radiator and position the hose to drain clear of the vehicle.
5. Connect a high pressure hose to the radiator lower hose outlet. Back flush the radiator and engine until water runs clear out of the lower radiator hose. Turn the water on and off several times to pulse the flow and help loosen sludge deposits.

   WARNING
   The flushing water flow must be limited so that pressure inside the radiator does not exceed 15 psi (103.4kpa).

6. When the system drains clear, unplug the radiator overflow hose. When water flows clear from the hose, reinstall the plug.
7. Before reconnecting the cooling system hoses, disconnect all of the hoses installed for the radiator and engine back flush procedure. The heater coolant loop must be backflushed separately to prevent loosened sediment from lodging in the heater core.

Heater Core Back Flush

1. Install and clamp a garden hose female end fitting in the heater return hose, disconnected from the bypass nipple.
2. Connect a garden hose to the hose fitting in the heater return hose and flush the heater core circuit until the drain water runs clear. Pulse the flow by turning the water on and off several times. Allow full flow for approximately 5 minutes.
3. Shut off the flushing water and remove all adapters and plugs installed for the flushing operation. Reconnect all cooling system connections and tighten the hose clamps to 22–31 inch lbs. (2.5–3.5 Nm).
4. Install the thermostat with a new housing gasket. Tighten the retaining nuts.
5. Fill the cooling system and check for leaks.