Cooling system - draining, flushing and refilling

Cooling and heating systems / Cooling system - draining, flushing and refilling

1 Set the heater temperature lever to maximum.

2 Unscrew the cap from the expansion tank.

3 Disconnect the radiator bottom hose and unscrew the cylinder block drain plug (1116 cc and 1301 cc engines) and allow the coolant to drain. Refer to photo 29.21B, page 64.

4 If the system is in good condition with no sign of rust or dirt in the drained coolant, then it may be refilled immediately. If the system has been neglected and the antifreeze has not been regularly renewed and there is evidence of rust and sediment in the drained liquid then flush the system through with a cold water hose.

5 If the radiator should appear to be clogged, it may be necessary to remove it (Section 7) invert it and reverse flush it using a cold water hose. If, after a reasonable period the water still does not run clear, the radiator should be flushed with a good proprietary cleaning system. Extensive damage should be repaired by a specialist or the unit exchanged for a new or reconditioned radiator.

6 Reconnect the bottom hose and screw in the drain plug.

7 Remove the plug (B) (Fig. 2.2) from the bleed hole in the heater hose.

8 Remove the plug (D) (Fig. 2.3) from the bleed hole in the expansion tank.

9 Pour antifreeze mixture slowly into the filler neck of the expansion tank until it is seen to come out of the expansion tank plug hole.

Screw in the plug.

10 Add further coolant until it is seen to dribble out of the hole in the heater hose.

Screw in the plug.

11 Top up the expansion tank to the specified level and screw on the tank cap.

12 Start the engine and run it until the cooling fan cuts in. Switch off, allow to cool and top up if necessary to the specified mark on the expansion tank.

Fig. 2.2 Plug (B) in heater hose (Sec 2)

Fig. 2.3 Plug (D) in expansion tank (Sec 2)