Discovery I (LJ) V8-4.0L (1996)
NOTE: It is not possible to drain all coolant retained in heater system. Flush through system, after draining, by pouring clean water into the fill
tower, with bottom hose disconnected and engine drain plugs removed.
Block Drain Plugs
4. Remove engine drain plugs, one each side of cylinder block, beneath exhaust manifolds.
5. Drain coolant, refit and tighten plugs.
6. Pour correct solution of water and anti-freeze into expansion tank until radiator is full.
7. Start engine, run it until normal operating temperature is attained, topping up as necessary.
8. Refit radiator filler plug and O-ring, with new O-ring if required. Tighten to 6 Nm (53 in lb).
9. Fit expansion tank filler cap.
10. Allow engine to cool, check coolant level. Finally top up expansion tank until level reaches seam of expansion tank.