The engine must be completely cool before starting work.
If your car's radio is equipped with an anti-theft system, make sure you have entered the correct code before disconnecting the battery.
If, after connecting the battery, the inscriptions on the instrument panel appear in the wrong language, refer to Section Anti-theft audio system and instrument panel language, for instructions on how to set the desired language.
Withdrawal
1. Disconnect the negative battery cable.
2. Drain the cooling system (see chapter Car maintenance). If the cooler is relatively new or in good condition, keep it for later use.
3. Remove the cooling fan shroud (see Section Checking the operation, removing and installing the engine cooling fan and its drive clutch).
4. Remove drive belts (see chapter Car maintenance).
5. Where available, loosen the clamps and disconnect the hoses from the water pump. If they stick, grab each hose at the end with water pump pliers, twist gently to break the sealant, then remove. If the hoses are old or worn, cut them off and replace with new ones.
6. Remove the fan and clutch assembly and the pulley at the end of the water pump shaft (see Section Checking the operation, removing and installing the engine cooling fan and its drive clutch).
7. Follow the procedure for your engine type to remove the water pump.
M10 engines
Give seven bolts (indicated by arrows), and remove the water pump.
M20 engines
1. Remove the ignition distributor cap and BB wires, ignition slider and dust shield (see chapter Car maintenance).
2. Where provided, remove the distribution sensor (see chapter Ignition system).
3. Remove the timing belt top cover (see part Repair work carried out without removing the engine from the car).
4. Loosen all three water pump mounting bolts. Give out the top and right bolts, but DO NOT give out the bottom bolt.
5. Turn the pump down and remove the spring and drive belt tensioner pin.
6. Give the last bolt of fastening of the water pump and remove the pump.
Leave the tensioner bolt firmly tightened. Be careful not to move the camshaft sprocket as if the valves move, serious damage may result.
M40 engines
Give fixing bolts and remove the water pump. If the pump has become stuck to the cylinder head, insert two bolts into the lugs on the top and bottom of the pump and tighten them evenly to remove the head pump.
Installation
1. Clean the threads and bolt holes of the engine to remove any traces of corrosion and sealant.
2. Compare the new pump with the old one to make sure they are identical.
3. Remove all traces of the old gasket material from the engine with a special scraper.
4. Clean the mating surfaces of the water pump.
5. On M40 engines, install a new O-ring on the pump.
6. Install a new gasket on the pump and slide the pump up towards the engine.
7. Insert a couple of bolts into the pump mounting holes to hold the gasket in place.
8. Carefully secure the pump with gasket to the motor by hand-tightening the bolts.
On M20 engines, hand-tighten the bottom bolt, then rotate the water pump into place and install the spring and drive belt tensioner pin.
9. Install remaining bolts (if they also hold the auxiliary bracket, make sure it is already in place by this time). Tighten them to the required torque gradually, a quarter of a turn at a time. Do not overtighten them, as this can damage the pump.
10. Install all components removed earlier to gain access to the pump.
11. Fill the cooling system and check the tension of the drive belt (see chapter Car maintenance). Start the engine and check for leaks.