Removal and installation the water pump (BMW 5 Series E28)

The engine must cool down completely before starting work.

If your vehicle's radio is equipped with an anti-theft system, make sure you enter the correct code before disconnecting the battery.

If the instrument cluster displays the wrong language after connecting the battery, refer to Section Anti-theft audio system and instrument cluster language, which describes the procedure for installing the required language.

Removal

1. Disconnect the negative battery cable.

2. Drain the cooling system (see chapter Routine car maintenance). If the cooler is relatively new or in good condition, save 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 the drive belts (see chapter Routine car maintenance).

5. Where present, loosen the clamps and disconnect the hoses from the water pump. If they are stuck, grasp each hose at the end with water pump pliers, gently twist 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 on the end of the water pump shaft (see section Checking the operation, removing and installing the engine cooling fan and its drive clutch).

7. To remove the water pump, follow the procedure appropriate for your engine type.

M10 engines

Give me seven bolts (indicated by arrows), and remove the water pump.

M20 engines

1. Remove the distributor cap and high-voltage wires, spark plug rotor and dust shield (see chapter Routine car maintenance).

2. Where provided, remove the distribution sensor (see chapter Ignition system).

3. Remove the upper timing belt cover (see Part Repair work carried out without removing the engine from the vehicle).



4. Loosen all three water pump mounting bolts. Remove the top and right bolts, but DO NOT remove the bottom bolt.

5. Turn the pump down and remove the spring and pin of the drive belt tensioner.

6. Loosen the last water pump mounting bolt and remove the pump.

Leave the tensioner bolt tight. Be careful not to move the camshaft sprocket, as if the valves move, this can cause serious damage.

M40 engines

Loosen the mounting bolts and remove the water pump. If the pump is stuck to the cylinder head, insert two bolts into the special ears at the top and bottom of the pump and tighten them evenly to remove the pump from the head.

Installation

1. Clean the engine bolt threads and holes 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 old gasket material from the engine using a special scraper.

4. Clean the mating surfaces of the water pump.



5. On M40 engines, install a new sealing ring on the pump.



6. Install a new gasket on the pump and slide the pump up toward the engine.



7. Insert a pair of bolts into the pump mounting holes to hold the gasket in place.

8. Carefully secure the pump and gasket to the engine, tightening the bolts by hand.

On M20 engines, hand tighten the bottom bolt, then rotate the water pump into place and install the drive belt tensioner spring and pin.

9. Install the 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 turn at a time. Do not overtighten them, as this can deform the pump.

10. Install all components removed earlier to provide access to the pump.

11. Fill the cooling system and check the tension of the drive belt (see chapter Routine car maintenance). Start the engine and check for leaks.

This publication was borrowed from an online resource BMWMan.ru