BMW 1989-1995 525i Service Manual page 212

170-8
RADIATOR AND COOLING SYSTEM
4. Apply pressure to pump V-belt and loosen coolant
pump pulley mounting bolts. Then remove V-belt and
remove pulley from pump.
5. Remove engine lifting bracket from front of engine.
6. Remove coolant hose from pump.
7. Remove six coolant pump mounting bolts and remove
pump. See Fig. 11 .
65 '9.CO().4· ' 5
Fig. 11. M30 engine coolant pump. Mountong bolts shown at arrows.
8. Installation is reverse of removal. Use a new gasket
and make sure gasket mating surfaces are clean and
dry. Fill system with coolant and bleed system as de·
scribed under Draining and Filling Coolant.
Tightening Torques
• Coolant pump to cylinder block . .
.. . 10 Nm (89 in-Ib)
• Coolant pump pulley
to coolant pump 10 Nm (89 in-Ib)
To replace coolant pump
(M50 engine)
NOTE -
Only replacement coolant pumps with metal impellers
should be installed. Pumps with plastic imp ellers
should not be used.
1. Disconnect negative
H
cable from battery.
COOLANT PUMP REPLACEMENT
2. With engine cold, drain cooling system as described
earlier.
WARNING -
Allow cooling system to cool before opening or
draining system.
3. Remove fan clutch assembly and fan shroud as de-
scribed below under Cooling Fan Removal and In-
stallation.
NOTE -
The radiator cooling fan nul (32 mm wrench) has tett-
hand threads.
4. Loosen hose clamps and remove hoses from thermo-
stat housing.
5. Loosen coolant pump pulley mounting bolts. Then reo
move drive belt. See Fig. 12. Remove pulley from
pump.
Fig. 12. Poly-V belt tensioner being released. Pry off tensioner cover
and then lever tensioner clockwise to release belt tension.
6. Remove four coolant pump mounting nuts.
7. Using two M6 bolts, thread them into ears on either
side of pump. Then slowly and evenly turn bolts in until
pump is drawn out. See Fig. 13.
8. Using a new O-ring. install new coolant pump on its
studs. Tighten nuts alternately and evenly until pump is
firmly seated. Then tighten nuts to their final torque.