BMW 5251 Service Manual page 48

020-1 6
Maintenance
loose, hose is damaged, or connection is dirty or corroded.
Dried coolant has achalky appearance. Hoses should be firm
and springy. Replace any hose that is cracked, has become
soft and limp, or has been contaminated by oil.
4
As a preventive measure, replacement of the cooling system
hoses every four years is recommended. The illustration
shows examples of damage to coolant hoses. Any of these
conditions is cause for replacement (illustration courtesy of /
Abrasion Damaged Hose Heat Damaged Hose
1
Gates Rubber Company, I ~ c . ) .
Engine drive belt, replacing
Drive belts and pulleys transfer power from the engine crank-
shaft to various accessories.
E39
models use two polyribbed
(serpentine) belts:
The outer belt turns the N C compressor.
0
The inner, longer belt turns the alternator (generator), cool-
ant pump and power steering pump.
Inspect drive belts with the engine off. If the belt shows signs
of wear, cracking, glazing, or missing sections, it should be
replaced immediately. To reduce the chance of belt failure
while driving, replacement of the belts every four years is
recommended.
WARNING
-
Observe care when replacing belts. Personal injury could
result if a tensioner springs back into position uncontrolled.
CA UTIOI\C
Mark drive belt rotation direction if removing and reusing an
old belt.
NOTE-
When belts are replaced with new ones, store the old set in
the trunk for emergency use.
All models, use BMW special tools 11 5 030 and 11 5 040 to
loosen and remove cooling fan and clutch from coolant
pump.
NOTE-
32 mm cooling fan nut has left-hand threads
I f necessary, remove fan cowl from radiator.