alternator belt MERCEDES-BENZ R350 2008 W251 Owner's Manual

444 Practical hints
What to do if …
Symbol messages
Display symbolDisplay messagePossible cause/consequencePossible solution
òReplace air filter.The air filter is clogged.Have the air filter checked by an autho-
rized Mercedes-Benz Light Truck Center.
#The battery is no longer charg-
ing.
Possible causes:

alternator malfunctioning

broken poly-V-belt
Do not forget that the brake
system requires electrical
energy and may be operating
with restricted capability.
Considerably greater brake
pedal force is required and the
stopping distance is increased.
Stop the vehicle in a safe location or as
soon as it is safe to do so and check the
poly-V-belt.
If it is broken:
Do not continue to drive. Otherwise
the engine will overheat due to an
inoperative water pump which may
result in damage to the engine.
Contact an authorized
Mercedes-Benz Light Truck Center.
If it is intact:
Contact an authorized
Mercedes-Benz Light Truck Center
immediately. Adjust driving to be
consistent with reduced braking
responsiveness.

526 Technical data
Layout of poly-V-belt drive
R 320 CDI 4MATIC
1Coolant pump
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Idler pulley
8Generator (alternator)R 350, R 350 4MATIC, R 550 4MATIC
1Idler pulley
2Idler pulley
3Automatic belt tensioner
4Power steering pump
5Air conditioning compressor
6Crankshaft
7Coolant pump
8Generator (alternator)