provide reliable cooling system protection. In special cases (commercial-vehicle engines, no antifreeze
specification) coolant additives can be used that are primarily corrosion protection additives. In this case
item 2.3 is valid.
As an exception, if neither anticorrosion/antifreeze agent conforming to Sheet 325.0 nor coolant additives
without addition of antifreeze conforming to Sheet 312.0 are available, proceed according to point 2.4
(exception: OM 500 and OM 900). The systems described under items 2.2/2.3/2.4 are not compatible
with each other. It is recommended to mix the entire coolant quantity outside the engine.
2.1 Anticorrosion/antifreeze agent for passenger-car engines
Alongside the correct constitution of the cooling water (point 1.2.2), care must be taken to ensure that
only anticorrosion/antifreeze agents as approved for all engines in accordance with Sheet 325.0 are used.
These products serve to guarantee that, in particular, an effective protection against corrosion is provided
for all light-alloy parts in the cooling system and they are also specified for all passenger-car engines.
In order to ensure that the protection against corrosion is effective, the anticorrosion/antifreeze agent must
remain in the cooling system throughout the year - including when in tropical climates - and regardless of
the operating conditions. In countries with high outside temperatures this is also important in terms of
raising the boiling point.
In the event that these regulations are not observed the cooling system may suffer from damage by
corrosion. As a consequence of corrosion deposits there is a danger that ducts in the radiators (engine
overheating) and heat exchangers (poor heat output) get plugged up thus causing damage to the engine.
As a result of the optimizations we have carried out on the system of engine/coolant/cooling system, in
the majority of our newer passenger cars, a replacement of coolant is not necessary until reaching 15
operating years or 250,000 km (whichever comes first). This may not apply to some models; in these
cases the maintenance booklet will stipulate another regulation.
2.2 Anticorrosion/antifreeze agent for commercial-vehicle engines (normal case)
(not: BR 600, BR 100 and BR 200)
The coolant in commercial-vehicle engines is made up of both water and anticorrosion/antifreeze agent
(refer to item 1.1.1) and as such offers ideal protection against corrosion and cavitation.
All the approved products on the Sheets 325.2, 325.3 or 325.0 which are part of the Specifications for
Operating Fluids can be used to select an anticorrosion/antifreeze agent. However, it should be noted that
passenger vehicle engines built into commercial vehicles must be filled like passenger vehicles (e.g. OM
601 in T1), i.e. a product conforming to Sheet 325.0 and 326.0 must be used.
Products that are not listed in Sheets 325.0 and 326.0, or 325.2 and 326.2, or 325.3 and 326.3 are not
approved and are therefore not to be used under any circumstances.
Anticorrosion/antifreeze agents or coolants conforming to Sheet 325.3 or 326.3 may be used for
longer than other products due to their composition. The change interval is set at 5 years (refer to
2004 Mercedes-Benz ML350
1998-2005 GENINFO Overall vehicle - 163 Chassis
me
Saturday, October 02, 2010 3:47:57 PMPage 524 © 2006 Mitchell Repair Information Company, LLC.
