Checking and topping up other fluids and lubricants
Checking the coolant level
WARNINGThe engine cooling system is under pressure. Therefore, only open the cooling system cap when the engine has cooled down. The coolant temperature gauge must then show a temperature below 40 °C. Otherwise, you could be scalded by hot coolant spray.
. Otherwise, you could
be scalded by hot coolant spray.
coolant level while the coolant temperature is above 40 °C, you risk damaging
the engine or the engine cooling system.
). If you check the coolant level while the coolant temperature is above 40 °C
, you risk damaging the engine or the engine cooling system.

- Park the vehicle on a level surface.
Check the coolant level only when the vehicle is level and after the engine has cooled down.
- Turn the key to position 2 in the ignition switch.
- Check the coolant temperature gauge in the instrument cluster.
The coolant temperature must be below 40 °C.
.
- Turn the key to position 0 in the ignition switch.
- Slowly turn the cap 1 counterclockwise by half a turn and wait until the pressure has dropped.
- Continue turning the cap 1 counterclockwise and remove it.
The coolant level in the expansion tank 2 is correct if it reaches mark 3 when the engine is cold.
- If necessary, top up with a coolant tested and approved by Mercedes-Benz.
- Reinstall the cap 1 and turn it clockwise until it stops.
For more information on coolant, see.
Topping up windshield washer fluid and headlamp washer fluid
WARNINGWindshield washer fluid/antifreeze is highly flammable. Therefore, do not spill windshield washer fluid/antifreeze onto hot engine components, as it may ignite and burn. You or other persons could be seriously burned.

- Opening: lift the cap 1 by its tab.
- Add the prepared windshield washer fluid.
- Closing: place the cap 1 back on the filler opening, then press it down until it clicks fully into place.
The windshield washer and headlamp washer are both supplied from the windshield washer fluid reservoir.
For more information on windshield washer fluid/antifreeze, see
Test yourself
A quick Mercedes-Benz B-Class quiz: every answer comes with an explanation and a link to the manual page.