2006 Mercedes SLK-Class Owner's Manual - Page 315

Operation Engine compartment The coolant expansion tank is located on the passenger side of the engine compartment. Using a rag, turn cap 2 slowly approximately one half turn counterclockwise to release any excess pressure. Continue turning cap 2 counterclockwise and remove it. The coolant level is correct if the level for cold coolant: reaches marking bar 3 in expansion tank 1 for warm coolant: is approximately 0.6 in (1.5 cm) higher Add coolant as required. SLK 350 (example) Battery Your vehicle's battery is located in the engine compartment. The battery should always be sufficiently charged in order to achieve its rated service life. Refer to the Maintenance Booklet for battery maintenance intervals. If you use your vehicle mostly for short-distance trips, you will need to have the battery charge checked more frequently. When replacing the battery, always use batteries approved by Mercedes-Benz. If you do not intend to operate your vehicle for an extended period of time, consult an authorized Mercedes-Benz Center about steps you need to observe. Replace and tighten cap 2. For more information on coolant, see "Coolants" ( page 453). 1 Coolant expansion tank 2 Cap 3 Marking bar in the expansion tank 314