2011 Mercedes GLK-Class Owner's Manual - Page 300

298 Service products and capacities Coolant Important safety notes The coolant is a mixture of water and antifreeze/corrosion inhibitor. It performs the following tasks: Ranti-corrosion Rantifreeze Refrigerant of the air-conditioning system The air-conditioning system is filled with R134a refrigerant and a special PAG lubricant. protection protection Rraising the boiling point The cooling system is filled with coolant at the factory which contains antifreeze/corrosion inhibitor that ensures protection down to approximately -35 ‡ (-37 †). ! Never use refrigerant R 12 (CFC) or mineral lubricants. Otherwise, you could damage the air-conditioning system. Technical data Brake fluid G Warning! The brake fluid constantly absorbs moisture from the air; this lowers its boiling point. If the boiling point of the brake fluid is too low, vapor pockets may form in the brake system when the brakes are applied hard (e.g. when driving downhill). This would impair braking efficiency. You should have the brake fluid renewed at regular intervals. The brake fluid change intervals can be found in the Service Booklet. ! Only add coolant that has been premixed with the desired antifreeze protection. You could otherwise damage the engine. Further information on coolants and on filling can be found in the Mercedes-Benz Specifications for Service Products, MB Approval 310.1, e.g. on the Internet at http://bevo.mercedes-benz.com. You can also consult an authorized MercedesBenz Center. ! Always use a suitable coolant mixture, even in countries where high temperatures prevail. Otherwise, the cooling system will not be sufficiently protected from corrosion, and the boiling point will be too low. If the coolant has antifreeze protection down to -35 ‡ (-37 †), the boiling point of the coolant in the pressurized system is approximately 266 ‡ (130 †). Your vehicle has a range of aluminum components. Use of aluminum components in the engine make it necessary to specifically match the antifreeze/corrosion inhibitor in these systems in order to protect the aluminum parts. Using other antifreeze/ corrosion inhibitors without these characteristics affects the service life. The coolant must be used throughout the year in order to maintain the necessary corrosion protection and provide protection from Only use brake fluid approved by MercedesBenz. Information about approved brake fluids can be obtained from any authorized Mercedes-Benz Center.