2009 Volvo XC90 Owner's Manual - Page 206

09 Maintenance and servicing 09 Working on your vehicle Belt check Check the belt regularly to make sure it is in good condition and is clean. A worn or dirty belt can cause poor cooling and low alternator output as well as impair the operation of the power steering and the air conditioning unit. and the expansion tank during engine warm up and cooling. Changing coolant Normally, the coolant does not need to be changed. If the system must be drained, consult a trained and qualified Volvo service technician. Do not top off with water only. This reduces the rust-protective and antifreeze qualities of the coolant and has a lower boiling point. It can also cause damage to the cooling system if it should freeze. Top off with Volvo Genuine Coolant/Antifreeze only (a 50/50 mix of water and antifreeze. NOTE The drive belt is equipped with a self-tensioning mechanism and requires no adjustment between changes. WARNING The engine must not be running when this check is performed. CAUTION Check coolant level The cooling system must be filled with coolant and not leak to operate at maximum efficiency. Check the coolant level regularly. The level should be between the MAX and MIN marks on the expansion tank. The check should be made with particular thoroughness when the engine is new or when the cooling system has been drained. Do not remove the filler cap other than for topping up with coolant. Frequent removal may prevent coolant circulation between the engine The cooling system must always be kept filled to the correct level. If it is not kept filled, there can be high local temperatures in the engine which could result in damage. Different types of antifreeze/coolant may not be mixed. WARNING Never remove the radiator cap while the engine is warm. Wait until the vehicle cools. 206