The coolant in the Volvo 850 prevents engine fluids from turning into ice in freezing weather as well as keeps fluids from boiling in extreme heat. The coolant stabilizes the temperature of engine fluids during extreme weather conditions. Normally, the coolant does not need to be changed; but if you have a leak, you will need to patch the leak and check the coolant level to determine how much coolant to add.
Turn the 850's engine off and open the hood. Wait five minutes for the engine to cool down.
Remove the cap from the expansion tank in the engine compartment.
Move the temperature adjuster control to the maximum heat setting. Open the drain cocks in the engine compartment. There is one on the rear left of the engine block and one at the bottom right corner of the 850's radiator.
Place a drip pan under the radiator then disconnect the lower right radiator hose to drain the fluid.
Reconnect the hose and close both of the drain cocks.
Pour coolant into the expansion tank to the "MAX" line. It may be easier to use a funnel.
Start the 850's engine and run the vehicle until it reaches normal operating temperature. Check the coolant level. Make sure it is at the "MAX" line. Close the hood.
