Jeep 2007 Commander - Manual (Page 376)

Check the engine cooling system hoses for brittle rubber,
cracking, tears, cuts, and tightness of the connection at
the coolant recovery bottle and radiator. Inspect the
entire system for leaks.
With the engine at normal operating temperature (but
not running), check the cooling system pressure cap for
proper vacuum sealing by draining a small amount of
coolant from the radiator drain cock. If the cap is sealing
properly, the antifreeze/coolant will begin to drain from
the coolant recovery bottle. DO NOT REMOVE THE
COOLANT PRESSURE CAP WHEN THE COOLING
SYSTEM IS HOT.
Cooling System — Drain, Flush, And Refill
At the intervals shown in the appropriate “Maintenance
Schedule,” the system should be drained, flushed, and
refilled.
If the solution is dirty and contains a considerable
amount of sediment, clean and flush with reliable cooling
system cleaner. Follow with a thorough rinsing to remove
all deposits and chemicals. Properly dispose of old
antifreeze/coolant solution.
Selection Of Coolant
Use only the manufacturer’s recommended antifreeze/
coolant, refer to Fluids, Lubricants, and Genuine Parts for
correct antifreeze/coolant type.
376 MAINTAINING YOUR VEHICLE