Thermal isolation of cooling circuits with a common degas bottle filling port

A multi-circuit degas bottle for a vehicle cooling system comprising a first cooling circuit having a first operating temperature range when the vehicle is in an operational state, and a second cooling circuit having a second operating temperature range when the vehicle is in the operational state, the first operating temperature range being higher than the second operating temperature range, the multi-circuit degas bottle comprising:

• a first chamber operably coupled to the first cooling circuit;
• a second chamber operably coupled to the second cooling circuit;
• a fill port operably coupled to the second chamber;
• and
• a flow restrictor disposed at a divider separating the first chamber and the second chamber,
• wherein the flow restrictor is configured to open to enable cooling fluid provided via the fill port, when the vehicle is in a non-operational state, to flow from the second chamber to the first chamber and configured to be closed when the vehicle is in the operational state to prevent the cooling fluid from flowing between the first and second chambers.