N3D
This is a nice little red plastic tool that you should have if you own a later model Volvo.
. The coolant hoses attached to the heater core and to the connectors in the engine bay have an interesting lock ring design. The lock ring has to be rotated to disconnect the hose
If you do not have the same tools that the dealership service center has, you are on your own.
Some time will be spent dancing around the engine bay while attempting to disconnect the hose.
As a rule, if you use a pair of pliers or a Channel Lock tool, you will damage the connector.
If you own a later-model Volvo, you need the tool we are offering. You will receive the red tool in the picture, and this should make life easier