[Woodyboat]

Yup, that mushroom shaped copper/brass thingy is the Thermal Expansion Volvo. ...er VALVE. LOL It's often just shortened to TXV. The capillary tube will have a bulb on the end of it that gets fastened up against one of the lines of the evaporator. It's really important that that bulb makes a very good contact with the tube that it is fastened to. I have always used a small hose clamp on it to make sure - which is way better than whatever I've ever seen any factory use. Anyway, it just gets attached to the side of the tube so that it can sense the temperature and adjust the TXV accordingly. So, go get yourself a little hose clamp... unless of course, it's already connected for you.