OK chaps I am in need of a lesson. How does an aircon pump as filled to a B6 2008 2.0 TDI 16 Valve Passat actually work. I think the end in the middle is supposed to stay still until the aircon is on. What I dont know is a few things lol How is the 3 vane clutch is pulled in...I can only assume its Hydraulic as I cant see how an electro magnet would work in this type. If the Pump is stuck on would/should the aircon be on all the time. (It was not working even when filled with Gas) Chap filled it with Gas .we tested it and it did not get cold so he took it all back out again so I could take the pump off. Upon taking the pump of we can see the inner and outer were seized together. Even now they are not seized together it is hard to push in and out (leading me to think its hydraulic) Finally the Bolt had come out of the end of the pump and reading on line it seems to be a common thing.....not nice when you have to remove the damn front of the car to change the pump.... I stand by to be educated... Thanks in advance.