Bubbles In Clear Fuel Pipe

[westytwo]

I have been reading loads of threads about loss of power on the TDi's. One of the threads mentioned that he had air bubbles in the clear fuel line I have noticed the same thing on mine and my power loss is also intermittent. I have replaced all the small vacuum hoses to the turbo actuator aif filter box boost control solenoid etc. I have also changed my Maf and checked for movement on my actuator arm it moves approx 10 mm can be seen to move when revving the engine and also moves out when switching the engine off so I dont think the turbo control vanes are sticking. Anyway I am going to change the fuel filter and check where possible air leaks could be but how do you purge the air out of filter after replacing it. Any help would be appreciatted!!!!