I was having an issue with bubbles in the luer lock too. I called Tandem when my frustration was at it's breaking point. It was suggested by a customer service rep (who is also a T:slim user) that when you begin to start the priming of the tubing, you keep the luer lock and tubing disconnected until the insulin forms a bubble on top of the luer lock, while holding the luer lock straight up in the air. All the bubbles get a chance to be released into the air and don't collect inside the luer lock. When the "bubble" looks like it is about to break open, connect the tubing and continue with the priming.
I have to admit, it has been working like a charm! I flick the lock every few seconds (after the tubing is connected) so that any other bubbles can be primed out and don't get the chance to form into a larger bubble.
I've tried all the other suggestions but this one has worked consistantly. I hope this helps!
