Air assist

I've had a recurring problem this summer with one of the pistons that drives the (left side) fly shuttle.  It goes all wimpy and won't throw properly.  Doug has changed out everything he can think of but it still won't work.  I'm getting desperate because the current warp is just a little too wide for me to comfortably hand throw, otherwise I'd just use a hand shuttle.  We *think* the problem was caused by a lack of oil in the system but the oiler seems to be working properly now and it still isn't throwing.  At this point any suggestions would be welcome.  Doug is right now going over the whole air system checking for air leaks and is goiing to try swapping parts around to see if he can isolate the problem but.....

cheers,

Laura