on the sierra rack you could put the pipes on either way in some cases and it wouldn't make a difference, but in some it did which led to problems

the way you have described it, you have air in the system which we all seem to agree on

all we have to do now is figure out where the air is coming from, either air stuck in the system from when you changed it, air coming from a leak in the pipe, highly unlicky as it would leak from said hole, or air from a split in the rack, which would mean the bellows on one end will be full of fluid and it may only do it when you turn the wheel one way