Is there some special trick to those fuel line clamps?

Spent the day working on the project and replacing the fuel lines was next on the list.

I'm wondering if there is some special trick to getting the clamps that hold the fuel/brake lines back on the car. Of the 5 clamps, the 3 under the car seemed to go back on with a little force. But the two in the front wheel well aren't playing nice. Spent considerable time trying to apply pressure and use an allen wrench but cannot seem to get the white caps to grab the threaded posts.

Anyone got any better ideas?

 

The threads inside the white caps are probably stripped. Mine stripped out when I looked at them too hard. Checked yours?

 

They don't appear to be stripped as I can get them on the posts under the car, just not on the posts in the wheel well. I guess I could order some new ones...