I meant, to say " push in, not pull out." I've moved many trailers with my m931 both civy, and military. I found that it is easy to get the lines mixed on the civy trailers. Especially on a well used trailer where the glad hands paint is gone or the air line tags are missing. Sometimes I'd have to swap the lines to get them to work right. Trailers with airbags may a long time to fill.