Hi all I had a problem with my Blackburn frame pump today.
At the end of a double century I got a flat. After fixing it I found I could not get a seal with my BB frame pump. Someone else lent me theirs thankfully.

When I got home I discovered air was leaking from between the black plastic head and cylinder. I discovered the black head assembly was lose and came right off. I eventually got it back on, kind of, but here is my problem. I don't know how to tighten it. From the main Cylinder a sliver threaded rod sticks out and is able to rotate freely in the cylinder and go in and out of it. The black plastic head has female threads and a spring sits between it and the cylinder. How can I tighten the head when the silver rod can rotate freely in the cylinder?