I discovered this by accident when I was changing a diesel lift pump and had to find something fast to plug a leaking disconnected fuel hose. Remember anytime you are changing the pre-filter and disconnect the fuel hose coming from the tank - it WILL leak - and can leave a real mess!
Problem & Solution
Common among these chassis:
Unscrew one of your interior door lock knobs and shove it in the hose. This actually works better than any bolt and it is always "handy." Getting some fuel on it even gives you the chance to clean it! :-)