manual fuel pump

I have a 91 b2200, the fuel pump leaks only on initial start up in mornings.
Any reasons why. Thanks

Yep.Overnite everything cools down and conracts.When u start in am, pump leaks until temp and pressure rises and seals leak.It will just get worse.BJ

Mechanical fuel pump, you mean? The one that runs off of the camshaft? If so, that leak you have is a safeguard to tell you the diaphragm is bad! Replace that sucker ASAP!

Mine was bad for quit a while until I noticed the leak! I had 12 mpg!