Just noticed my IP is leaking. It's coming from the back of the pump, out of a small rubber hose that's pointed down...I'm guessing this is an overflow valve of some sort? Not sure. What is it and why is it leaking? Thanks.

 

I assume you are talking about the vent for the AFC housing. If it is in the truck with the Denny T pin it could be that the extended travel of the modified pin is causing the o-ring around the follower pin to leak (the follower pin is slightly barrel shaped) , and putting a stock AFC pin in might fix the problem. If not, you need to replace that o-ring in the pump cover assembly. The cover has to come off the truck to do this.

Look in the sticky's and decide if you want to do it yourself or send the pump out to a pump shop.