I'm replacing my fuel lines and found a capped banjo fitting on the intake of the stock fuel filter housing. It looks to me as if it were brazed shut. Any ideas as to what it's there for?

I would suspect it was there for a lift pump fuel pressure test port or for an in-cab lift pump fuel pressure gauge / warning light system.

 

- John

 

I guess I was kinda thinking the same thing. I do have an in cab warning might that runs off a T in the fuel line between the factory filter housing and the vp44. But it evidently doesn't work as I found today that the ground wire isn't even hooked to the sensor.