Engine/Transmission (1994 - 1998) Lift pump questions???????

[jpogue]

My 96 has 135,000 miles on it now. I changed the fuel filter yesterday and I noticed some small but visible metal flakes in the fuel that came out of the filter. I changed filter about 5,000 miles ago when I started running B100. There aren't a lot of metal flakes and they don't stick to the tip of a magnetized screw driver. Could this be from lift pump? It's not leaking anywhere but any metal flakes in any type of engine area scares me. Last time I changed rear diff fluid I noticed a lot of metal flakes and when I went to wipe bottom of housing I found big chunks. Any help on where the metal flakes in fuel might be coming from would be greatly appreciated.

Thanks