16' F350 6.7 Diesel

Is there a need to re-prime the Fuel System after taking a Fuel Sample from the Frame mounted Fuel Filter. (yellow ****) ?
How much Fuel do you drain for your average Sample ?
I've never done this.
My dealer does this (I've watched them) on my truck when I take it in for service.

I've always had excellent service from Gator Ford in Tampa.
They are a Ford dealer, but only sell Ford Trucks at this Dealership.

 

No for fuel sample as long as you only drain 8oz of diesel.

You only need to drain a few ounces as the water will be in the bottom of the fuel filter.

 

I'm pretty sure the yellow **** is used to drain water from that filter housing. The owners manual says to drain it every oil change or when the light comes on. From what I have read about fuel contamination on the 6.7L, I'm going to keep a really close watch on it.

 

The manual recommends a monthly check. I wouldn't go much longer than a month either.