bypassed. i know the 10s dont filter as well as the 2s. i guess you could say i was also testing the 10 to see if the small difference in fuel flow thru it made any difference as well. but i have a standby 2mic and 10mic on the shelf in the garage as well...just in case

 

Yeah the factory fuel filter is like an 8 micron and with a 10 you are letting more particulates into your fuel system. Put the 2 on it and run diesel additive. I used to live in Iowa and Eastern Montana and my truck has seen up to 20 below for weeks on end and never had a gelling issue. JMO though

 

well i run additive in the winter and last year holy ****!!!for like a week straight my pickemup was gelled up and so were both our volvo and our mack. they sat inside for 4 days straight just to unthaw. it was cold! but yes i believe i should have the 2 on there. just thought i would try a ten for a week or so.

 

10 micron filters are probably okay on your truck. VP44 trucks are not as finicky with filtration as the common rails. 2 microns is obviously better for everything involved but 10 shouldn't hurt anything.

I would say it's either the VP or your split line. I would check all of the fittings from the tank to the injection pump. Just mix some dish soap with water in a squirty bottle and while the truck is idling spray each fitting including the area around the sending unit. See if you are getting any bubbles.