Installed a Raptor Lift Pump over a year ago.. I remember once somebody saying to me around that time that Cummins recommended 16psi to the VP44 never to go lower than 5psi. The raptor has always showed 14psi with momentary drop to 12psi if you're in the throttle.. I had the truck on the interstate today for about a 90 min ride one way. At the end of the outbound trip, pressure dropped to 13 with dips to 11.. The inbound trip showed cruising at around 80mph at 12psi with dips to 10psi.. Idiling at 13psi.. I thought about changing the fuel filter to see if that helped.. Im curious if this is typical of the Raptor or should I bump its pressure up a little. I can't find anything online saying what the pressure should be.. This truck runs a mixture of Ultra Low Sulfer and Bio Diesel (PA fuel is bio).. I was also wondering if anybody has installed an inline filter between the fuel tank and the Lift Pump. Always seem to get good information from this forum.. Thanks in advance for any replies...

 

you are correct on the 16 psi and the 5 psi. install the filter after the raptor and before stock. wix base 24770 wix filter 33674 you will never have to change the stock filter again. but nothing is going to extend the life of the vp44. we run some raptors, it is a well built gear pump i have not driven the vp44 trucks with the raptor to know if it varies but when i installed one the way the pressure relief worked i do not see how it could vary.

 

Those pressures are fine......but go ahead and change the filter. What FASS used to recommend for their pumps (don't know if they still do) was when pressure dropped slightly (as it did in your case), change out the filter. I change mine once per year.....just because.