Fuel pressure drop after pre-pump filter change.
97 PSD w/ Dieselsite CPR fuel. Just bought this truck and it has the CPR fuel system with an oversized separator that takes the Dahl 101 filters. I changed the pre-pump filter for the first time today. After I put the separator back on I tried to prime it by opening the valve and it only partially filled. So, I cranked the truck and watched it fill. I then watched the fuel pressure at the regulator and in the cab fluctuate for about 1 minute before settling at about 25 psi. It's usually set at 65 psi. It is idling fine, I'm guessing I have air in the system, but I thought the CPR system would remove it automatically. Do I need to let it run for a bit to purge the system? There are no leaks anywhere. It's my first diesel, can't figure it out.