Cat C7 secondary fuel filter

We deal with a lot of diesel engines on our farm and the new diesels seem to handle air in the system than the old diesels. If we have trouble priming an engine the quickest we to prime them is put a little air pressure in the fuel tank. That being said we have one piece of machinery that didn't want to prime after fuel filter changing and we put some air pressure on the tank and got it bled out. But later found out the fuel pump was weak. If the fuel pump was good it would have primed on it's own. The C7 is the 330 hp version. Evidently the fuel pump is good on this one. It started immediately and at an idol for a while if never even run rough. I opened the opening under the rear bedroom and it's a big opening that I can stand right on the engine and the filter is a piece a cake as it's located at the top of the engine. It was the first time I opened the cover and setting the valve lash will be a piece of cake and cleaning the radiator will be easy. My radiator looked very clean.;)