2012 Maxforce 13 aeration in fuel primer bowl

I have a problem with my 2012 Max 13.
I can see aeration in the fuel primer bowl. It seems to happen every few seconds (cycling), while idling. I will set the cruise at 900-1000 rpm and watch it aerate. There are a few bubbles in the filter bowl as well. I have replaced the filter and the big o-ring. The truck has low power at higher speeds but the low end is Ok. If there was a fuel pump problem would it aerate before the fuel pump. There are no fuel leaks and the truck starts right up but has hesitation when throttling. Any help is appreciated.

 

Thank You! I will report back later.

 

I have replaced all of the o-rings, the big o-ring and the threaded ring on the fuel filter. I have tightened the boss threaded fittings on the primer bowl and inspected everything for cracks. i don't have a clear tube troubleshooting tool but I think I have seen some improvement after removing and re-installing the fitting on the passenger side fuel tank, (forward port). When I idle up the truck I get a lot of bubbles. You can hear the truck surging every few seconds and see lots of bubbles in the bowl when the truck surges .
What would you do now?

 

Quick update... It looks like its coming from one of the hoses that go from the passenger side fuel tank to the bottom of the fuel filter. I will have to take out the dog house to get to them because they run over the top of the transmission.

 

It was not a fuel line. I put together a a clear hose and I have eliminated the incoming and return lines on the filter housing. I cannot see any air bubbles on those lines but I get some bubbles with a clear line connected from the filter housing going to the primer pump. So it has to be leaking in the housing assembly right? And possibly the primer pump also. I took the housing apart, replaced the bottom o-ring, the check valve, the o-rings on the return line fittings but but not the o-ring on the bottom plug, ( it seemed to be ok). I plugged the drain valve. It has a new plastic bowl housing and ring. I have to be missing something. It pulls a lot of air in at higher rpms.
I am at a loss. (no bubbles on the input side).
Any thoughts Heavy D ?

 

It's the Davco 382 and my problem is the housing. I used some clear tubing from one of the fuel tanks to the fuel primer and there were no bubbles in the primer bowl. The engine hesitation was gone and it sounded much better.
I also rigged up a clear hose on the end of the line that feeds the filter housing coming from the trucks normal fuel feed hoses. No Bubbles.
I also replaced the trucks fuel return hose with a clear one, the short one that goes into the filter house. No bubbles.
So its the Davco 382 which has a new top bowl and bottom ring seal.

 

Help please, I am missing something here.
I have a clear line running from the output of the filter housing to the fuel primer and another clear line going from the primer to the fuel pump.
There is a lot of air coming out of the filter housing.
I can take fuel input line to the Davco filter housing and plug it in to the fuel primer. (No air bubbles, the engine hesitation is gone and the engine sounds better).
I have done everything I could do to seal any leaks on the filter housing but it always generates air bubbles. I have even changed the filters and the filter brand.
I was thinking maybe the housing is causing cavitation so I even removed the check valve but that did not help.

Finally I removed the filter and filled the bowl to the top with fuel. Now I cannot see any air coming out of the housing but some air is showing up coming out of the primer. But not near as much as before.
Is my fuel pump pulling so hard it is causing cavitation?
What am I missing?