Raw water pump clarity

[Ironrogue]

I've been troubleshooting a water intake issue and am hoping to clarify a point with the raw water pump and housing.
Throughout my research via internet, it has been stated that movement in the raw water pump inlet or outlet fittings indicates the need for pump unit replacement. I wish to have clarification regarding this. In my case, I find that the plastic type inlet and outlet fittings can both rotate in their respective brass bores, albeit with a pretty good amount of resistance as though the seal is via an oring or something similar. Can someone verify if this is the correct acceptable movement or is it expected to be completely rigid? These fittings are by no means loose, but as said previously, can be rotated with effort. It does not seem that this could be a source of sucking air but I am trying to do as much indestructive testing as possible. I am currently assembling a list of items referred to in the VP Overheat Diagnosis document in the stickies for further testing and trying to rule out things one by one. In addition, as far as I can tell, there is, nor has been, any evidence of any sort of rubber cap associated with the impeller. Does this sound normal? I've read reference to such a cap or caps.
Engine is 2004 4.3GL-D sn 4012112453
Engine has an indicated @120 hours

 

[dypcdiver]

Re: Raw water pump clarity

I am not sure how the plastic pipes are secured, but suspect glued, an "O" ring would seem an expensive way to do it, in addition there is no need for them to be able to rotate. If you are worried you can always wrap some self amalgamating tape round the plastic pipe to brass joint as a temporary test.
The cap is just a rubber disc that fits into the end of the impeller, I have 2 of them that came out of kits some years ago but I have not seen any in the recent kits, so can only assume VP don't think they are needed any more.

 

[Ironrogue]

Re: Raw water pump clarity

Thank you for your input on both points.
I am hopeful that I may have found a portion of the water intake fault.
I am able to view a portion of the water passage seal ring through the inspection port of the outdrive. I imagine this should not be possible and am currently pulling drive to investigate.
After correction I will test and if flow does not improve, will proceed with temporary seal of pump inlet/outlets as dypcdiver describes.
I will, for now, not give much thought regarding impeller caps.
Again, all replies are appreciated and given credence. Thanks to all!