raw water pump dripping oil?

[Glen S]

Hi all,

OK , I have 1997 7.4 MPI Bluewaters - raw water cooled. Noticed a small oil deposit under the starboard raw water pump. These are the ones that combine the fuel pump. Smelled like gear oil. Called my mechanic who said they will need a rebuild but for the moment make sure the gear oil is full by undoing the top screw and adding as needed. Easy enough. But now I am at the boat the pump only has one screw - not 2. I undid that and gas came out. Checking my manuals I have it seems to be listed as a vent screw rather than a fill and drain screw(s). Now, does anyone know, should gas come out of that screw? If so, is there somewhere to top up the gear oil? Is it OK to run? There has been very little drip out so far. Any insight would be appreciated.

Thanks,

 

[dlvwill]

Sounds to me like the fuel pump seal has failed allowing gas into the oil side. The gas is thinning out the oil and likely the cause of the leak. (The thin oil is passing the seal.) My guess would be if you replaced the fuel pump and change the oil you will have solved the problem

 

[testlab]

I have the same setup as you on my 7.4s. I was warned to keep and eye on the oil in the fuel pump as it is the leading cause of fuel pump failure on this model. There is a vent screw to bleed the fuel pump and behind this, lower down there is another screw that allows small amount of gear oil or ATF to be added.

My fuel pumps do not have the sight tubes of later models.