Seawater Pump Issues

[lucky7's]

I have a 2002 Merc 6.2 mpi bravo that has the bronze housing seawater pump. Recently I have developed a water supply problem and it seems that the pump is not pumping enough water and also the suction is not as good as it used to be (when I flush the engine I have to give a little gas to get it to pickup water and used to not have to do that). I replaced the impeller and this did not fix the problem. The old impeller was in good shape and no broken blades. The back plate of the pump housing does have some wear grooves in it, which is what I think the problem is. I have about 500-600 hours on this pump, is it time to replace? What is the life expectancy on these pumps with regards to the housing? Does anyone make a repair kit for this?

Thanks,

FT