I have a P-500 which does not want to start by itself.  If I bang on the pump it will start working and stay working until I turn power off to it and let it sit for a few days.  When I try to start it again, I have to jump start it by banging on it. 

Is there any way to service this pump or oil it or rebuild it somehow?  If not, can you suggest a replacement pump and provide a link for something that would be a direct replacement?  Are these pumps universal and/or do I need to replace it with the exact make/model.

It supplies a single Marine Air Systems Vector Series self contained combined heat/ac unit with a digital passport II control board on a 28 Wellcraft martinique. 

Is this a common problem?  Someone told me it seems like something is sticking. 

Thanks in advance for your help.

Did you ever get this pump?  I am interested in buying one to install before spring launch and was wonderinf if you have one and/or will you have them before spring time?

I also just wanted to double check with you regarding repair.  Someone at the marina told me you can take the pump apart and clean it which sometimes does the trick.  They said the pump sometimes has the magnet stick?????  Does this sound like a possible solution to the problem or is it not worth it and do you know what the guy was referring to?

Hate to second guess your response but just wanted to be 100% sure and would be willing to give a repair a try before spending the money for a new pump.  The pump is over 10 years old but is on a boat with low hours and not much use.

Thanks again for your help.