502 mpi fuel pump oil change....
 

There has been a lot of talk on here lately about the fuel pumps. I have owned my rig for about a year and have not changed this oil. I want to do it this week before going out this weekend. I have one plug on the side of it that has a sticker to "see owners manual." The manual i don't have. So i will get a small hose and suck this oil out, prolly won't get it all out though i'm sure. What oil does mercruiser want to go back in, how much oil should go back in, and do you fill it till it starts to dribble out the plug?

Ryan

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I didn't think there was oil in the fuel pump to change.

502mpi should have an electric fuel pump. Do you have a mechanical one on your seapump also????

griff Ithink that if what he was talking about, same setup I have.

I have always changed mine by pulling the whole assembly off the motor so I can chnage the impeller and the pump oil at the same time. It does not take much to pull the assembly off the motor and makes getting the seaawater pump a HELL of a lot easier to get together.

Christian

Yes, I have the mechanical fuel pump mounted on top of my sea water pump. It has the scew on the side. Can someone give me the particulars on what and how much oil.

Do as christian said above and remove the entire assembly. Thats the way I always did it on my other boat. I would be able to get 90% of the lube out by leaving 1 bolt on the bracket and rotating it to dump out the lube. You can only suck out about 1/4 of whats actually in there, believe me, I tried.

It only holds about 3-4ozs of lube. Use Merc Hi Perf gear lube aka drive lube. Refill it till its starts coming out the hole with it mounted.

Before i go ripping this apart, i'm curious. What keeps the water from getting into the oil, and what seals the cam from the oil?

So are you saying, disconnect the fuel lines, water lines, and take the whole sea water pump/fuel pump and put it on the bench?

Yup :)

I disconnect the fititngs at the pump which are flanged and at the sperator and remove the seprator (2 nuts) just to give myslef more room to work. Disconnect the water hoses from the pump housing and undo the bolts holding the assembly to the motor mount (do not forget to loosen the belt, it make shtings easier) and I pull the whole assembly out and put it on the bench. There is a gasket that goes bewteen the fuel pump and the water pump (the gaskets are a couple of bucks each, I bought a 5 pack on-line)

Disassemble the pump from the water pump housing keeping the hosuing upright to not dump the oil out. When you pull the fuel pump off you will see where th eoil goes and can check for contamination. I dump the oil in a grease can and clean up the mating surfaces and reassemble after filling with hi-perf gear lube up tot he level plug)

While the mess is out of the boat take the time to inspect the impeller an dhousing and replace if necessary (i change mine every year so it is routine maintinace for me)

Assemble it together on the bench, clean it up nd re-install in the boat and voila'

So to keep the oil from all pouring out when your not ready to, take apart with the sea water pump above the fuel pump, correct?