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Time to start prepping for the season.
Posted: Wed Mar 07, 2012 12:19 pm
by boatsnbars
Heading to Florida for the weekend. When I get back I'm going to start working on the boat. First project is rebuilding both raw water pumps. The engines are 1996 Mercruisers with belt driven pumps that the fuel pump bolts on to, there is a little oil reservoir on the top. I am going to replace all the seals and bearings as well as the impeller and wear plates. Has anyone else done this?
Posted: Wed Mar 07, 2012 3:30 pm
by jddens
I've done mine on my Merc's but they sound diff than yours. I've been re-powered so not sure of the exact year but around 2000. Mine a 330hp 350's. throttle body. My raw water pumps mount in front of the water pump....don't know about a oil reserve on a raw water pump, mine don't have that.....I replaces one pump completely, didn't like the bearing or shaft, the other just got a new impeller.............John
Posted: Wed Mar 07, 2012 4:29 pm
by rbcool
Fuel pump bolts onto the water pumps??
Ron
Posted: Wed Mar 07, 2012 7:17 pm
by prowlersfish
Sounds crazy but that what merc did when GM stopped machining their blocks for a fuel pump . Crusader went with electric pumps
Heres a water pump , you can see were the fuel pump bolts up
http://www.ebay.com/itm/Mercruiser-Brav ... 0127511467
Posted: Wed Mar 07, 2012 9:13 pm
by Big D
Ya they are an additional pain when doing a pump rebuild. You have to disconnect fuel lines etc. If you do regular maintenance on your pump as you should; at least replace the impeller every two years, you need to replace the oil in that cavity, it lubricates the cam and pump arm. Fill it with engine oil 25W40.
Posted: Thu Mar 08, 2012 12:36 am
by jddens
OK, not to change the subject but I'm confused...what's the oil for???...the fuel pump? fresh water pump?...........John
Posted: Thu Mar 08, 2012 8:14 pm
by Big D
The fuel pump is bolted on to and is run by the raw water pump which is turned by a belt. The oil is in the cavity to lubricate the cam and fuel pump arm. Since the pump is no longer bolted to the block, they had to come up with a way to lubricate the drive mechanism as it would be in the block. When GM stopped running mechanical pumps re EFI, they didn't punch a spot anymore in the block to mount a mechanical fuel pump. This was Merc's quick fix to be able to continue running a mechanical pump.