Circulating Pump on a Mercruiser 3.0

boateecat

Cadet
Joined
Jun 11, 2012
Messages
10
Hey All,

This is my first post to this forum, although I have researched topics and have been able to learn quite a bit from posts to solve most of my boat problems. Thanks to everyone for the help.

Here is my issue:
I have a Mercruiser 3.0 I/O, Alpha One Gen II, sn L346717 with what appears to be a leaking circulating pump. When I go to mercruiserparts web site and type in the sn, up pops a diagram that does NOT look like my application.:confused: Some of the other diagrams show the correct configuration of what the front of my engine looks like, but it does not match my sn. One diagram shows a cover assembly with a seal and gasket, which is the style I have. But those parts are not shown on what is 'supposed' to be the correct diagram for my serial number. Regardless, the circ. pump part number is the same.

My problem is that the service manual (#26) in this forum does not show instructions for removing and replacing this pump...at least nothing that I could find.

My questions are:
1. Can anyone provide instructions or point me in the right direction where I might find info for replacement of this pump?
2. How difficult is this procedure? (l've replaced water pumps on autos previously)
3. Are there any special tools or other special items I need to be aware of.
4. Are there other parts that should be replaced WIIT (while I'm in there) other than the belt?

I appreciate any help you can offer. I am relative newbie to boats...bought m7 first one (1999 Bayliner Capri 1952 Cuddy) last year and I enjoy it tremendously.
 

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,092
Re: Circulating Pump on a Mercruiser 3.0

remove large water hose,loosen the 4 bolts on the pully, remove belt, remove 4 bolts and remove pully,remove 4 bolts that hold pump to block and clean surfaces.
install new pump and gasket, assemble in reverse order.
install a additional belt at this time and safely tie out of harms way.save thge trouble of removing the spacer block
 

boateecat

Cadet
Joined
Jun 11, 2012
Messages
10
Re: Circulating Pump on a Mercruiser 3.0

So...what about this cover assembly (#7) and seal(#9) shown on the diagram attached? Does that have to come off too? Should I replace the seal? Will I need a pulley puller? New belt for water pump? I read about zip tying a new one for the alternator, but one for water pump too? Or is it one and the same?
 

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Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,464
Re: Circulating Pump on a Mercruiser 3.0

So...what about this cover assembly (#7) and seal(#9) shown on the diagram attached? Does that have to come off too? Should I replace the seal? Will I need a pulley puller? New belt for water pump? I read about zip tying a new one for the alternator, but one for water pump too? Or is it one and the same?

Ayuh,... #7 is the timing cover, 'n #9 is it's gasket, you ain't touchin' either of 'em, nor the seal...

The 3.0l only uses 1 belt, unless it's P/S equipped...
 

boateecat

Cadet
Joined
Jun 11, 2012
Messages
10
Re: Circulating Pump on a Mercruiser 3.0

Thanks Bond-o. It appears that the circ pump is behind the cover. Will I be able to remove the pump without removing the cover? I guess I'm gonna go to the lake and look at this closely and take some pics and begin the disassembly.
 

boateecat

Cadet
Joined
Jun 11, 2012
Messages
10
Re: Circulating Pump on a Mercruiser 3.0

OK...just got back from lake. I see now that the Timing cover assembly is lower than the circ pump. The diagram would be much easier to read with some dashed lines showing where the bolts connect, but I guess those diagrams were originally meant for mechanics... not the DIY'er. I routinely do CAD drawings and would have put them there if it were my drawing. Oh well.

Not alot of room in the doghouse, but I should be able to access w/o issues. Gonna order a new belt and install, while using the existing belt as the emergency back up belt. It still looks to be in good condition. Thanks for the tips everyone:) Might prevent me from getting stranded on a big lake like Ontario someday.
 
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