496 (8.1L) Raw Sea Water Pump Replacement

[SamIAm]

Hello all,
I have a 2007 252 with a 496 Mag (non HO). I recently noticed a squeak coming from the motor compartment. I opened the motor hatch and narrowed it down to the sea water pump pulley (bottom starboard side of motor). I then noticed water dripping from behind the pulley, so I assume the sea water pump front bearing is shot (noise plus water). The motor is not overheating (yet). I have read several threads on rebuilding the sea water pump...but nothing on the best way to remove the pump from the motor? It looks very difficult to get to? I have the 'air pressure' water drain lines hooked to the pump as well. Is it possible the remove the front half of the pump and leave the water and air lines connected to the back half of the pump, then install a new front half? Anyone have any tips on the pump removal process?

TIA
Sam

[DEcosse]

Hello Sam - I have a 496 (06 232) and I replaced the complete pump on mine. I'm not sure about the air pressure lines, however mine didn't have that.
But otherwise it's pretty straight forward to remove the whole thing.
(You have to remove the whole thing anyway, splitting it will not help you with the replacement parts which will be on the back - front half is only the housing that moves the water)
You have to remove that 'stay' (item 3) that supports it, but it's only 2 bolts (item 4) onto the engine and three bolts (item 2) holding the pump assembly. If I recall correctly you have to align the holes in the fan to the bolts and those are socket cap (allen) heads I believe. So you need to put your hex wrench through the fan hole to the bolt head. Of course you need to first need to remove the serpentine belt and remove hoses 5 & 6 from the pump by loosening clamps 7 & 8

seawater pump.png

If you have a picture, or the exact model of your engine, I can probably find the schematic for it and see what might required regarding the air hoses.
It should have a label right on the top of the motor with the model type e.g. MIne is an 8.1 OSI-C

Also, find my thread on engine clicking noise - I had a problem that turned out to be my throttle body.
(Not saying this is what your problem is, just a point of reference for future)

[SamIAm]

Thanks DE for the reply.

It looks like you have a Gen 5/6 pump and mine is a Gen 7 with air-lines (see picture). I think I can get to 5 of the 6 bolts holding the front and back half together. Two of the bolts hold the pump to the bracket, so I may be able to get to the 6th bolt once the pump is apart from the bracket? It would be very difficult to get to the water hose clamps and I can't even see the air-lines. I'm hoping to just replace the front half assuming minimal wear on the back plate. If the wear is bad on the back plate, I may go with a Hardin pump that comes with a separate backplate. The jury is still out on if I can get this thing out? I will attempt later this week. Still looking for suggestions and tips on removing a Gen 7 and if I can just replace the front half? I know they sell the front half separately.

[DEcosse]

facepalm! I'm sorry - I need to read better - you have a Mag, I have a Volvo

[Titaniumboy]

Maybe this will be of use?

http://www.clubsearay.com/index.php?th ... res.26440/

[SamIAm]

Thank You for the link Titan,
The pump on the link is similar (Gen 7 with no air lines). Motor pulley set-up is different than mine. Mine has a spring loaded tension pulley that I can rotate clockwise with a 1/2" socket to loosen the belt. On the link, he can remove 2 pulleys with one bracket. I don't think mine is set-up like that. I wish I had that much room to remove the pump! The link was helpful regarding hose and sensor removal. Thanks again!

[SamIAm]

Follow-up:
This is for information only, your experience may vary. I was able to remove the raw water pump by gaining access to the lower front of the motor by going through the storage compartment on the Port side of the boat (2007 Cobalt 252). This seems counterintuitive since the pump is located on the lower starboard side of the motor...but the port storage has access to the front of the motor and I was able to reach the (2) 10mm bolts that holds the pump to the bracket. I used a 10mm wrench with a ratcheting end. My regular socket wrench would not fit in the space. There is also a 10mm bolt just behind the top of the pulley (totaling 3 bolts holding the pump to the bracket). To clarify, I did not remove the bracket from the motor...I removed the pump from the bracket.
My model has airlines you can pressurize to drain water, so I loosened these air lines at the 'top of the motor' so I could lower the pump to gain access the other 10mm bolts holding the two halves of the pump together. This allowed me to remove the front half of the raw water pump (the back half was in good condition so I did not remove it). I ordered a new pump (with pulley installed) from eBay. I reversed the process to install the new pump.

[AsLan7]

Appreciate the follow up SIA.

[Titaniumboy]

Nice job SamIAm ! Any pics of the ordeal?