Water Circulating Pump

[MC1600]

Everything is fine with the engine (finally!?), but I have noticed my water circulating pump weeping a little. Note this is NOT the raw water pump, but the circulating pump in the middle of the engine.

I would rate myself a 6 or 7 out of 10 in mechanical ability (I could replace a transmission, but not rebuild it). Is this a DIY project for me??

Thanks guys! This forum is INVALUABLE!!!!

Matt

 

[Pirate]

If you're a 6/7 out of 10 mechanically, a water pump on a GM 350 shouldn't present a problem. A shop manual would probably provide the confidence you're looking for.

 

[MC1600]

Thanks Matt! Is SELOC going to be the best??

 

[fwebster]

If you do this yourself, be sure to check all the parts and components behind the water pump. Mercruiser paints the engines after they are assembled and the timing covers, etc. are not painted. They always rust so look for pitted metal and replace the timing cover if you find yours getting thin......and paint the new one before putting the water pump on.

 

[Dave S]

Matt

That's an easy DIY fix if indeed it is leaking. But I would still have your dealer push to see if they can get Mercruiser to replace it under warranty even if your boat is out of the warranty period because some times they will make exceptions especially if you have a low hours motor.

Frank also mentioned painting the timing cover. It's not necessary to worry about that anymore on the newer 350 MAG engines. Mercury (or GM who supplies these engines) went to a composite timing cover several years ago. The composite cover will never rust. But if the timing cover ever needs to be removed, Mercury also recommends you do not re-use it. My engine oil leak that was fixed several weeks ago required the removal of the timing cover and they had to install a new one.

Dave

 

[MC1600]

Good suggestion, thanks, Dave! I know the warranty just expired a month ago, so maybe they will show some mercy on me! If not, and I end-up doing it myself, I will make sure I just replace the timing cover too.

 

[Dave S]

Good suggestion, thanks, Dave! I know the warranty just expired a month ago, so maybe they will show some mercy on me! If not, and I end-up doing it myself, I will make sure I just replace the timing cover too.

Matt

You don't need to touch the timing cover to to replace the water pump. The pump strattles the timing cover and you just remove the bolts on the ends of the water pump itself. You will need new gaskets for the pump and of course a new pump but it's strictly a bolt on job. Here is a picture that may help you out. (In this picture my timing cover is off because of my oil leak but you can see the two water passages on either side of the timing chain.)

The pump bolts on with two bolts on either side. It is as simple as that. The only other thing you will have to do is unbolt the pulley on the old pump and put it on the new one and reconnect your hoses.

I only mentioned the timimg cover in my first reply so you know it does not to be painted due to rust out since it's plastic composite and not subject to rust. There are very few instances where the timing cover has to come off an engine. My recent oil leak was one of them.

Dave

 

[MC1600]

Got it! And thanks for clarifying on the timing cover. That picture is worth 1000 words. Thanks Dave!

 

[Dave S]

Here is what the pump looks like Matt

http://www.sterndrive.info/sterndriveparts/engine_water_pumps.html

 

[MC1600]

Alright, the more I see of the insides, the less concerned I am. This looks pretty simple.

I'm just gonna wait until next week to do it. We've got family coming this weekend, and now that we've got the water pressure/smartcraft/alternator issue taken care of she's running great [knock on wood], so I'm not going to touch a thing to disrupt our date with good luck [again - knock on wood].

 

[Dave S]

If your engine is raw water cooled, be carefull if you are going to change the pump with the boat in the water. I am not sure if that part of the engine is below the water level or not. If it is, water will start pouring in so look at the water level carefully before you start removing anything just to be sure you are OK and you don't sink the boat. :wow:

On the other hand, if you have a closed cooling system you don't need to worry about that. But you will need to drain your antifreeze before pulling the pump.

 

[MC1600]

...so look at the water level carefully before you start removing anything just to be sure you are OK and you don't sink the boat. :wow:

Now THAT'S good advice!! :thumbsup:

It IS raw water cooled, so I will double check that before I proceed. Since this doesn't look like it will take more than a few minutes once I get everything set, maybe I'll just have my dockmaster slip it on the forklift long enough for me to do the swapout.