Volvo TAMD41P raw water pump

alancollins

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Having had all the innards of my raw water pump renewed, my engine overheated when I next used it. Sea Start towed me home after spending an hour trying to find the problem, without success. On the way back to my berth the engineer wondered if the pump could have been installed upside down. I have looked at a parts diagram of the pump, but it looks the same both ways up. Apart from the name Volvo there is nothing marked on the pump, no arrows to show the direction of water flow, so I am as puzzled as the Sea Start chap. Any ideas anyone?
 
Its entirely possible, if you work out which direction it rotates then the shoe in the pump that compresses the impellor blades should be on the side where the blades are travelling down from 12 o'clock to 6 o'clock, if this makes sense.
If it was installed incorrectly and you had 'reversed' operation, then examine the rubber joint on the exhaust to check it didn't get fried by lack of water in the exhaust.
The pump housing should cool down noticeably after starting the engine and the exhaust bend should be cool at idle which indicates seawater is going through the entire system.
 
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It might surprise someone:
PumpOperation.jpg
 
I have experienced an air lock with these pumps a few times, often had to prime if the boat been out of water of drained for winter, easiest way to see if its wrong way round is look at the above drawing and look at yours to see which side the cam screw is on.
 
I have experienced an air lock with these pumps a few times, often had to prime if the boat been out of water of drained for winter, easiest way to see if its wrong way round is look at the above drawing and look at yours to see which side the cam screw is on.

Thanks gentlemen. Very helpful. I will take the pump off tomorrow and see whether it's fitted the right way.
 
you do not need to remove the pump just the cover

You don't need to remove pump or the cover, just look which side the cam screw is and that will tell you all you need to know, should be on left side when looking at front of engine.
 
Volvo TAMD41 raw water pump

You don't need to remove pump or the cover, just look which side the cam screw is and that will tell you all you need to know, should be on left side when looking at front of engine.

In fact I removed the pump as I couldn't see or feel a cam screw and replaced it the other way up. With nothing external to indicate the direction of water flow it seems that the pump needs to be installed with the Volvo Penta logo upside down! All systems go. Thanks everyone.
 
The 41 p has the cast type pump with no separate cam plate , it's machined into the pump casting .

The plate is on upside down , not a problem though .
 
The 41 p has the cast type pump with no separate cam plate , it's machined into the pump casting .

The plate is on upside down , not a problem though .

The one I looked at must have an aftermarket pump or one from earlier engine as it has a screw, most pumps of that age would probably have been worked on by now.
 
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