alpha one impeller installation question

[yamahadude9]

Hello im doing an impeller on my 1987 alpha one, im almost done but im stumped. On the top of the water pump housing there is a void between the metal liner and the plastic casing. Is there supposed to be a rubber ring in there or does it go on top outside the case ? Something must seal the top of the water pump ?? my pump kit came with a rubber ring but its one of those stupid universal kits so ill have some left over parts. 3 large o ring, 2 gaskets,2 plastic washers to be exact and the rubber ring . I got this kit

http://www.amazon.com/gp/product/B004S6L99I

This picture below indicates the rubber ring, the only thing is my water pump housing isnt flat on the top like shown in the pic

 

[greg82255]

Re: alpha one impeller installation question

You definitely need that ring, and it's supposed to be flat, not rounded, and it slides on the shaft on top of the housing. Install the impeller, then the housing, then the ring. If you don't have it in your kit I'd go to your local merc dealer and they will have it. go to www.mercruiserparts.com and find your engine to locate the correct part #. Best of luck

 

[Don S]

Re: alpha one impeller installation question

It doesn't "Seal" anything. It's called a centrifugal slinger.
Just push it down against the top of the pump housing. Nothing fancy, just up against it. That's all it takes.
If you look at the cross section, it's about 1/4" square.

 

[ziggy]

Re: alpha one impeller installation question

yep, it supposed to have a centrifugal slinger that slides down the drive shaft and sits on top of the water pump housing.

this is the centrifugal slinger..

thats the top of the water pump where the slinger sits.

and that's how it sits when assembled. the slinger just sits on top of the water pump housing.

the slinger comes with the oem water pump kit. don't know if it comes with what you purchased or not.

 

[yamahadude9]

Re: alpha one impeller installation question

cant thank you guys enough, i think i found out why the slinger wasnt there when i disassembled it. This thing got very very hot, i feel like an idiot now, i just spent a bunch of money putting new floors,carpets, seats, interior in and and i bet this whole drivetrain is junk !! The tube that bolts up above the waterpump with the 4 bolts that holds it on is so melted its not recognizeable. Its encased the bolts in plastic which i was able to chip of to get at the bolts and get them out. Dont know what to do now though, im thinking every piece of rubber/plastic in the cooling system must be melted !!

 

[yamahadude9]

Re: alpha one impeller installation question

 

[dubs283]

Re: alpha one impeller installation question

thats nothing

ive seen em MUCH worse than that, where the whole pump assy is melted!! and the tube(s) are unrecognizable, and the engine still runs!!

if you are very concerned, do a compression test on the engine to ensure you don't have a gasket failure, etc...

check out all the wiring on the engine too, make sure nothing is melted, check bellows, exhaust boots, etc...

 

[yamahadude9]

Re: alpha one impeller installation question

Thought i just wasted 2g's fixing up a turd when i saw that. Thats a major relief to hear, im definitely doing a compression check and leak down test on it now and ill go through all the wiring too. I already cleaned out the heat exchanger put new gaskets and end caps on that. I also replaced every coolant hose on it and the bellows is good. Just concerned about a head gasket now because this is a mercruiser 470 and they are notorious !! But ive run it on muffs a few times and it ran excellent, no overheating, no coolant in the oil. Is there any other plastic or rubber upstream from that i should look at too ?