Alpha I Gen II Raw Water Pump Troubles

[jakebird]

Can anyone help here? 2004 Merc 5.7L with 2007 Remanufactured Lower drive. When I hook a clear hose between the power steering cooler and the thermostat housing, large air bubbles are being pumped to the engine over 3000 RPM. Pump housing is torqued to 60 inlb, I used RTV Ultra Black on the pump plate, the pump plate is the "new design, with a rubber gasket fused to both sides of it. The way I see it, there is only 2 places that the pump could suck air. From the top of the cover were the shaft goes through, or from under neath the cover were the plate is. Any help is much appreciated.

 

[jakebird]

Re: Alpha I Gen II Raw Water Pump Troubles

Bump? Anyone have any input?

 

[tommays]

Re: Alpha I Gen II Raw Water Pump Troubles

You have the rubber dam between the exaust and water pump if it leaks it could force exaust gas into the pump

And then the slinger ring on top of the pump is about the only other place except the gaskets as i have not seen the new plate


Tommays

 

[jakebird]

Re: Alpha I Gen II Raw Water Pump Troubles

Thanks for replying. The rubber dam is in place. There is also a plastic plate that slides into the upper housing and sits ontop of the rubber dam. How would the rubber dam leak? it is new, and looks in good shape with a tight fit. Is there supposed to be sealant on or around it?

 

[milkyway]

Re: Alpha I Gen II Raw Water Pump Troubles

Stupid question - was the outdrive on muffs or submerged when you noticed this?

 

[Don S]

Re: Alpha I Gen II Raw Water Pump Troubles

Stupid question - was the outdrive on muffs or submerged when you noticed this?

That's the exact question I was about to ask.
If you had it on muffs, you WILL have air bubbles. No way around it.

 

[jakebird]

Re: Alpha I Gen II Raw Water Pump Troubles

The boat is in the water when I test it.

1) Can anyone tell me if there is supposed to be sealant on top and around the rubber dam?

 

[Don S]

Re: Alpha I Gen II Raw Water Pump Troubles

http://www.boatfix.com/merc/Servmanl/14/14b3.pdf
Go to page 3B-78 for when to seal the dam.

You might also want to check the gasket between the SS base plate for the pump and the housing. That gasket is designed to only go one way, but can be put on upside down and may not seal on one edge.

 

[jakebird]

Re: Alpha I Gen II Raw Water Pump Troubles

Thanks Don S.

My new remanufactured lower drive came complete with the ss base plate that is encased in a rubber gasket. I talked to the Merc engineers, and they said that this "new" base plate does not require the paper gaskets like the old ones did.

I have that manual. It calls for Permatex when using the Aluminum dam. I also have manual 90-806534960. If you look at the exploded parts pages, it calls for Permatex Blue on one page, but does not on the previous page.

I have been scouring the manuals to try to figure this out. I have found numerous errors in the Merc manuals.

Does anyone know if the permatex is required?

 

[tommays]

Re: Alpha I Gen II Raw Water Pump Troubles

Are you saying they are not using gasket 23 and 24 ?


tommays

 

[Don S]

Re: Alpha I Gen II Raw Water Pump Troubles

I have found numerous errors in the Merc manuals.

Such as????????

the pump plate is the "new design, with a rubber gasket fused to both sides of it. The way I see it, there is only 2 places that the pump could suck air.

I haven't been working on boats for about 2 months now, but even when I left there was nothing about anything like that. Even for the 2007 outdrives, the Merc site is still showing the use of the regular plate and 2 gaskets.
I have to wonder if you have something aftermarket and possibly NOT OEM Mercruiser.

 

[jakebird]

Re: Alpha I Gen II Raw Water Pump Troubles

Tommays, Yes, they are not using those gaskets. This is a Remanufactured Lower Drive direct from Merc. The pump base Plate is encased with a rubber gasket. I talked to the Merc Engineers, and they said that this is the latest design.

Don S. Here are some of the errors:

Mercs part list on their website gives a part # for a Turbulator Gasket for the dry joint risers, but the gasket that it calls out is not a Turbulator Gasket.

Got to the next page of the manual that Tommays listed, look at part # 38. Then look at the description of it. They call this a screw??? I have found many other errors. I don't want to get side tracked on a different subject....

Back to some of my questions. Can anyone tell me if the Permatex is required on and around the dam? Look at the page that Tommays posted, then look at the next page of the manual that gives the exploded view of the Drive Shaft Components. It calls for the Permatex, but the previous page does not. then Look at the Manual page 3B-78 instructions that Don S. posted. I Says to use the Permatex when replacing the Aluminum dam. Which one is correct??

 

[tommays]

Re: Alpha I Gen II Raw Water Pump Troubles

The manual covers all GEN II drives from 1991 so it also covers the changes up to the point it was printed

It is also made for someone who has gone to merc schools (not that i am a merc expert ) and not a teaching book


The orginal dam was ALU and required a sealer the NEW dam is rubber and it can not hurt but should not require sealer



Tommays

 

[BigSteve1967]

Re: Alpha I Gen II Raw Water Pump Troubles

would anyone have the link for outdrives Pre 1991?