Alpha 1 gen 2 water pump rebuild part differences

MarkSee

Lieutenant Junior Grade
Joined
Sep 10, 2010
Messages
1,172
First, I'd like to thank everyone for their contributions to these forums as this is a great learning place and confidence builder to tackle some projects knowning the information and help is available. I have been reading for serveral months and now asking my first question.
I'm doing the annual servicing on my 2005 alpha 1, gen 2 s/n 0w068186 and have the drive off and halves separated with new oem parts obtained. I ordered the complete water pump rebuild kit (817275Q05) and noticed that the gasket/wear plate/gasket trio is now a one piece item that I have found to be part # 86623301. It has a rubber bottom and the install instructions does not mention about using perfect seal between the housing and this rubber like what was done when the old style 3 piece setup was used so would you think go by the instructions and not use perfect seal or use some anyway? This rebuild kit also has another different part than what I've seen and that is the seal that goes over the shaft on top of the water pump housing; the seal in the rebuild kit I researched to be part #26-861415. I also ordered as a spare the same seal and tool kit which is part #26-816575A 2 but I immediately noticed that while the top half of the two seals are the same, the bottom half of the seal in the seal/tool kit is larger meaning more surface area will be in contact with the pump housing; the seal in the seal/tool kit is also slightly taller in size overall than the one in the full water pump kit. The seal that I removed the previous owner had installed was the smaller seal. Maybe this is just a change in parts Mercury is doing but does anyone have any opinion on whether to use the smaller seal from the full rebuild kit or use the slightly larger seal from the seal/tool package?
Thanks for the feedback.
Mark
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Alpha 1 gen 2 water pump rebuild part differences

Welcome to iBoats....

26-861415 supersedes to 26-816575A 2, so use that one and discard the first. I have never used any sealant on water pump gaskets, it makes it just too hard to get them off again next time. Just be aware that you need to use the alignment pins when re-assembling the water pump housing. It can cause problems if you don't...

Chris........
 

MarkSee

Lieutenant Junior Grade
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Sep 10, 2010
Messages
1,172
Re: Alpha 1 gen 2 water pump rebuild part differences

Yep, I do have the alignment pins. Also bought the little orange tool for the shift slide to support it when I put the drive back on.
thanks for the info.
Mark
 

bobhol

Petty Officer 2nd Class
Joined
Oct 5, 2009
Messages
146
Re: Alpha 1 gen 2 water pump rebuild part differences

Just curious...why are the pins so important ...I didnt use them when I changed my impeller ...no problems but was I just lucky?.:confused:..regards,Bob
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Alpha 1 gen 2 water pump rebuild part differences

The pins do help keeping the gaskets and plate aligned while you turn the shaft and push the housing down. I just cut the heads off a couple metric bolts and instant pins.

As far as the sealant goes, I never used it either, unless the housing had a lot of corrosion on it. For the same reason Chris mentioned. To hard to clean. Or you have an overheat above 3000 rpm. Here is the service bulletin that explains that.
 

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MarkSee

Lieutenant Junior Grade
Joined
Sep 10, 2010
Messages
1,172
Re: Alpha 1 gen 2 water pump rebuild part differences

The reason I was asking about using perfect seal is that I found this excert from service manual 14 and on page 3b-75 (7) it mentions about using perfect seal and if that might still be applicable using the new 1 piece gasket. I'm not sure if the service bulletin with number 95-13 preceeded this 2001 manual or if this is an outdated step being from a 2001 manual and only need to use the sealant if it runs hot.
Mark
 
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