# Upper water tube seal merc 9.9



## Timoto (Feb 7, 2018)

So I was doing a water pump kit on my 1995 merc 9.9 and had no flow when I was done. I dropped the lower unit again to see what was going on and the upper water tub fell out.

I cant seem to comprehend how this tube stays in place. There is a seal on the tube but the top of the tube is flared and the seal is under the flare on the tube, so it can freely move up and down.

Looking at the parts diagram the seal is above the tube flare and not on it. Is it possible the tube got pushed up and forced the seal down? As of right now if I push the tub in place it just falls right out if I bump it.

Can the upper water tube be installed without removing the upper unit? I'll snap a pic when I got drop the lover unit here in a bit

Thanks for any help

https://imgur.com/a/JQMP5IC <---- parts diagram #17


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## Finsleft258 (Oct 7, 2018)

Yes, this can be done. On the Merc/Tohasu engines (what you have) there is a simple grommet in the powerhead that holds the tube in. I recommend putting some RTV silicone on the outside of the tube to help hold it in place when you reinsert it. It is a total bitch to do btw. You basically just keep using braille until you find the hole (I'm sure there's a joke for that somewhere).


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## Finsleft258 (Oct 7, 2018)

https://www.boats.net/catalog/tohatsu/2002/m9-9c-2-stroke-tohatsu/driveshaft-housing-gear-case

Notice how the tube slides up behind the exhaust. It's slightly offset to the right if I remember correctly.


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## Timoto (Feb 7, 2018)

Hi thanks for the reply. I'm just trying to make sure I understand this properly. The seal does go on the tube under the flare but I should glue it in place first?

This kinda makes sense since the old seal seemed to be frozen in place under the flair and I hade to cut part of it off.


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## Timoto (Feb 7, 2018)

Finsleft258 said:


> Yes, this can be done. On the Merc/Tohasu engines (what you have) there is a simple grommet in the powerhead that holds the tube in. I recommend putting some RTV silicone on the outside of the tube to help hold it in place when you reinsert it. It is a total bitch to do btw. You basically just keep using braille until you find the hole (I'm sure there's a joke for that somewhere).


So this is what I have now. I glued the seal to the tube with some rtv. I stuck it in then hole and blew through the T-stat hole and i can't blow through if I block the bottom of the tube with my finger. Not sure if correct but seems like it will work and yes it's a MF to put in the hole!


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## Finsleft258 (Oct 7, 2018)

You got it then


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## Timoto (Feb 7, 2018)

Finsleft258 said:


> You got it then


tyvm for the guidance. Shes pumping water again!


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## Timoto (Feb 7, 2018)

Finsleft258 said:


> You got it then


Got one more question. I seem to have a exhaust leak at the lower unit where the water pickup tube seal it. I had this leak before I tore it down the first time and it's still the same. The rubber bushing is in correctly with the little nub on the bushing in the hole like it should to block it be but exhaust seems to be exiting from there as well. 

Other than that it seems to be pumping water good, water temp is warm but thermostat open warm like 120 seems to be ok to me. took her for a few hot laps and didn't blow up.

Should I be concerned about bubbles coming from here when it's idling?


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## Finsleft258 (Oct 7, 2018)

Timoto said:


> Got one more question. I seem to have a exhaust leak at the lower unit where the water pickup tube seal it. I had this leak before I tore it down the first time and it's still the same. The rubber bushing is in correctly with the little nub on the bushing in the hole like it should to block it be but exhaust seems to be exiting from there as well.
> 
> Other than that it seems to be pumping water good, water temp is warm but thermostat open warm like 120 seems to be ok to me. took her for a few hot laps and didn't blow up.
> 
> Should I be concerned about bubbles coming from here when it's idling?


No. It's a relief for the lower unit water passages. The bubbling is incidental mixing from the exhaust.


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