Leaking Air Actuated Drain System

[M298SS-VA]

This is the exact same problem I am experiencing, does anyone know if there is a piston, 3 o-ring and seal kit replacement for part #8 or only the whole rear unit?
My engine info is 2005 Mercruiser T350MAGMPIHOBR3 Twin-300 Serial No: OW312011 / OW312006.
I have been looking all over and this is the first "air actuated" reference I have found and it seems perfect for my issue, just a little costly for the possibility of two #863674A05.

 

[GA_Boater]

Moved from here - http://forums.iboats.com/forum/engi...s-outdrives/489729-air-actuated-drain-systems. which is a 4 year old thread. Look at the Help Tips on top of the page. Thanks.

 

[M298SS-VA]

Sorry about the post to a really old post. Thanks for creating this new thread.

Recap from pre-post:
My two air actuated seawater pumps are leaking from the air actuator cylinder (just behind the #10 blue plug in attached drawing).

Trying to find out if there is an O-ring kit (piston, 3 O-rings and seal) for #8 vs the entire back half of seawater pump (where to find OEM choices for 863674A05?)

 

[Fun Times]

Both engines are leaking? Do you typically use the air drain system for winter by using the air pump on top of the engine?

Try pumping the system up and releasing the air a few times to see if it will release itself internally. Also try giving them a light smack with something to see if their just stuck in the open position.

Mercruiser doesn't offer a repair kit for that. You'd have to pull it apart and see what you can do with it. Maybe match O-ring sizes with new ones. At the very least from pulling it apart first, you'll have to buy new ones which you're already investigating.

Should you want to do away with that part of the air system, save some money and drain it by hand via the blue drain plugs, you could order and install the non-air fitting cover 862776A01 item number 9, http://www.mercruiserparts.com/Show...=11681&bnbr=320&bdesc=Sea+Water+Pump+Assembly

Using the part number/s, keep an eye on eBay for lower prices.

And welcome to iboats!

 

[M298SS-VA]

Yes and Yes.
Sounds like some excellent troubleshooting ideas, will try this tomorrow during high tide.
I have my fingers crossed for them to be stuck open.
Thanks also, for the alternate replacement option and where to look for them.

 

[M298SS-VA]

I tried the troubleshooting ideas with no success. I ordered two "item #9, Impeller Housings w/o Air".
My only concern is, if the hoses are going to be an inch short of connecting to the new shorter "item #9, Impeller Housings w/o Air".
Hopefully there will be enough slack in the hoses, find out this weekend.

 

[M298SS-VA]

I tried swapping these out last weekend, with no luck, is there a secret to getting the top red reinforced hose off?
Guess I will search the forums some more.
Also, the rear seawater pump w/o air is composite and the rear with air is brass. Mercury said that connecting the rear composite to front brass is OK.

 

[alldodge]

I tried swapping these out last weekend, with no luck, is there a secret to getting the top red reinforced hose off?
Guess I will search the forums some more.

Not any tricks, loosen the clamp fully, then try to twist it until in will turn even a little. Once it will turn it is no longer stuck or glued. Then comes mussel and determination. If you can get something between the hose and the housing (flat screw driver) or use a hose pick but be careful with the composite housing.

Also, the rear seawater pump w/o air is composite and the rear with air is brass. Mercury said that connecting the rear composite to front brass is OK.

No issue with composite housings, just need a bit more care when working with them. They also take a bit less torque when you put the bolts back in

 

[M298SS-VA]

Well the sad news for me is that the Composite (Non-Air) rears are two to three inches shorter than the Brass (Air) rears, meaning the distance needed to be able to mount the pump where it goes is too short. I broke down and bought the Brass (Air) rears, they should be in by end-of-day Thursday and hopefully on this weekend and I will hopefully be without a leaking boat.