Water Drip Behind Engine on 99 Sundance 260 with fresh water cooled 7.4L/Bravo III

jgyatesjr

Member
Oct 27, 2008
51
Live in Waterford, VA and boat in Potomac River
Boat Info
1999 Sundancer 260
Engines
Mercruisre MX 6.2 MPI with Bravo III (repowered from 7.4)
Water Drip Behind Engine on 99 Sundance 260 with sea water cooled 7.4L/Bravo III

I have water dripping behind the engine on my 1999 Sundancer 260. The 7.4L engine is sea water cooled (that is sea water circulates through the engine). With engine off, the drip stops after a while. I assume it stops because the leak is from engine (freeze plug?) or exhaust system (Y-pipe). If it was from outsdie it would leak continuously, right?

Can't see where the drip is coming from. I plan to get snake camera to see better especially with engine running.

Any other ideas?

Thanks
John
 
Last edited:
Re: Water Drip Behind Engine on 99 Sundance 260 with fresh water cooled 7.4L/Bravo II

y pipe would leak all the time,running or not.Core plugs are brass and shouldnt corrode.
most likely the rubber exaust couplings
 
Re: Water Drip Behind Engine on 99 Sundance 260 with sea water cooled 7.4L/Bravo III

The transom assembly leaks when underway at the gooseneck fitting. Will stop when you stop
 
Re: Water Drip Behind Engine on 99 Sundance 260 with sea water cooled 7.4L/Bravo III

Check the water line going to the oil cooler it's mounted in the rear and will only leak when running, I had this happen a couple years ago just a loose hose clamp, maybe you'll be lucky.
 
Re: Water Drip Behind Engine on 99 Sundance 260 with sea water cooled 7.4L/Bravo III

I just found some videos of the rear of the 7.4 on YouTube and checked diagrams of the water system and yes a leaking oil cooler is a possible candidate. Thanks for pointing me in this direction. I have ordered a snake video camera and will inspect from the inspection hole at rear of engine hatch. I think this will work. I am not familiar with transom gooseneck. Will have to research. I will also ck exhaust couplings. Thanks!
 
Re: Water Drip Behind Engine on 99 Sundance 260 with fresh water cooled 7.4L/Bravo II

I hope its not the dreaded steering pin leak :O

Jeff
 
Re: Water Drip Behind Engine on 99 Sundance 260 with fresh water cooled 7.4L/Bravo II

I will second the oil cooler leak. The power steering cooler is mounted at the top rear and I had loose hose clamps on the water lines. Also that only leaks with the engine running.
 
Re: Water Drip Behind Engine on 99 Sundance 260 with fresh water cooled 7.4L/Bravo II

Update: Not leaking from oil cooler or sea water hose. Leak starts slowly when engine runs. Stops when not running. Leaks below drive shaft apparently from gimbal bearing/bellows. See picture. 2014-06-17 19.27.13 a.jpg.
 
Re: Water Drip Behind Engine on 99 Sundance 260 with fresh water cooled 7.4L/Bravo II

Yep, your bellows are full of water. Pull the drive and inspect!
 
Re: Water Drip Behind Engine on 99 Sundance 260 with fresh water cooled 7.4L/Bravo II

you will probaly need to replace the bearing now
 

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