Possible Trim Leak Oil Slick

[red6spd]

Hi,
1999 Merc 4.3 I/O
The past 2 seasons, I notice that I am leaving a pretty large oil slick on the surface of the water whenever I leave and enter my dock.

Over the span of the season, I lose no crankcase oil, no stern drive gear oil, but I have to add about 1 pint of trim fluid (I use power steering fluid) during the season.

So, I'm pretty sure the power trim system is the culprit, but do not know where to start checking for the leak when I take the boat out of the water for the season.
It does not leave any leaks on the ground when out of the water.

Do I just replace the trim cyliners, or are there o-rings and gaskets that I can replace as a cheaper first step? Ideally, are there good checks that I can perform to identify the actual source of the leak?

Thank you very much for any sugggestions.

 

[Haut Medoc]

Re: Possible Trim Leak Oil Slick

Welcome to iboats ....
Well, for starters, once you have it on the trailer, have someone cycle it up & down & see if you can spot it .....
Do you keep the boat moored?
If so, is it in salt water?
Losing any trim fluid is not good, 1 pint is alot....
Inspect all hoses fittings & the trim rams themselves....
There are reseal kits, what is the overall appearance with regard to corrosion?......JK

 

[red6spd]

Re: Possible Trim Leak Oil Slick

Thanks for the warm welcome!
Looks like a great forum for the DIY'er.

The boat is moored in fresh water from May through October and there is no corrosion to speak of. The stern drive is in very good shape.

That was going to be my first course of action...cycle it up and down and see if I can spot anything.

Any idea how difficult of a job installing new seals is?

Thanks,
JD

 

[Haut Medoc]

Re: Possible Trim Leak Oil Slick

http://forums.iboats.com/bbBoard.cg...://www.boatfix.com/merc/Servmanl/6/6covr3.pdf
Should be easy.....
Just make sure that is the problem....
Check out the link above, courtesy of Don S.....
Not sure why it won't link.....
Scroll down to the post by 8 ate eight....it's in there......JK

 

[red6spd]

Re: Possible Trim Leak Oil Slick

Thank you. That manual will be a great help! I have a Seloc, but this will be even more helpful.

Thanks again for your help!

 

[Don S]

Re: Possible Trim Leak Oil Slick

Just went to JK's link, and that is the wrong manual for you. You have an Alpha I Gen II
Here is the manual for the Gen II.

http://www.boatfix.com/merc/Servmanl/14/14cover.pdf

 

[rebars1]

Re: Possible Trim Leak Oil Slick

I had a similar thing happen last week...big oil slick after lowering the outdrive, not even unhooked from the trailer. I just looked over the transom and saw that one of my trim hoses was leaking. Easy to see because the oil drops float up.

Can you see a leak location while in the water?

 

[tunahuntr1]

Re: Possible Trim Leak Oil Slick

You might want to check your power steering oil cooler.They can rot internally and cause a leak to go out of the exhaust.If you find no leak in the trim system check that.I had the same problem and I was only leaking small amounts of power steering fluid.