Water In Lower Unit?

Blu_Lunch

Blu_Lunch

Junior Member
I got home from work today and I noticed a bit of gear lube had run down from the top screw fill on the lower unit. So I drained the lower unit and it was tilted up so I cracked open the bottom screw and held the drain pan under the lower unit as my son tilted the engine down so I would not spill any fluid on the new driveway..... first thing we got was about 3 oz of crystal clear water then what appeared to be normal loking fluid not the milky mess like when my Johnson had a bad seal in it. I had run it on the muffs Saturday after installing and new water separter filter to check for leaks. What I did noticed that the seal on both screws were shot....What do you think? The only thing I can think of is that water was in the prop but what about the fluid leak from the screw? 1983 150 HP Black Max
 
If were me I would replace the screw O rings, add all new oil, run the motor shift in in and out of gear.

Shut off let sit for 1 hour and then drain the oil and see if you get any water??

if no water then I would go ahead and refill with yet more new oil and you will be all set!!

Then the next time out on the water, when you get home, drain yet again to insure that no water got it again from some were else.

If clean you all set!!

If water then take to have the thing persure tested to see were the leak is?? Replace all seals needed to do the job right.

Good Luck!!
 
I like to replace those screw gaskets every year. It's cheap insurance. How long since the last time you ran the boat? If it's been sitting, the oil and water should separate. The water will be at the bottom of the lower unit because of the higher density than oil. Gas and oil float on water right? Therefore the water exited before the oil.
If it were mine, I'd replace those gaskets, make sure you didn't wrap any fishing line or anything else behind the prop. Fill her with fresh oil and run it. Then check it after the next use.
Good luck Blu.
 
I bet the gaskets on the screws were bad, the top one was leaking fluid that's how I noticed it. I poured the fluid in to a clear soda bottle and it separted in less than 10 minutes only about a oz was in the fluid. The boat was out on Long Island Sound all day Friday and I ran it on the muffs friday to flush it and Saturday when I changed the water serpartor and there was no leak from the vent that I saw then..... I'm going to put new seals tommorrow and see what happens..
 
Blu I had water in mine and it was from no gasket being used in the top screw hole and and old one in the bottom. Done by the marina Fillet used. Changed it and checked after the next day of fishing and dry as a oil should be.
 
HI,BLU:

FIRST, DO NOT ADD ANY ADDITIVES IN YOU LOWER UNIT OIL, IT NORMALLY CONTAINS MOLLIBDENUM WHICH IS A VERYYYY GOOD LUBRICANT. REPLACE THE SCREWS GASKET AND REMOVE YOUR PROP TO SEE IF YOU HAVE CAUGHT ANY LINE. START THE ENGINE WITHOUT A PROP
AND RUN IT FOR FIVE MINUTES (FULL OF OIL, OF COURSE) TO SEE IF THERE IS ANY LEAKS.

THE BEST THING IS TO DO A PRESSURE CHECK (15 LBS OF AIR).

ANYWAYS, THE NEXT TIME YOU GO OUT BE CAREFULL AND WATCH IT.

IF YOU NEED SEAL KITS LET ME KNOW, I'M A MERCRUISER EXPORT DISTRIBUITOR.

LESTERUS
 
Skools,

I just ordered Seal Lube. How much do you use in the LU during a oil change?? Do you pre-mix it into the LU oil??
 
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