condensation in lower unit?????

my buddy has a 1994 30 or 40hp yamaha that before the winter we changed the lower unit lube. as it was draining at the end we could see clear water coming out. the lube was very dark not milky, refilled and let sit, then put a couple more pumps for gp. new seals on plugs- that was in late sept. he took it to the shope this last wkend to have carbs checked <was running rough before storage> was told carbs needed cleaning but also that water was in lower unit???? it has not been in any water since lube change ,i used fresh lube as a flush also before pumping final lube in. questions:<br />1- could it be condensation from where its parked?<br />shady not in sun but sun barely hits it, damp swampy area of sc<br />2- could it be when they checked the carbs and run it that one of the seals is starting to go bad and sucked in some water?<br />- <br />i dont know if it was mixed in with lube or not at the shop, but when we drained it it was on top.<br />_<br />is it possible that the last water flush with hose allowed it in through a bad seal and thats why it was on top <early indication of seal failure>? thanx

Re: condensation in lower unit?????

Sounds like its definately got a bad seal .To pinpoint loaction have LU presure and or vacuum checked.I would just simply drop lower unit and change all of the seals if it were mine.Driveshaft,shift rod,and propshaft,and carrier "O"ring.

Re: condensation in lower unit?????

What kind of water pressure do you have in the hose. The pressure of some city water systems is pretty high. I have a shut-off valve on the end of the hose and just open it part way until the engine is started.<br />Something to think about before the o-ring replacement.

Re: condensation in lower unit?????

Hose water pressure has no effect on propshaft seals ,nor will it pressure up the exhaust housing cavity that houses the shift rod seal.

Re: condensation in lower unit?????

Your first post doesn't make sense. Water is heavier than L/U grease and should have come out first not last.

Re: condensation in lower unit?????

not city water its well water <country>. dont know what his pump psi is. but still the lower unit was flushed with new lube before final lube was pumped in, than it sat until this last wknd.<br />when we did the intial drain the amount of water was only about 2 to 4 teaspoons. thats why condensation was suspected. due to low lying swampy area. condensation dew in early mornings is unbelievable(spl).<br />-<br /> but then it would make sense that a seal mite be bad because the air should be stabilized in a sealed environment. i think that sounds logical.

Re: condensation in lower unit?????

Generally, oil is not hygroscopic, meaning it does not absorb water. That is why the water separated out of the oil when it sat for a while, before you drained it out. But the oil should float on top of the oil, so water should drain out first. <br /><br />And no, condensation not cause. Condensation would require damp air to travel into the lower unit, and then condense on the inside metal surfaces. Since there is no air entering or exiting the lower unit, and there shouldn't be any air or exposed surfaces inside, condensation is pretty difficult.<br /><br />If there is water in the l/u, the first thing to do is replace the seals.

Re: condensation in lower unit?????

i would think that if it was mixed during operation. thats why im confused. i will have to test in a cup to see if water dripping down side like condensation into gear lube if it would remain on top if undisturbed or sink to bottom.<br />thanx for indirectly suggesting that.

Re: condensation in lower unit?????

while i go start the test, let agree that the water is heavier but could it have pooled somewhere in unit only to come out as level was dropping?<br />- did the quick test in a cup with 1/4 ridge from bottom, found that not all droplets sank to bottom, some stayed on top while smaller ones stayed in middle. also that the water did pool on ridges.<br />could be water pooled on some casting material the last time he flushed. coming in at seals around drive shaft.<br />will let him know if he is not going to replace seals to have it vaccum & pressure tested. thanx for your help.

Re: condensation in lower unit?????

There are seals not only at the prop shaft but also at the drive shaft. The water pump sits on top of the gear case. Excessive water pressure can and will force it's way past the drive shaft seal and into the lower unit. But since you have well water I would suspect that this is not happening unless that seal is bad. Some lower units do have cavities under the water pump where water can pool.

Re: condensation in lower unit?????

the pressure is pretty strong coming out of hose as i checked it visually. had i of known he is planning to leave as is and let burn up/break/ruin<br />i never would have posted.