Oil Extraction

[Sootydog]

Hi,
     I have previously used a vacuum pump extractor to remove the engine oil (D1-30) but is it suitable for the saildrive.  I usually get the oil out from below but she wont be lifted this year. How long would the pipe need to be, or is this a silly question?  I assume you would put the pipe in the filler hole.  Apologies in advance for such basic questions.
   Thanks

[Salty]

It’s about four years since I last used that method to get as much oil as I could out of the saildrive. I had a long thin tube about a metre long and I remember that it didn’t all get used due to something preventing it from going further down. In consequence not all of the oil was extracted. Since then the boat has been ashore each winter where I’ve been able to use the bottom drain plug. It was worthwhile to run the engine with the prop in gear for a while before sucking the oil out as that warmed the oil in the saildrive making it easier to extract.

[Rampage]

I’ve used a Pela pump to extract the oil from a 120S-E Saildrive.  Feed the tube down through the dipstick hole, don’t force it but twist it about a bit and it’ll get more or less to the bottom.  I used the thinner of the two pipe provided with the pump, same one as I use to extract the oil from the engine.  Takes a bit of time as the oil is fairly thick but it got just about all of the old oil out: left perhaps 50 ml behind based on the amount extracted.

[Yngmar]

Depends on the model of your saildrive. On our 120S-E it is definitely not possible to get the tube to the bottom of the leg, as there are two sharp turns and nothing to guide it through there and into the bottom half.

On later (130+) models it may be possible to get the tube down into the leg, as there is a more direct path, but even so you'll not reach the absolute bottom. The saildrive is not like an engine, it has no oil filter, so any debris will collect in the bottom of the leg and can only be properly drained with the drain screw there. If the debris is not removed, the inner seal and prop shaft will wear faster.

Removing these particles is really the only reason for doing an oil change in the first place. Therefore it is of little benefit to doing a partial oil change from above. Just haul out next year, drain the oil from the bottom drain plug, check/replace seals and inspect the shaft for wear.

On our saildrive, the drain plug should also have a small magnet, that gathers any fine metal parts (from wear) and prevents them from rapidly wearing seals and shaft.

[Salty]

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There is little benefit to doing a partial oil change from above - probably so little it's not even worth bothering. Just haul out next year, check/replace seals and inspect the shaft for wear.
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I agree with Yngmar on this, if you don’t get all of the oil out you may not know whether there is any water remaining in the vicinity of the prop shaft bearings
Also, apart from the occasions where I’d used a tube down into the saildrive to try to suck out as much oil as I could, and where I’ve known that the tube I’ve been using has not reached the bottom of the drive leg. I have otherwise drained the oil out each year through the bottom drain plug, and on many of those occasions the oil has appeared like new to the point that I begin to qwonder whether I could have left it in use for another year.
The oil drained off however is never disposed of until it has had a couple of days at least to allow any water held in suspension to have settled out, that way I get a heads up on any water that might have leaked in to the drive leg.