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Pressure testing aq270 outdrive

M

mrdopes

Contributing Member
Hey fellas,

After pulling my boat out of storage for almost 2 years, I've been in the process of getting her water ready again... im running twin aq130c's mated to aq270 drives.

I got the engines going wonderfully, then tackled the outdrives.... The port drive is good, but the starboard drive is giving me issues....when changing the oil in it, i saw that I had some water contamination...

I made a good looking tool out of a fuel pressure gauge to pressurize the drive and look for the leaking seal, but cant seem to find the proper sized fitting to thread into the dipstick hole so i can attach the pressure tester...

I've tried the local hardware stores, and the local autoparts stores, that they are clueless as to what I am talking about... Basically i need a hollow bolt or grease fitting that will thread directly into the dipstick hole.

I am hoping that someone on here could hopefully help me out and tell me exactly what thread size, or part name, i should be looking for.... maybe point me in the right direction to find one?

Someone else said that it is a 3/8 coarse thread, is that right?

They sell the actual pressure tester on ebay for 70 dollars, but money is tight and I would rather spend that 70 bucks on seals at sierra marine! lol.

Also, one other question that i had, while i was messing around with it today, i noticed very small trace amounts of metal dust in the drive oil.... the only reason that I noticed it was because the sun happened to be directly overhead and the sun reflected on oil, making it sparkle a little...

there was not that much, no large flakes or shavings, and i would 'assume' that some would be normal, as there are metal gears in there spinning around....but I wanted to ask people with a little more experience before I put too much more money into non-critical areas... like i said, it was not even noticeable, unless i let the sunlight hit it the right way...

anyways, any help with either of these issues would be a great help.

Thanks!
 
The test is a "Leak-Down" test, and you need the correct equipment.
Look at this! The seller's name is Tom. Good guy. He can set you up with a tester that does both pressure and vacuum..... of which is what you want.
http://cgi.ebay.com/ebaymotors/Inbo...at_Parts_Accessories_Gear&hash=item3f0127ee09

For the pressure test, the drive must be drained of oil!

Remember.... it's called a "leak-down" for a reason!

Shift mech seals. if not green in color, are very likely old, and need to be replaced. For about 12/14 years they have been green and are double lip!
If you have a brown one, it is old! If you have a black one, it is probably original! These are a maintenance item!

Main drive gear seals also fail if bellows maintenance has been deffered in the past. This is involved because the main drive gear bearing box must be removed!
Post back if you intend to do this.... there are some do's/dont's.

In some circles, I'm known as the PDS NAZI..... so I'm going to suggest that you replace your PDS (primary drive shaft) bearings.
On these engines, the PDS is capable of aft removal!
Bearings/seals can be purchased from a major bearing supplier inexpensively.
.
 
Thread size are the same for the V/P, Mercruiser ans some OMC if that helps. I think they are right about it being 3/8 thread. Buying the test kit is really the best way to go as no fab is needed. This way also pinpoints the leak and a whole seal kit, expensive, is not needed.
A little touch of color in the sun is very normal, chunks not so much. Shift shaft seal and P/S seals are the most replaced. Pull the U/J bellows back and check for water, if it's there, that's the entry point and you have bigger problems.
 
thanks guys,

I did u joints, bellows, seal and bearing directly behind the u joints on the outdrive side, right before I put the boat in storage.

Is that one of the bearing/seals that you fellows are referring to?

I will do whatever needs to be done. But first I need to find out where that water intrusion is coming in from...

I actually have a leak down kit in the garage for automotive, so i just need to find a threaded fitting that will hook up to the outdrive. Im going to give a local marina/shop a call tomorrow or tuesday and see if i can my hand on a fitting that way.

I just see no use in paying 70 bucks for a new pressure test kit when i have one that just needs the fitting....

In terms of the other bearings and seals that you guys were referring to, could u give me names, or part numbers if possible, so i can price the parts out and start researching the repair/tear down process... i'd appreciate it.

Thanks for all your help, it's nice to be able to ask for help and actually get it. I wish all the other forums that i've been to were as concise as marineengine.com.

Thank!
 
as for the bearings parts that I am interested in, just the ones that you would think should be looked at and changed after sitting for almost 2 years... pretty much just a 'should check/change' to do list, if you would...

thanks!
 
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