Can I pressure test alpha one gen 2 upper and lower sperately

[dufrain]

Im trying to find a pesky leak. Here is my oil before and after i ran it for a few hours . It was new oil yesterday. I had pulled the outdrive off it the day before to try to find the leak.I pulled the prop and there was no water in the driveshaft boot . I drained it then put a new small o ring between the 2 units and it held 20 psi for around 30 minutes. I pulled a vacuum with a mighty vac it held also. I sprayed soapy water on the seals couldn't find a thing. While i had separated i pressure tested the lower ,it held fine, The upper I tried to test separate air would leak at the vertical driveshaft seals without the shaft in place. Should air leak from there with no shaft in place or to test separated does this area need a plug installed there. .

 

[Rick Stephens]

I can't think of any effective way to test separated. You could use a plug the same size as the shaft to plug it but I can't think of the point. Connected up, they have to seal. Last time I went looking I used a horse water trough and dumped the whole thing in with pressure. Eventually found the bubbles. Have to be able to turn the shaft as well. Which is easier in a trough and see bubbles than on a bench.

 

[nola mike]

Yes. Plug the passage between the drives and test as normal.

 

[achris]

Quite correct. The lower seals in the top box are sealed by the lower drive shaft. Easier than a trough is to just spray each suspect area with soapy water. .. Bubbles up nicely.

Chris. .....

 

[dufrain]

Ill check again I cant find a single leak, i had the outdrive hanging on an engine stand with a special adapter. I spayed soap everywhere and spun the shafts no bubbles. Can the water pump put water in the oil under it

 

[achris]

Ill check again I cant find a single leak, i had the outdrive hanging on an engine stand with a special adapter. I spayed soap everywhere and spun the shafts no bubbles. Can the water pump put water in the oil under it

Not without a leak showing up on the pressure test... Although, if you are getting water in, do a vacuum test.. Pull about 6 or 7 inches and see if it holds.

Chris........

 

[dufrain]

I pulled 12 or 15 lbs with my mityvac and it held. I have the sample oil in the deep freeze now to see how much it slushes up

 

[achris]

lbs is pressure, vacuum is measured in inches of mercury. So I assume you pulled 12 to 15 inches. If that held, a seal is not how the water is getting in.

 

[dufrain]

I guess you are right on the inches i never looked on my gauge to see if it said inches. Is there any way the water could be getting in or could the gl5 oil i used really whip up like that in color , its been 30 hours or more and its still not separated and looks yellow like in the pic, ill check the sample in the freezer in the morning. Thanx for the help

 

[achris]

Use a crackle test... (do a search on it )

You should be using Mercury High Performance Gear Lube, nothing else!