Pressure Testing Lower Unit

[Brew2]

Alpha 1 Gen 2.

Had to top up resevoir a couple times this summer...so pulled off the drive and built a pressure tester per someone's previous post.

After putting in approx 11 lbs of pressure, it all leaks out in about 30 seconds.

Will try to confirm tonight that my tester connections aren't leaking, but assuming all is good there....do you just spray soapy water around the prop shaft seal to confirm a leak? Assuming you see bubbles, is there more than one seal that can be leaking in the lower drive? If so, how do you narrow it down?

If you don't find a leak around the prop shaft seal...is the next most likely problem the quad ring where the lower meets the upper drive....is there a way to test this?

Finally, I'm assuming that with the drive removed, the outlet on the drive unit that leads to the resevoir has a one way valve that would hold pressure...correct?

Thanks in advance.

 

[Don S]

Re: Pressure Testing Lower Unit

You did drain the gear lube out of the drive before pressure checking didn't you ??????
If not, you must. Otherwise the lube can mask the leak.

Then spray soapy water everywhere. The shift shaft, the seals on the vertical shaft can and do leak quite often. You can see them through the front of the drive.
The prop shaft and the quad ring are also possible leaks, along with the top cap orign, the input shaft seal and anyplace else you can think of.
Many on hear put the drive in a tub of water and look for air bubbles.

 

[Brew2]

Re: Pressure Testing Lower Unit

Thanks Don.

Yup...drained all the lube before starting this process. Like the idea of dunking the entire drive in a tub of water...guess I'm off to look for a big rubbermade tub.