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OMC Upper stringer pressure test

allenpoteau

New member
I'm new to the site and need some help,

I own an 85 OMC with a 5.7 and lost my upper stringer last summer. I recently bought a used and wish to re-seal the unit. I bought a seal kit part # 87650 which replaces 982949.

I'm told to pressure test to ensure all is well, I plan to tear down and get to work in the next few days and any advice would be appreciated. Can I pressure test at home? Any advice during the re-seal procedeure as I have no manual.

Thanks to all
 
Any advice during the re-seal procedeure as I have no manual.
my advice is to get a factory manual and follow it to the letter, especially with regards to shimming the upper into the exhaust housing at reassembly - and it will show you how to pressure test too.

I would probably pressure test before bothering to reseal...the used one might be fine - put a w/p impeller kit in it - I wouldn't worry too much about the sealing - the leaks in uppers is more often due to incorrect shimming into the exhaust housing
If it fails a pressure and vac test, then reseal it and check housing for cracks if it fails

When changing the w/p kit- look to see if the old impeller hsg is cracked/broken from ice - if it is, look carefully at the gear case- they sometimes crack too with rain/snow turning to ice if the drive is stored tilted over the winter

I have these testers for pressure and vacuum - not cheap, but they work great. There are some cheaper kits on eBay usually - can't vouch for them, but probably work fine too.
pressvac.jpg
 
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Thanks hystat, goin with the Seloc due to my time frame. Is it possible to just regulate my air compressor? If so what psi?

Thanks again
 
10 psi is what I use, but it's time that tells seal condition - you need to trap the pressure in there which requires the threaded adapter and valve. Vacuum is actually a more important test than pressure. Pressure test tells if gear lube will leak out, but vacuum test tells if water will be pulled in when the drive cools after operation.
 
looks like pg 10-94 of the SELOC book has the shim procedure for the upper to exh. housing cover clearance. That's the biggie with water in those uppers I find. Especially when swapping gearboxes around -many people don't realize there are shims in there that affect how the o-ring on the exh. cover seals the upper. Also affects steering.
 
Thanks again hystat. Got my manual ordered today. I'll get to looking for a vacuum and pressure tester. I didnt realize how important these gearcases are until a little research first.
 
Hopefully in the next day or so I'll be working on my upper stringer which brings me to another question friends, Is there a textbook way to adjust the shift cutout switch? My Seloc gives only a brief descripion only.


Thanks all
 
Definately you will need a good book on repairing/adjusting the shifter does it have the two cable setup the inside of the box behind the engine can be intimidating there are several adjustments that need to happen in order. change any parts as necessary hopefully the cables to the gearbox are good.

Yes it does have the shift converter and I do have a good manual for set up. Just curios about the shift cutout switch.
 
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