Brand New Leaking Oring - Out Of Options - What's Next?

[rfdfirecaptain]

I encountered this problem while working on this repair job: http://forums.iboats.com/showthread.php?t=543693

Basically, I had gear oil leaking out through my exhaust chute of my DP-D1 outdrive. It failed a pressure test, losing all air pressure in about 3 seconds. When I reassembled the lower housing to the intermediate housing I used 3 brand new orings. I used a little grease to hold 1 of the orings in place and to make another oring lie down flat in its machined groove. Slowly and evenly I started tightening the 4 main bolts. Once these bolts were tight I inserted and tightened the aft 3 remaining bolts. I pressurized the outdrive and lost all air pressure within about 1 second. I could hear the air leaking out through the exhaust chute (same as my original problem). I torqued all 7of the bolts just a little more and repressurized. There was no change.

I removed the lower housing, wiped all surfaces clean, repositioned all 3 orings about a quarter turn, reassembled and torqued bolts again just as stated above. Now I am holding pressure for about 6 seconds until completely evacuated. :facepalm:

I?m at a loss for what to do next. I cannot tighten the bolts any further. The oring around my drive shaft is so thin it looks like there can be no more than 1mm of compressible height (above the edge of the machined groove it sits in) before the two housing surfaces are bolted flush against each other. I am sure these are the correct OEM orings and even had Don S. help me with choosing the right parts.

I guess the question I have is this. When you are sure you have the correct orings, and you can?t tighten the bolts any tighter what is the next thing to do in this situation? I?ve already prayed about? so that one is covered! Fortunately, I live near an oring manufacturer. I consulted them and have already purchased the next size up orings. Before I install these larger orings I just want to make sure I have exhausted every possible method of getting a tight fit with the OEM orings. Thoughts, ideas??

 

[Don S]

Re: Brand New Leaking Oring - Out Of Options - What's Next?

You don't need bigger orings, you put in new ones and that didn't stop the leak, tighting more is not the fix either. you need to find where the leak is coming from, and it's obviously not the orings.
You may have a crack in the intermediate housing, or the lower between the oil and exhaust passages. You're just going to have to look. No way to test that I know of.

 

[rfdfirecaptain]

Re: Brand New Leaking Oring - Out Of Options - What's Next?

UPDATE: I have said it before, Don you ARE the man! If not for your help over the past 3 years this boat that my family has enjoyed so much would have already been sold for parts. However, this is a first for me and is surely a rare occurrence here on iboats.com. Read on….

At first, I took Don’s advice and went so far as to disassemble all 3 housings of my DP-D1 outdrive. Based on Don’s recommendation I wanted to ensure I did the most thorough jacket inspection possible to look for cracks in the cast aluminum. That makes sense, but nothing noteworthy was found. Once again, with no other options I decided to go with the larger Orings between my intermediate and lower housings. Unfortunately, the exact sizes (ID and OD) were not readily available. Finally, I found a local gasket company that can custom make an Oring on the spot.

Here’s how they did it: They used Buna “rope stock” that was .017 (seventeen-thousandths) larger than my OEM Orings. They used a micrometer to get the ID and OD of my Oring groove. They cut the rope stock to the proper length and GLUED the ends together with Loc-tite adhesive. http://www.henkelna.com/cps/rde/xch...tredDotUID=productfinder&redDotUID=0000000I0U

Amazing! So today I learned how to make and Oring using some Oring material a razor and special glue that costs about $30 per ounce. The whole process took about 15 minutes. And the glue is so strong if you stretch the Oring it will break... but not at the glued connection!!!

I have installed the larger Orings and reassembled the housings. At a starting pressure of 15psi. I immediately dropped pressure down to 13.50psi. Thankfully that pressure has been holding steady for almost 2 hours. Multiple soapy water sprays have not revealed a single bubble.

I’m going to start searching the threads. Does anyone know right off the top of their head what the minimum pressure is to confirm a successful pressure test? I don’t think 15psi. is an achievable option for me, but 13.50psi, if it holds steady, seems pretty good to me.