OMC Cobra Pressure Test/Seals Question

I will be pressure testing my two '89 Cobra's (5.7) this evening. The process that I have is to pump up the drive with 7lbs. for about an hour, check for leaks and steady pressure. If OK, then pump up to about 15lbs. and maintain for about 2-3 hours, then check for leaks.<br /><br />I have two questions. First of all, I do get some water in both drives. I notice this when draining the gear oil in the fall.<br /><br />1) Can I assume I will find a leaky seal (if any) without doing a vaccum test?<br /><br />2) How difficult is it to change the seals. I have heard that the lower half is easy, but the upper can be diffucult. I have a quote from the local OMC repair shop for $500 for each drive (to replace seals). That seems high. Is it worth $500, or is this a DIY "no brainer"<br /><br />(My outdrive experience is limited to pulling, lubing, etc.. although I have replaced engines before - just to give you my capibilities background.)<br /><br />I have a clymer manual.<br /><br />Thanks

Re: OMC Cobra Pressure Test/Seals Question

$500.00 is CHEAP........<br /><br />It's a Very Involved Process,...... Not a DIYer.....

Re: OMC Cobra Pressure Test/Seals Question

drain oil before pressure test<br />you don't have to wait an hour a few minutes is ok<br />pressure test will only show were oil can leak out<br />vacuum test also required to see were water can leak in<br />resealing upper requires special tools

Re: OMC Cobra Pressure Test/Seals Question

You can't assume anything without a vacuum test,but why do we keep doing these tests.<br /><br />Water in the gearcase is not divine intervention.<br />Either you put it there on a refill,or it leaks.<br /><br />DHP

Re: OMC Cobra Pressure Test/Seals Question

Well thats my exact problem. I think it is divine intervention. I did a pressure test, and vacuum test on my port side (which did have some water in it), and no leaks whatsoever. The ujoint bellow was completely dry, and in good condition. During the refill, I completely drained the old oil, for about 1.5 hours, and filled with OMC Ultra (something).<br /><br />The only thing I can think of, is that I changed this in the Fall, and just now did the test. Perhaps the seals reseated (???)<br /><br />-Dave