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Water leak around dripless bearing

Posted: July 15th, 2017, 6:49 pm
by crquisto
Carver 406 - I have a pretty significant water leak between my port dripless shaft bearing and the blue hose behind it that is supposed to keep sea water from entering. I hit a log yesterday (no vibrations afterward, but it did kill the port engine so I had to restart) and that seems to have caused the problem. The leak is at a rate of about 15 gallons per hour, so the bilge pumps can easily keep up. I am now in port so have closed the through-hull, but the leak continues, so it must be coming from the stern. Looking at the area, there is a 1/4" gap between the raised part of the bearing and the blue pipe, while on the starboard side they abut each other. Can I loosen the clamps and push the bearing further into the blue pipe, or just tighten the clamps? Can I safely repair this in port? Any suggestions welcome. Thank you.

Re: Water leak around dripless bearing

Posted: July 15th, 2017, 8:45 pm
by Viper
A picture would really help. Is it a face seal or a lip seal type dripless?

Re: Water leak around dripless bearing

Posted: July 15th, 2017, 11:27 pm
by crquisto
I don't know the difference between face seal an lip seal. The sea water supply and exhaust hoses attach to connections that are mounted on a ring that is about 1 inch wide and appears to be black plastics. There is stainless ring on the power side of that black ring. To the stern, the black plastic has a shoulder that narrows its diameter by about 1/4"-3/8". The blue pipe, as I called it, fits up around that narrowed plastic and there is a 1/4" lateral gap between the blue pipe and the wider segment of the black plastic. I can squeeze the blue pipe easily and feel that the narrowed part of the black plastic appears to extend all the way back to the point where the drive shaft exits the hull. I have tried to attach a photo
IMG_6289.JPG

Re: Water leak around dripless bearing

Posted: July 15th, 2017, 11:32 pm
by crquisto
Looks like the photo made it. Water is coming in between the blue pipe and the black plastic. I tightened the hose clamps around the blue pipe and reduced but did not stop leakage.

Re: Water leak around dripless bearing

Posted: July 16th, 2017, 9:45 am
by Viper
The only reasons for it to be leaking there that I can think of is loose clamps, a leaking hose, or the assembly is cracked. Are you sure the leak is coming from under the blue tube hose or is it coming from one of the fittings or around the shaft and just running down giving you the impression the leak is from the hose?

I can't quite tell if this is a face seal or lip seal but face seal units have a bellows type hose as they must be pre-loaded so that there is constant pressure between the carbon ring and the stainless collar. That makes a difference if you want to reduce that gap. It looks like a Tides Marine lip seal type log. If it's a Tides Marine lip seal unit, you can loosen the clamps and push the seal assembly back.

The stainless collar at the front, does it have a couple of set screws in the side?

Re: Water leak around dripless bearing

Posted: July 16th, 2017, 9:07 pm
by crquisto
Thanks, Viper. I cannot see or feel any set screws on the stainless ring.
I think you are right that it is a Tides unit. I have all the original parts list and in the propulsion section, right after the two 1-1/2" shafts it shows two "SHFTLG: 1-1/2 X 2-1/2TIDES". Looking at the starboard side, there is no gap between the blue sleeve and the black shoulder, so I guess the port side should be the same. I didn't have a lot of time today but I did try to loosen the clamps a bit and slide/stretch the sleeve to close the gap. No luck. Maybe have to loosen the clamps some more? It just looks like the sleeve is too short to push up tight in a "lip seal".
The sleeve is pliable and I can feel the water in it and the hard shaft log underneath it. When I squeeze, water leakage increases - definitely squeezing out in the 1/4 inch gap forward of the blue sleeve. I tightened the clamps and yesterday I closed the port engine cooling thru-hull. That has cut leakage off, so I guess the water was coming thru the cooling system and not directly thru the bearing seal. Any further inputs appreciated. Would it just be sensible to replace the shaft log, and could that be done in port?

Re: Water leak around dripless bearing

Posted: July 16th, 2017, 9:44 pm
by bud37
I can say I have no experience to comment on the shaft log, .....but if it were my boat and I hit a log while underway hard enough to stall that side and create the damage to that area you have, I believe I might pull the boat and inspect the whole area underneath. The running gear in these things is expensive and would not want to cause further damage. For peace of mind...what its worth just my two cents.

Re: Water leak around dripless bearing

Posted: July 16th, 2017, 10:39 pm
by crquisto
Thank you, Bud 37. I've run through that scenario in my head because it doesn't make sense that I could hit a log that hard and not have any vibration from shaft and/or prop. I was running with the sync engaged and chopped the master at impact. I'm thinking the strike may not have even been on the prop and that the sync may have chopped the port engine all the way to cutoff. I'm due for a bottom scrape anyway so I'll ask my diver to look around carefully. He's got a lot of experience.

Re: Water leak around dripless bearing

Posted: July 17th, 2017, 10:51 am
by AaHubb
Crquisto you should be able to loosen the clamps and tap the end piece back so it fully seats in the hose. That part is not secured to the shaft.
..Aaron

Re: Water leak around dripless bearing

Posted: July 17th, 2017, 1:23 pm
by crquisto
Thanks AaHubb. Gonna try that today. Wish I knew what all this stuff looked like the inside.