Larsdrop seal leak

[SVmelodie]

Attached pics of my Larsdrop seal setup (attached to Isuzu 3LB1 "suzie" engine 25hp).

The seal is leaking a little when in gear/running, no leak when stationary

I have fitted little DIY drip catcher as you can see, as a band aid while I try to sort this out. At the moment I'm really just trying to understand this system, this is my first cruising yacht (32ft keeler)

How should the valve with the blue lever be adjusted? I understand its water supply to the seal. It has been in this position since i've owned it and never touched it for 2 years, I don't think the seal was leaking back then. It seems strange that it is in a near closed position?

Do you have any links to good resources on how these systems work? or any suggestions?

[wmcunninghamii]

I have a Lasdrop on a 1 inch shaft. Mine is leaking pretty badly underway but dries up slowly at anchor or the dock. In theory the seal is self aligning so I am wondering if my problem may be a "stiff " coupling between sell enclosure and stern tube. Like you, I am troubleshooting.

The vent hose you are seeing is designed to vent air and allow water to surround the seal and lubricate it. That hose needs to be a. open and b. end point above the waterline else the boat will flood. I don't know why the installer elected to place a ball valve (I assume that what it is) in the vent line but if it is closed you will not be lubricating the seal if there is any air up in the stern tube. Oh, wait, that might be a burping button which allows you to fill the housing by opening the vent long enough for the seal to flood then close the valve and you are in business. I don't like it though. If you forget after a rough passage under sail the seal could be running dry as a result of air captured in that stern tube.

This is my second Lasdrop seal ( the actual seal I am using same housing). The first lasted 5 years before it got to leaking at an annoying level. This new one has about 300 hours on it after replacement 1.5 years ago. It definitely should not be leaking but the replacement was a nightmare for various reasons unrelated to the seal so something may have gone wrong during the install in my case.

The thingies up in front of the seal housing is your spare seal. This is a cool feature. If you need to replace the lipseal inside the housing it can be done at sea. You disassemble the front of the housing, hook the seal out of its seat and cut it with dikes. You then slide your spare into the seat re-attach the front plate and you, sir, have a new seal in place. This is one of those things you will want to think about first, plan your attack, and accomplish briskly for obvious reasons.

By the way, Lasdrop humans have been very accessible at their tech support line. I would call them here in the States and kick your issue around. I have found them to be pretty willing to help as much as they can.

You can contact Lasdrop technical support by calling (800) 940-7325 toll free or (231) 794-5070 internationally. Their website is also helpful with tech info

https://lasdrop.com/index.php/dryseal/

One final point. The Lasdrop lip seal is a wear item. I used to do some multi thousand mile offshore races and had to lock the shaft to prevent prop spin 24/7/365. Putting the boat in gear was very gnarly with 6 or 7 kts of boat speed. I thought I would tear the tranny out. I have a two blade fixed prop. It was necessary to engage/disengage at least once a day so I could do charging without spinning the shaft. I used a stick wedge to stop the shaft and that stick would literally start smoking when I applied pressure to the shaft to slow and stop it. That was interesting! Anyway, if you don't have a folder be mindful of this wear potential.

[Lepke]

The valve supplies forced lubrication for the stern bearing. If the bearing is wearing then it needs more water. If not then the same or less water. The seal leaking isn't because of the lubrication water. The seal probably could be replaced.

Many small boats don't have forced lubrication.

[wmcunninghamii]

Me again. I don't think I had the blue thing right. The vent tube goes from the seal through the blue thing and to ...what is that? some sort of exhaust manifold or water inlet/outlet or?

This mystery manifold may be the source of the cooling water. So instead of my description this set up may be rigged to pump water TO the seal vs venting air to allow flooding. Anyway, interesting I look forward to hearing the story.