Oil Breather on a Yanmar 6lypa-Stp?

I have twin 2005 Yanmar 6LYPA-STP 370HP diesel engines. We purchased this mostly fresh water boat last year from the original owner.

On the starboard side of the engine, at the aft end of the intercooler, there is a nipple with a 5/16” hose off of the nipple. The hose on both engines is about 18 “ long and has a small rag stuffed into the end of the hose. The stuffed rag is saturated with oil, but not dripping.

The nipple is not an add-on, it was casted in the after-cooler part itself.

Here’s a pic: http://i258.photobucket.com/albums/...p 430 Aft Cabin Trawler/Oil Breather port.jpg

Does anyone else have this set up? Is this normal?

JimL

Underneath the oil filter there is a shallow basin that fills with oil when you remove the oil filter. That hose is to drain that basin. Look closely and you will see.

David

If you look the area over carefully I believe you will find this to be a drain for the cavity below where the oil filter attaches.
When changing oil I try to get as much oil as possible to drain back before removing the filter
I have found punching a hole in the top near the closed end of the filter alliws air to enter and some oil to drain back.
I then spin the filter to the hole is down and catch any drainage in a container.
Even with the above some oil will drain into the open cavity of the casting. .. I leave the container I used in the area and put the clear hose in it.

Alternately you should be able to spin the filter and let the oil drain to the cavity and then via the hose to a container.

Either way saves a larger amount of oil running over the cooler into the bilge

Nice boat.

I would change out those stuffing boxes with dripless, the current setup is an accident waiting to happen.

Greetings,
Mr. MM. "...the current setup is an accident waiting to happen." On the contrary. MY opinion is drip-less stuffing boxes are an accident waiting to happen. At least with the traditional type as Mr. jL has there will most probably be lots of warning in the unlikely event of a failure. The gland can readily be repacked pretty well forever and if the connecting hose is in good shape, the seal should never fail. If the bellows on a dripless seal ever fail, it's catastrophic with no way to stem the inflow.

Really, tell me how many have you seen fail? I have them for 20 years (along with numerous friends) now and my back end engine area is not covered with salt like his or highly corroded clamps (look at his pictures), if you wants to replace unit in kind that fine, but everything that is highly corroded needs replacing.

RT Firefly said:

Greetings,
Mr. MM. "...the current setup is an accident waiting to happen." On the contrary. MY opinion is drip-less stuffing boxes are an accident waiting to happen. At least with the traditional type as Mr. jL has there will most probably be lots of warning in the unlikely event of a failure. The gland can readily be repacked pretty well forever and if the connecting hose is in good shape, the seal should never fail. If the bellows on a dripless seal ever fail, it's catastrophic with no way to stem the inflow.

Click to expand...

At the risk of a substantial derail, I have seen two failures in the last 7 years on two different installations. The first instance, a motor mount failed (~6 years old) and when the motor was in gear it threw the alignment off far enough to disturb the seal. When the motor was in neutral there was no issue. In the second instance, a friends boat had the collar's set screw back off and the collar slid allowing water to pour in pretty good. I still like dripless boxes but they can fail just like everything else.

Marlinmike said:

Really, tell me how many have you seen fail? I have them for 20 years (along with numerous friends) now and my back end engine area is not covered with salt like his or highly corroded clamps (look at his pictures), if you wants to replace unit in kind that fine, but everything that is highly corroded needs replacing.

Click to expand...

Greetings,
Mr. MM. I haven't seen any dripless seals fail BUT the potential for sinking is far greater with a dripless seal than with a traditional packed type stuffing box if either fail. I'm in the "If it ain't broke, don't fix it" crowd.

Anecdotal article: Dripless Shaft Seals | | PassageMaker

Thanks everyone.

Don was on spot. The small reservoir that collects oil when you change the filer has a small canal that drains the oil through the nipple. I almost missed it the first and second time I looked, but felt it with my finger. Thanks Don.

Porman, you have an exceptional looking and well made boat. We should compare notes off line.

Regarding the dripless seal vs packing glands - I'm staying with my current system b/c I don't have the time right now to install another system. Where I'm located I don't have access to a range of marine mechanics, and I am more comfortable doing the work myself if time permits. Thanks for your comments. The value of this forum is invaluable.

JimL