Ford Lehman Oil Pan Breather Tube

[BradC]

This is more of a "for my information" type question.

I understand the purpose of a valve cover breather on a gasoline engine, but I notice there is what appears to be a breather tube coming out of the upper side of the oil pan on my Ford Lehman 120.

It is capped with what looks like an old style fuel tank cap that has a rubber gasket that fits down into the breather tube to stop it up, so doesn't appear to actually let anything "breathe" via this tube. The tube is approx 1 inch in diameter. It's located just under the Alternator and I can't find a picture of it in the manual.

Just curious about its purpose if someone knows and and can help educate me.

(Forgot to take a picture while at the boat, but can do that tomorrow if needed)

Thanks in advance.
Brad

 

[Russell Clifton]

Used to add oil to engine if you had limited access above the engine.

 

[rgano]

The breather and the mesh filter inside it was a feature of the land-side use of the engine, especially in tractors. A call to Brian at American Diesel will likely result in the suggestion that you plug it with a plumber's plug you can buy at Home Depot. I did that on my two FL 120s years ago.

 

[kchace]

My 135's have the same thing. My question is why plug it or even worry about it? It is part of the breather system and as far as I can tell works fine.

Ken

 

[PM]

There was a pretty lengthly discussion on this breather tube here on T.F. a while back. I will search it out when I am ready to act on it which will be some time this spring.

The gist of it was that some nasty oil and combustion by products are vented through the tube into the air intake. These noxious gasses are potentially able to damage your engine, especially a newer engine. The solution was to trap these gasses in a closed container, filled with bronze wool or similar. The liquid will condense out and you can occasionally dump it. The remaining air mixture goes into the air intake.

I like the idea and will try it later.

pete

 

[Xsbank]

There is always a crankcase breather because there is always some blowby. Also, because the engine is not mounted horizontally, if the engine is used at higher power settings, the boat raises its bow and makes the engine tilt even further resulting in the rear of the crankshaft splashing in the sump oil and causing the oil to foam and vapourize. Imho, this tilt is the root of the #6 failure.

Also if the engine has never had its dipstick remarked the tendency is to fill the oil to the full mark which will be incorrect, way overfilled. That’s why you need to measure the oil you put in then remark the dipstick. If you don’t, the foaming etc will rapidly use up the extra oil and puts an old engine at risk of a runaway.

If you find your oil level in your Lehman drops precipitously after an oil change, then stabilizes, chances are great your dipstick is marked wrong.