CCV Filter Drain

casey87

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My Yanmar 6yl has a Racor CCV filter added from previous owner, the drain that Racor says should go back to oil sump is capped. Its collecting oil which is going nowhere and fouling the filter prematurely ? I just noticed that a bit of oil was collecting on the air filter - the output of the filter flow tube comes out (I think stock yanmar has the CCV tube just coming to the air filter, my set up is same except it goes through filter first). I can take a picture of the set up if helps.

Has anyone set up a bottle or something for the filter to drain the oil back to? How long are you guys getting out of these filters?

Thanks!
 

Genius

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I have one on my Cummins 6BTA. I just have a hose to a plastic water bottle. Very little to no oil collects. Yes, I understand you can plumb it back into the sump. Unless I had copious amounts of oil I see no reason to. This way I can monitor it. So far I have 300 hours on mine. It has a tell tale that will indicate when the filter is in bypass. My plan is to use that or 500 hours.
 

captjohn

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In a nut shell, it's basically a crankcase vent system (PVC), kind of like you have in a car, with an oil vapor separator. The oil was originally intended to return to the oil sump. Personally, I would do what Genius did, I wouldn't want that dirty oil going back into my oil sump. Plugging it up probably causes the oil to back up in the tube, and clogs the filter.
 

Genius

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it's not a filter in the normal sense of a filter. It is a coalescing element. I don't believe that oil is any different than what is typically in the sump.
 

WoundUpMarine

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goody

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I have one on mine it drains into plastic jar. I cut a hole in lid. It works
 

traditions

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Side Note One should be very careful not to plug the flow thru a crank vent, it has been known to take out crank seals with increased base pressure.Make sure there are no low spots for oil to collect.
 

AGL

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Small engines and gas auto engines use a check valve to maintain slight negative pressure in the crankcase. A check valve holds negative pressures of the fluctuations in crankcase pressures due to pistons moving. (less effective on multi-cylinder) My small Yanmar (non-turbo) didn't have a check valve between the valve cover and the intake, so I installed one.

So, I don't see how the systems in this thread achieve negative pressures. Why not?
 

Genius

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I've never heard about negative pressure cranckcases or the benefits of it. The open end of the system is to the intake which I imagine produces a slight vacuum. Your check valve may have something to do with carburetor engine / air regulated flow and don't understand the cross over to diesel engines. I do love how my 2 stroke snowmobile engine deals with blow by.....using reed valves to supercharge crankcase gases and a resonating exhaust chamber system to further supercharge the air fuel mixture.
 

AGL

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Here are some links on negative crankcase pressures.


A diesel doesn't have manifold vacuum, and indeed, with a tubo you have the positive pressure, but you could at least get some negative pressure with a check valve to help remove moisture buildup and blow-by as I have done on my Yanmar. Without that we're no better off than historical systems Crankcase ventilation system - Wikipedia
 

Genius

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sorry, I don't believe it. Improved ring sealing? It started out as an emissions thing, that's all its about.
 

AGL

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I agree with that, but it is a good idea to remove moisture and blow-by from the crankcase.
 
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