Curious How Oil Filter Seals Internally

Hi all,

Something I am curious about is how our cartridge filter seals internally? It is easier for me to understand how a spin on filter seals as it is enclosed and screws on to a raised point on the engine.

I believe our filter must seal on the bottom by pressing down on the small ring of the canister, and into the engine housing by the filter going into the male protruding inlet to the engine and pressing against the metal around the protrusion (photos attached and areas circled in red). I just wonder how well this seals.. with the canister filling up with oil it seems like some dirty oil would be able to find its way around the filter....Interested to hear from someone who understands this better.

 

Thanks for the response.

Yes I understand how the outside of the housing seals with the large O-ring so oil doesn't leak out, I am curious about the how the filter inside the housing seals in to keep dirty oil from traveling up the middle into the engine if that makes sense.

 

I'm not sure it does form a perfect seal. There should be some leakage to not starve the engine if the filter get's clogged up.

 

It's important to understand the oil filter system isn't designed to filter 100% of the oil going through it. As the oil continuously circulates in the engine, even if the filter just filters 80% of the oil each pass, it would have filtered all the oil after some time. This is fine because the bypass valve opens often anyway when you get on the throttle before the oil reaches operating temp (and viscosity).

 

Thanks, this is exactly what I was asking about...I did my oil change last weekend and I was looking at the housing and the filter wondering how it seals up inside the housing, but I was under the impression it does filter 100% of the oil. I thought a full flow filter was supposed to filter all of the oil...but sounds like youre saying it doesn't seal up enough to catch all of it, which makes sense by looking at the design. I guess it works ok given the high mileage some of these engines reach.

 

Thanks, I watched this video a couple of times previously, good video.

 

It is "full flow" but Toyota doesn't go out of its way to seal the internals with O-rings and gaskets, etc., as that would be a waste of time with the bypass valve opening so often under normal use.

It's the same deal with Toyota canister filters internally, the media has no end caps:



The Car Care Nut usually has good information, but he's wrong in this video. The bypass valve is actually the quarter-sized disc at the bottom of the center tube (as seen in my picture below). That disc is the bypass valve pressure plate and opens upward. The flexure spring looks to be designed for a high duty cycle.



I was able to get the center tube and coil spring in and out of the plastic filter cap without bending the tabs on the center tube base. The process is repeatable with no damage to the center tube.

 

The term "full flow" here means that the filter is directly in line in the oil system and filters the majority of the oil in the system in one pass. Obviously the filter has to be able to pass a large volume of oil with a minimum of restriction.

At the other end of the scale is a "bypass" filter that pulls off a very small amount of oil and runs it through a much finer filter. In this application the small volume of oil moves slowly through the filter.

Years ago Amsoil used to market a bypass system, it pulled oil from the oil pressure switch port through a small line (1/8" ?), ran it through the bypass filter and returned it to the valve cover, I don't know if that style system is still marketed.