New trick to stop oil filter leak- learned the hard way
12-24-2016, 01:22 PM
#31
Rennlist Member
O-Ring seals are different than gaskets.
Just like our SCUBA diving O-Rings, it must be able to move and fill in the O-Ring channel.
In contrast, a gasket uses the high sandwiching pressure to seal
When you treat an O-Ring like a gasket you can cause uneven sealing surfaces which leak. It is counterintuitive but true, don't reef down on an O-Ring, it will seal on its own under pressure
Just like our SCUBA diving O-Rings, it must be able to move and fill in the O-Ring channel.
In contrast, a gasket uses the high sandwiching pressure to seal
When you treat an O-Ring like a gasket you can cause uneven sealing surfaces which leak. It is counterintuitive but true, don't reef down on an O-Ring, it will seal on its own under pressure
12-25-2016, 12:45 PM
#32
Rennlist Member
O-Ring seals are different than gaskets.
Just like our SCUBA diving O-Rings, it must be able to move and fill in the O-Ring channel.
In contrast, a gasket uses the high sandwiching pressure to seal
When you treat an O-Ring like a gasket you can cause uneven sealing surfaces which leak. It is counterintuitive but true, don't reef down on an O-Ring, it will seal on its own under pressure
Just like our SCUBA diving O-Rings, it must be able to move and fill in the O-Ring channel.
In contrast, a gasket uses the high sandwiching pressure to seal
When you treat an O-Ring like a gasket you can cause uneven sealing surfaces which leak. It is counterintuitive but true, don't reef down on an O-Ring, it will seal on its own under pressure
Per Merriam-Webster:
Definition of gasket: a material (as rubber) or a part (as an O-ring) used to make a joint fluid-tight
Face Seal
Radial Seal:
So a face seal can be dependent on how tight the enclosure is torqued. A radial seal is independent of tightening torque. The O-ring on the Porsche filter housing is a radial seal type. Once the O-ring is engaged into position between the housing and the engine, the torque that is applied does not matter. I did not have a good photo of the housing and O-ring so I borrowed this one from Pelican:
Once the housing is fully seated, making it any tighter does not change the sealing capability. What Carl has theorized, and I tend to agree, is that as the housing is threaded in, the O-ring has to turn into the vehicle. In certain conditions, which seem to be influenced by temperature, the O-ring sticks in places and becomes uneven in cross-sectional diameter as it stretches. As an analogy, imagine taking a rubber band and stretching just one part of it. That part gets smaller in width compared to the non-stretched part. The smaller part does not fill the gland sufficiently (has reduced or no compression) and therefore can't seal as well and might leak some.
By threading the filter housing back and forth a few times as Carl describes, the O-ring is allowed to seat evenly and therefore seals uniformly. I have personally never seen this happen in any other application or car but it is a reasonable theory considering a few people have had the issue. Carl's solution does work so I am not going to question it much beyond that!
12-26-2016, 12:34 AM
#33
Guys here is another idea that you may have not thought of, Drill a hole in the filter and drain it so you don't have oil going everywhere you don't want it. Now remove the filter once it has drained. You can buy the filter and housing as one unit. I use super lube on the O ring and threads and never have a problem..
12-26-2016, 12:49 AM
#34
Race Car
Thread Starter
Sonorous , thanks you did a much better job than me explaining it. It seems to be a problem when the engine is hot the filter really gets hard to fully seat even with the oring and thepads lubed. Cold it seems to seat easier. Regardless I'm using the seating technique I described . No down side. Carl
