What is inside an oil filler/breather cap?

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Lord Sparky

Lord Sparky

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I am going to rinse out my oil filler/breather cap with some Simple Green, blow it out, then fill/drain it with engine oil. Does anyone know what is inside the oil filler/breather cap? Some kind of metal mesh that holds the oil and filters dirt?

Oil Cap.jpg
 
Typically a media of filter type material. It will absorb atomized engine particulate. 65'
 
I’ve done this and the mesh always comes apart and if you shake it the mesh will fall out of it. So now I don’t want to use it on the info engine any more. So I don’t clean them now.

YMMV
 
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You could try using methanol (methyl alcohol) it will loosen debris, remove varnish build up, not destroy the filter media, and it will dry without needing a water rinse.
Alternatively you could use isopropyl alcohol (rubbing alcohol is too dilute) but it takes a bigger amount to do the same job as methanol.

You could shorten they drying time by using gentle compressed air.
 
413 said:
I’ve done this and the mesh always comes apart and if you shake it the mesh will fall out of it. So now I don’t want to use it on the info e any more. So I don’t clean them now.
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What was the mesh made of? When I look in the bottom, I see a (looks like) metal mesh screen with 1/4" square holes. Don't seen anything when I look in the air cleaner side tube.
 
Lord Sparky said:
What was the mesh made of? When I look in the bottom, I see a (looks like) metal mesh screen with 1/4" square holes. Don't seen anything when I look in the air cleaner side tube.
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Metal mesh like a pot scrubber. Coarse steel wool.
 
Like any other degreasing.. it gets soaked in 100LL around here. Gas will clean it up and not have you worried about ruining anything. Simple green ain't so simple all the time...
 
All the ones I have seen have a course steel wool like material in them.

Mine 67 dart 273 does not seem to have anything in it.

I don't like that cause the pickup point is before the air filter in the snorkel so it sucks unfiltered air into the engine.

I have thought about filling it but was hesitant for the reasons listed above.

Maybe a plastic fiber mesh oiled down would be the ticket
 
I just run a can of carb cleaner through mine, usually come out clean before the end of the can and it dries quick. I’m not a fan of using water or water based cleaners for this application.
 
Same stuff crack heads use in their rock pipes, don't ask how I know
 
DFX 340 Duster said:
You could try using methanol (methyl alcohol) it will loosen debris, remove varnish build up, not destroy the filter media, and it will dry without needing a water rinse.
Alternatively you could use isopropyl alcohol (rubbing alcohol is too dilute) but it takes a bigger amount to do the same job as methanol.

You could shorten they drying time by using gentle compressed air.
Click to expand...
I wound up using denatured alcohol. It really wasn’t very dirty. The only thing that came out were orange paint chips I guess from the oil cap scratching the valve cover paint. I poured some engine oil inside but didn’t get the feeling there was any kind of filtering material in there.
 
Dana67Dart said:
All the ones I have seen have a course steel wool like material in them.

Mine 67 dart 273 does not seem to have anything in it.

I don't like that cause the pickup point is before the air filter in the snorkel so it sucks unfiltered air into the engine.

I have thought about filling it but was hesitant for the reasons listed above.

Maybe a plastic fiber mesh oiled down would be the ticket
Click to expand...
Yes, why not just filter the air going into the valve cover at the air cleaner, then no need at the oil filler cap?
 
Lord Sparky said:
Yes, why not just filter the air going into the valve cover at the air cleaner, then no need at the oil filler cap
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I agree, not sure why Chrysler did not do that except inside the air filter it would be a bit of a lower pressure zone than atmosphere due to air filter restrictions.
 
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