Extended diff breather, oil in filter

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Dec 17, 2007
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Was topping up engine oil the other day, and noticed my $2 fuel filter on my extended front diff breather is 1/2 full of diff oil.

Should I be concerned?
Whats a possible cause?
 

flintknapper

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I'm not a fan of using cheap fuel filters at the end of a 'vent line'. They are designed to trap fairly small particulates and as such can clog easily from dust or a mist of oil that is expelled over time as the diff heats up and pressurizes. As the filter becomes saturated...the issue is exacerbated.

Instead I use a small compressor muffler or vacuum pump breather. They have adequate air flow and usually a felt (filter/attenuator) that doesn't clog up.

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1904419


Breather.jpg
 
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Joined
Dec 17, 2007
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Cool, tidy looking solution.

Been thinking about this. I think I may have water contamination in the oil. It looks a little nasty, and the truck has done a few water crossings recently.
Thing that water vapour may have pushed oil up the breather.

I'm gonna dump the diff oil and see what I've got
 
Joined
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Olathe, KS, USA
Was topping up engine oil the other day, and noticed my $2 fuel filter on my extended front diff breather is 1/2 full of diff oil.

Should I be concerned?
Whats a possible cause?
I had this happen too. Cant find my full response right now, but will try to remember to track it down in the next day or two.

There's a reason it happened.
 
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Thanks guys.
Was thinking water has either raised the oil level, or caused it to foam up and raise the level.
Will drop the oil on the weekend
 
Joined
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I couldn't find where I previously posted about mine having done the same thing.

Anyway:
Keep the fuel filter in the VERTICAL section of the vent hose up by the brake booster. This will allow any oil to drain back down into the axle if it does get pushed up there.
After mine pulled grease from the knuckles since the breather was clogged, I forgot to drain out some of it and as it heated and expanded, it pushed a bunch of oil up the tube and clogged my filter due to the level being too high.
 
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Jul 20, 2004
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Chandler, AZ
I'm not a fan of using cheap fuel filters at the end of a 'vent line'. They are designed to trap fairly small particulates and as such can clog easily from dust or a mist of oil that is expelled over time as the diff heats up and pressurizes. As the filter becomes saturated...the issue is exacerbated.
...
They cost ~$1ea, replace as needed,,, the ones on my truck are ~15yrs old, never been replaced.:meh:
 

flintknapper

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They cost ~$1ea, replace as needed,,, the ones on my truck are ~15yrs old, never been replaced.:meh:
Filter/Muffler is like $3-$4 on ebay, and are designed to flow AIR. Never replaced mine either in 19 years. People use fuel filters because they are too lazy to source a more suitable item for the job, not because of cost hopefully.
 
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Apr 9, 2013
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The clear fuel filter gets my vote - it's right on the firewall and I can and do look at it all the time. The clear aspect makes inspection constant and allows me to always be informed. An opaque option is inferior in that regard, and I don't see a need to switch. Just my two cents, I'm with Tools.
 
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I do like having the clear filter visible. I wouldn't have seen this if I had an opaque filter.
Having said that, my rear diff breather is tucked in the quarter panel out of sight.
 

flintknapper

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The clear fuel filter gets my vote - it's right on the firewall and I can and do look at it all the time. The clear aspect makes inspection constant and allows me to always be informed. An opaque option is inferior in that regard, and I don't see a need to switch. Just my two cents, I'm with Tools.
Your fuel filter is also opaque, the filter in your trans...you can not see, the fuel pump sock is out of sight. None of these things need to be constantly checked. Just check them from time to time. Neither 'Tools' or I have seen a need to change either item in many years. IF you do water crossings often or are neglectful about changing out diff gear lube or servicing your birfields...then yes you might check whatever filter system you choose regularly.

My point was that there are products designed to flow air (or vent) that should work better than a fuel filter. Not asking anyone to change...and don't care what you run. Just making folks aware there are choices.
 
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