Question about diff breather mod - why 2 way?

If you can breathe in and out through it, it IS a breather!
See my link for the mod. Part numbers photographed.

 

When I blow it flows fine, but absolutely nothing when I suck in....lol

 

Then it is not a breather.

 

Great. Well I only bought what ppl posted on here was a breather. So do you have a part number for one?

 

I used the part numbers found in the first post of this thread.

https://www.tacomaworld.com/threads/differential-breather-mod-for-dummies-pics.15686/

 

Well I ended up doing what another member did. I took off the diaphragm on the one I got, and drilled holes on the cover thing. And now it breathes both ways

 

I already advised you that my thread on the mod (link in my signature below) has photos of the parts and the bag with number shown.

 

I took care of it.

 

Old thread but still, am curious about this.
By putting a 2 way breather on the rear diff, when it eventually does suck in air do to the cooling of the internals and the system, wouldn't that also create a high risk of sucking in wet humid air (environment dependent), where the humid air now inside the diff would unavoidably condense and introduce water to the diff oil?

First post, uncertain how I'm gonna see replies lol

 

The diff isn’t completely full of fluid, it already has atmospheric air in it…assumably at relatively the same humidity as the air outside of it.

 

Humidity is not an issue (remember the engine is also sucking in that same air, but at a rate of 1,000,000,000,000× any amount an axle housing might suck in). However dirt & water intrusion is an issue.
Relocate the 2-way breather up high to where it's at low risk of being submerged and not directly in an airflow of dust and you should be fine (up behind & above the d-side tail lamp housing is a popular spot, and is where I've always put mine for years).

Welcome to TW

 

here's a link or 2.

https://www.tacomaworld.com/threads/my-differential-breather-mod-photos.111954/

https://www.tacomaworld.com/threads/differential-breather-mod-for-dummies-pics.15686/

You put it up high so no water gets into it - the oem on my truck was low and if you go through water it can get stuck and not breath and then you blow a seal and brakes get soaked with diff fluid.