Maybe Stupid Breather Mod Question

So I'm putting together all the parts for my rear diff breather mod and what I can't seem to reconcile is how to end the breather line in the engine bay. I've seen people use a small filter, and I like that idea and it seems to make sense to me as air can travel in and out of the filter. I also see a lot of folks that use the standard axel vent caps, but aren't those one-way valves and close under negative pressure.... thus causing the same problem you're trying to prevent? Just want to make sure I'm not missing something stupid obvious, and yes, I have searched TW and youtube for answers, but nadda.

 

The experts will chime in... but getting the valve up and above any ground water level is the main purpose. No matter what the valve does regarding pressure, it won't be under water to allow water to enter.

 

Why are you wanting to run the rear dif breather line to the engine bay, instead of installing the breather in a location closer to the rear dif?

 

you start off by saying your rear diff breather then say where do you end up in the engine bay? are you trying to run a line from the rear diff to the engine bay?

 

confused the heck out of me too...lol

 

Maybe he wants it next to the front diff breather haha.

OP, you should have a union at the diff, attached to the union is a hose that runs up wherever you wish (preferably at the rear haha) at the end of that hose would be a two way breather.

 

There’s a thread with part numbers. Make sure you read though, some guys were giving part numbers to the one way breather instead.

 

Here’s where I ran mine....



This is what it looks like under the truck



Link to the “kit” I used. I’m sure you could source the parts cheaper if you wanted to, but come on it’s like $20 lol

https://www.yotashop.com/toyota-off...990UA7O5KLRm9hXy6tyq_VM8bi8d6XDoaAh4HEALw_wcB

 

For some reason I found the kits after I installed my individually sourced parts haha. I ran mine behind the tail light. Can’t remember which side though.

 

You have a pretty dry spot behind rear left tail lamp. Only need 6' of hose vs double for a engine bay mount. You go to your favorite auto parts or Amazon and get a universal one that claims to be 2-way or disassemble oem and make it into 2-way.

 

Thanks!! Ordered!

 

Ran my “rear diff breather” to behind the tail light housing.

 

Thank you for those of you with helpful posts. Again, I didn't ask where to run it.... yes I know that many run it up to the taillight, the compartment in the bed, but I was choosing to run it to the engine bay as the filter I was looking at was too big for a clean install in the other areas.

Thank you to those of you that commented that there are two-way breathers as this makes a lot of sense, but all I was finding was one way which would, in my opinion, make the mod useless as the negative pressure would still cause water to get pulled in through the axel seals.

My new question if people would like to actually answer it, do the two-way breathers have any sort of filter on them, and might it be better to have an actual filter versus one of these two way breathers?

(EDIT TO ADD) I have looked and looked after reading that there are two-way ones, but have not been able to find any...links?

 

The cheap one from Advance or NAPA does not; it's basically like the oem one in my pic without the black rubber piece. You'd have to get an ARB or a crankcase filter to have an actual filtered media. You're not talking about a lot of air going in or out; just enough to displace fluid expansion when hot or contraction when cold. You could leave it open without issues either provided its in a dry spot.

 

This is what I bought.