Front Differential Breathers

Hi,

There are two breathers by the battery and I'm checking them to make sure they're OK. The cap on the one closest to the front spins freely. No problem. The one that is closest to the firewall can spin, but it seems to require more force from my fingers and isn't smooth at all. Is this OK? Or should I replace it? It appears to be a barbed hose connection so I think I would just pull it off and slide the new one in. But I don't want to do this if the new one behaves the same way. Thanks.

 

It's fine.
How freely the caps spins will have no affect on function.

 

Thank you very much.

 

"spins freely"

my man. A breather's functionality is determined by whether it breathes, as the name would suggest.

It is not a bearing.

 

Thanks. Is there a better way to check it? I think it's just a one way valve with a barb connection to the hose.

 

You remove it and check if it sucks and blows with your mouth or use a vacuum gauge tool.
stock is generally one-way.

I don't see why, and how a two-way is not better. That in and of itself may suggest to change to a two-way, if you find it is one-way. IF it isn't clogged and no-way.
They are cheap and easy to replace.

 

Yes: Go online or to a dealer and buy a new one and see if it acts the same way. If it doesn't: replace it. If it does: replace it anyway and call it a day. I'm guessing it costs less than $10?? Even if it's more: Replace it. Confirm whether they are both the same part number. (likely) Regardless anyway, if they are not: replace both of them. I'm assuming your '23 has relatively low mileage, but that doesn't mean you didn't get a sketchy part when it was built.

My PCV still rattled when I removed and checked it last spring: just not so good. $8.00 to replace it. PCV hose had a split starting at one end: Replaced it: $12. $20 total. Not bad for 134,000 miles of service. (OEM) parts

Let us know how you make out.

 

There is absolutely no reason to go replacing these, especially on a new vehicle, but as the OP probably has already noticed, these two breathers come off different diameter hoses, and will indeed, have two individual part numbers.
I replaced and relocated my rear, one way diff breather, due to it's low proximity to the ground, but having seen where these are mounted, I never gave them a second thought.
(I did replace the rear one-way valve with an open breather)


Front two for reference:

 

Hi,

I thought I'd share what I've found so far. I've been on vacation for a while. I'm surprised how hard it is for me to find out what stuff is and what the part numbers are. Hopefully this is helpful.

Toyota has a diagram they use to identify the two "breathers". They are identified in the drawing below as 41110R No. 1 and 2:




These correspond to these part numbers with descriptions. No. 2 is the skinny "filter assembly, air", and No. 1 is the fat "plug, breather":




As a refresher, here they are in the truck near the battery:




I came across a video on Youtube where the guy actually traces the skinny "filter assy, air" all the way back to the Automatic Differential Disconnect (ADD) system. Based on the helpful advice on this forum, I sucked and blew on this filter assembly to see what it does. I can suck, but I can't blow. Shields up for that comment. So it only lets air into the ADD, and doesn't let it out. In this fellow's case on Youtube, his ADD got filled with water from having water levels up in the engine. Note that my original concern was that the silver cap didn't spin nicely like I expected a breather to do. It's not supposed to. The silver cap just stays firm when you check it. Here's the ADD information:






Moving on to the "plug, breather", I haven't traced the tube back to the front differential but I assume it goes on to it somewhere. I can blow on this, but I can't suck it (opposite of the other one). And it has the silver cap that spins and bounces up and down like I expected.

Hopefully the part numbers and functions help somebody in the future. Mine appear to be normal unless I feel like disconnecting them from the hose and doing a physical check (sucking and blowing). I'll skip this for now.