Clogged diff breather tube blowing axle seal?

[68whiskey]

So when I got my truck last year, the right rear axle seal was bad. I had an independent mechanic replace it along with the bearing, ABS rotor, snap ring, etc. About a few months later, it was leaking again. When I took it back, I was told the seal had snapped in half and they were baffled as to why it happened. They replaced the seal, all was good again. Fast forward to yesterday. I took my truck in to the dealership (the only place working on it for any reason at this point) for an oil change, alignment, and tire rotation. They came out about half way through and said that the axle seal was blown out again.

With the axle seal blown, it saturated the brand new OEM shoes and drum that were just put on not too long ago. The service writer said that the diff breathing tube was clogged, and the pressure was blowing the seal out. So..to take care of the diff breather, axle seal, new shoes, and to resurface the drum, its going to be $500. Money aside, does this sound like it could be the issue? I know the stigma that the dealership has on here, but I've always been treated fairly and have never had to take anything back there because of work that they have done. A lot of things I can do on my own, but I just don't have the time.

Any thoughts or opinions would be appreciated, thanks!

 

[mtbtim]

So when I got my truck last year, the right rear axle seal was bad. I had an independent mechanic replace it along with the bearing, ABS rotor, snap ring, etc. About a few months later, it was leaking again. When I took it back, I was told the seal had snapped in half and they were baffled as to why it happened. They replaced the seal, all was good again. Fast forward to yesterday. I took my truck in to the dealership (the only place working on it for any reason at this point) for an oil change, alignment, and tire rotation. They came out about half way through and said that the axle seal was blown out again.

With the axle seal blown, it saturated the brand new OEM shoes and drum that were just put on not too long ago. The service writer said that the diff breathing tube was clogged, and the pressure was blowing the seal out. So..to take care of the diff breather, axle seal, new shoes, and to resurface the drum, its going to be $500. Money aside, does this sound like it could be the issue? I know the stigma that the dealership has on here, but I've always been treated fairly and have never had to take anything back there because of work that they have done. A lot of things I can do on my own, but I just don't have the time.

Any thoughts or opinions would be appreciated, thanks!

A clogged breather can absolutely cause a failed axle seal. As the differential heats up, there is a build-up of pressure and the pressure needs to go somewhere. If the breather isn't working, the pressure will find the path of least resistance and that's the oil seals on either ends of the axle housing.

But, here's what you tell the service writer. They are suppose to know that a clogged breather can cause this issue. The fact the seal failed another time before shows they didn't figure out the culprit the first time. They SHOULD NOT be charging you for this. As professional mechanics, they should have picked up on it the first time the seal snapped in half that this isn't a normal thing. Because they failed to address the root cause of the axle seal failing, they should be willing to do the work for free and also pay for all the replacement parts. They need to admit they screwed up and take responsibility.

 

[97LtdToy]

Clogged breathers are pretty much the most common cause of leaky axles seals on any vehicle.

Sent from my SM-G900W8 using Tapatalk

 

[m0ist]

I second that they should accept the cost of replacement. If the dealer did the work the 2nd time your seals were replaced, you should still be in warranty.

Also, I think it's worth noting. Unless your shoes are worn out you shouldn't need to replace the shoes and resurface/replace the drums. Tell them to clean them w/brake cleaner and reuse.

Have him route some tubing off your diff breather so it doesn't get clogged again.

 

[mtbtim]

Clogged breathers are pretty much the most common cause of leaky axles seals on any vehicle.

Sent from my SM-G900W8 using Tapatalk

I don't necessarily agree with this. If you're talking the rust belts of the country, maybe. In areas that don't have rust issues, I think the main culprit is time. The bearing gets worn out which increases the play and that extra play working on an old seal eventually causes it to leak.

 

[68whiskey]

A clogged breather can absolutely cause a failed axle seal. As the differential heats up, there is a build-up of pressure and the pressure needs to go somewhere. If the breather isn't working, the pressure will find the path of least resistance and that's the oil seals on either ends of the axle housing.

But, here's what you tell the service writer. They are suppose to know that a clogged breather can cause this issue. The fact the seal failed another time before shows they didn't figure out the culprit the first time. They SHOULD NOT be charging you for this. As professional mechanics, they should have picked up on it the first time the seal snapped in half that this isn't a normal thing. Because they failed to address the root cause of the axle seal failing, they should be willing to do the work for free and also pay for all the replacement parts. They need to admit they screwed up and take responsibility.

Thanks for the input! It was an independent mechanic that replaced the seal the first two times, maybe i could have been more clear on that. When they pulled the wheel at the dealership yesterday and saw the seal had blown, they diagnosed the issue right away. Thats why I figured id hop on here just to be safe. The independent mechanic didn't catch it the first two times the seal went. The dealership got it right away, which is why id pay a little more at this point for people that know the ins and outs of these trucks.

 

[68whiskey]

I don't necessarily agree with this. If you're talking the rust belts of the country, maybe. In areas that don't have rust issues, I think the main culprit is time. The bearing gets worn out which increases the play and that extra play working on an old seal eventually causes it to leak.

I agree with you, I think this was the problem when I first got the truck since there is really no rust to speak of underneath the vehicle, or anywhere for that matter. The seal that was in the axle when I got it was simply worn out. The second time, however, it had clearly snapped in half, and obvious pressure issue looking back on it.

 

[68whiskey]

I second that they should accept the cost of replacement. If the dealer did the work the 2nd time your seals were replaced, you should still be in warranty.

Also, I think it's worth noting. Unless your shoes are worn out you shouldn't need to replace the shoes and resurface/replace the drums. Tell them to clean them w/brake cleaner and reuse.

Have him route some tubing off your diff breather so it doesn't get clogged again.

From what I've been told by many people, you can get a lot of the fluid off of them with break cleaner. But when the shoes heat up again, fluid will continue to come out. Apparently the shoes will retain a lot more fluid than brake cleaner can get out of them. Same with the drum, brake cleaner will only do so much. Resurfacing the drum can get past where the fluid was able to penetrate.

 

[3bears]

I have been told by many, including a 30 year retired Toyota dealer mechanic, clogged breather is the #1 cause

also agree, just brake clean wont get all the oil out of the shoes. what we used to do is soak them, cook them, soak them again. but that's when I was cheap and broke and young

 

[mtbtim]

I have been told by many, including a 30 year retired Toyota dealer mechanic, clogged breather is the #1 cause

also agree, just brake clean wont get all the oil out of the shoes. what we used to do is soak them, cook them, soak them again. but that's when I was cheap and broke and young

I still think it depends what area of the country we are talking about though and how the vehicle has been driven. If you're in the rust belts of the country or you regularly off-road in muddy conditions or do lots of water crossings, I think the incidence of a clogged breather must be higher. On the West Coast, in areas where it doesn't snow, I think the incidence of a clogged breather being the culprit is much less. I've done 4 axle seal jobs now and none of the failures was due to a clogged breather. If you count my rig that I paid through the nose for at my local dealer, that's a total of 5 that I know of that the breather wasn't the cause.

The breather is a very simple mechanism with very little that can go wrong with it unless it get's a lot of corrosion and seizes up. But, for sure I will continue to make sure I check every breather to confirm it's working correctly.

 

[Scramble]

It is the #1 cause & it doesn't have to be in the rust belt. Dirt + water will cause rust & clogging without salt present.

 

[csp]

The dealership got it right away, which is why id pay a little more at this point for people that know the ins and outs of these trucks.

This issue isn't specifics to 4Runners or Toyotas. The independent guy should have checked the breather the first time.

 

[68whiskey]

This issue isn't specifics to 4Runners or Toyotas. The independent guy should have checked the breather the first time.

Agreed. Either way, I know it'll be done right this time and I won't have to worry about it again.

 

[catrains]

this a Toyota the breather is a piece of metal that does rust. also mounted on the rear diff a very dirty and water whacked area with mud salt etc.... so then the breather fails on these as Toyota installed them..

NOW on my GM truck the breather is a plastic/rubber tube that goes from diff box to the fuel fill pipe area.. the breather part is plastic and protected somewhat by the gas cap door area..

even though this GM breather is in this mounted set up some have had the box bore hole get box goop blocking the breather venting .. then the leaks on the seals at wheels or drive shaft input seal...

a skilled auto tech will always check for this with leaks ..
some when changing diff gear oil check for the venting tube to work ..

 

[SodiumFlouride]

Now you got me scared.
Anyone have a picture of this clogged differential breather so I can get down there to look for it?

 

[mtbtim]

It is the #1 cause & it doesn't have to be in the rust belt. Dirt + water will cause rust & clogging without salt present.

Well, I know a clogged breather could very well be the culprit for leaking seals but I'm just not buying the fact it's the #1 cause, at least not on the sunny California West Coast. I have experience with 5 axle seal jobs, one of them being my own rig, and none of the failures were caused by a clogged breather. So, I'm batting 0 and 5 with clogged breathers being the cause.

I still believe the main culprit is time. The bearings over time wear out and develop more play. With more play in the bearing, there's more movement in the axle shaft. The extra movement in the axle shaft puts extra strain on a tired and less pliable seal and it finally fails.

I'm pretty sure if you talked to a 30 year mechanic in San Jose, California, he's not going to tell you clogged breathers is the #1 cause for axle seal failures. So, I still contend this is more location specific and use specific. People who live in the rust belts of the country and those who off-road in muddy conditions or ford deep water crossings are going to be more prone to having a differential breather that ends up getting seized up from corrosion.

I did a Google search for the reasons axle seals fail and I didn't find a resounding theme that a clogged breather was most common cause.

So, I would ask, how are you so confident about this? I can only go by my personal experiences and what I've researched and I'm not seeing any proof what you're saying is gospel. Feel me?

 

[mtbtim]

Now you got me scared.
Anyone have a picture of this clogged differential breather so I can get down there to look for it?

It's very simple. Take a wrench or ratchet and socket and remove the breather on the top of your axle housing. Now try to blow through it. If you can, you're all good but you may as well throw in a new one since they're cheap. Or better yet, do the extended breather mod and get that breather protected from the elements so you don't have to worry about it becoming corroded and not working.

Here's a video if you're interested:

<iframe width="560" height="315" src="https://www.youtube.com/embed/tCGMa4vng_g" frameborder="0" allowfullscreen></iframe>

 

[Scramble]

Well, I know a clogged breather could very well be the culprit for leaking seals but I'm just not buying the fact it's the #1 cause, at least not on the sunny California West Coast. I have experience with 5 axle seal jobs, one of them being my own rig, and none of the failures were caused by a clogged breather. So, I'm batting 0 and 5 with clogged breathers being the cause.

I still believe the main culprit is time. The bearings over time wear out and develop more play. With more play in the bearing, there's more movement in the axle shaft. The extra movement in the axle shaft puts extra strain on a tired and less pliable seal and it finally fails.

I'm pretty sure if you talked to a 30 year mechanic in San Jose, California, he's not going to tell you clogged breathers is the #1 cause for axle seal failures. So, I still contend this is more location specific and use specific. People who live in the rust belts of the country and those who off-road in muddy conditions or ford deep water crossings are going to be more prone to having a differential breather that ends up getting seized up from corrosion.

I did a Google search for the reasons axle seals fail and I didn't find a resounding theme that a clogged breather was most common cause.

So, I would ask, how are you so confident about this? I can only go by my personal experiences and what I've researched and I'm not seeing any proof what you're saying is gospel. Feel me?

I'm going by personal experience & what I read on here. But I agree it's probably location & personal use of the vehicle.

 

[SodiumFlouride]

Here's a video if you're interested:

Thanks! Your video is great!

 

[MSRP.]

Bit of deferred neglect and maintenance.

Rear axles have both been leaking from both sides, soaked everything (ABS gear), drums, rear shoes, grease on the rims, the whole 9 yards.
Stopped leaking, probably leaked below the level where it will affect the rear axle seals.
Rear diff breather was definitely SHOT, in fact, it crumpled and became two pieces when I took it out with a deep 14mm socket.

Replaced with a new one from Toyota (teflon taped the threads like mtbtim), and filled 1 full quart (didn't start leaking from the fill). I purposely didn't do an extender, cause I'm not sure how much longer I'm keeping the truck., and while I never cleaned out the mess from the first round of leaks, looks like it has stopped leaking. I also didn't fill up until it leaks, because if it's going to leak, I'd rather it be half a quart than say 1.5 full quarts on my garage. Also, I've had amsoil gear oil sitting for a while that I was going to drain/fill the rear diff with a year ago, but when I opened the fill port back then, very new looking fluid start dripping out. Unknown age, but I did not want to replace such new looking gear oil back then.

With a confirmed non-operational rear diff breather replaced, is it possible for the rear axle seals to reseal properly? OR is it a case of "once they leak, they will have to be replaced"?
For reference: 99 rear locker with just over 120k miles.