Diff Breather Extension Mod
 

As many of you have heard/read me complain, we recently got our wheel seals replaced, due to a clogged breather. During the job, they also replaced said breather.

Well, I did the extension mod today, and I started thinking. Does doing the extension create enough of a restriction to cause hte seals to blow again? I mean, there are bends and such that wouldnt be there if only the pumpkin-top breather were used.

Fuel hosing is pretty stiff. You'd have to have a lot of slack to cause enough kinking to restrict the breather from doing what it is originally intended to do.

Besides, I think you're thinking of this the wrong way. It's not that the air has to travel all the way from the differential, up the tube, and to the breather... the air is already in the tubing itself so it's just the breather.

hmmm... maybe that isn't coming off as well as I'm hoping.

no. it'll be fine as long as you don't collapse the hose.

Actually, be sure that there are no downward dips in the breather hose as it runs from the axle to the vent filter. Why? Read my page for more info: http://www.4crawler.com/4x4/CheapTri...html#Breathers

The whole intention of extending the breather is to not let water in. By extending it you're simply just giving it a pocket of air as the diff expands and contracts. The air in the tube will just simply go up and down with the expansion and contraction of the diff. You could have 1,000,000 ft of hose and it wouldn't mess up the breather.

Actually... when I did the mod, I did have an excess of hosing and looped it around. At Robinhood's suggestion I cut it short because of the possibility of oil clogging the line in a lower point of hosing.

Seems to make sense to me so I figured what the heck...

FWIW, your front diff has an extended breather, all FJ-60 and FJ-62's had both breathers extended at the factory and the 1988 Jeep Wagoneer axle I have under my truck now had a Jeep version of an extended breather, now it has a Toyota version.

Those 3rd Gen axle seals suck, there are tips to make them last longer and even a double liped seal. Basically it's a design flaw and some leak and some don't. Mine leak so don't feel bad.

Not to steal anyones thread but I had a quick question about this breather mod. I've seen a few write ups where people locate the factory breather valve higher up. Some people re-use or replace the factory valve where others get a small crank case or valve cover filter.

My question is, is there any harm in using the small filter method over the factory breather valve?

A filter is better that the stock breather, IMHO. Why? Breather is basically a check valve, allows air out but prevents water (and air) from getting in while stopped; while moving, the cap jiggles and allows for air exhange in and out. Why is that an issue? Imagine driving up to a deep water crossing with hot axles. Drive into the deep water and slowly cross and the air inside the housing starts to cool. As it cools the breather seals off and a partial vacuum is pulled inside the housing. Get enough vacuum combined with the hydrostatic pressure of the water (1 PSI for every 2 ft. depth) and you can have water leaking in past a weak axle or pinion seal. A filter will allow the axle housing pressure to remain equalized as the axle cools.

And why a filter and not just an open hose? Helps keep dirt out of the hose and housing and also keeps things like spiders and other bugs crawling in and setting up housekeeping. Something like that can get in and clog the vent line and that case cause oil leaks due to the pressure buildup.

All covered on my web page that I posted a link to above.