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breathers

Discussion in '40- & 55-Series Tech' started by fj40crusher, Oct 18, 2003.

  1. fj40crusher

    fj40crusher

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    Ok, reading all the posts on the 80's board about extended diff breathers made me crawl up under my 40. Looks like I don't have any kind of breather on it at all, just the nipple. It looks like there is a cap on the nipple coming out of the diff (it's a 74 40 series). Should I put breathers on them. Is that cap looking deal some sort of a valve?

    Recommendations? The 40 sees more deep water then the 80 does. Last time I swapped the fluid it was looking pretty nasty, thinking this might be the reason.
     
  2. Steel

    Steel

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    My 40 Axles came back from the rebuilder with breather lines, so guess it 's a good idea. You should aways change the fluid (in the front at least) after they have been submerged anyway.
     
  3. CruisinGA

    CruisinGA

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    Its probably more likely to be nasty from a leaky inner axle seal than anything else, however, that little nipple thing with a cap on it is a one way valve that is a horribly crappy design. You can pry off that little cap easily, and its possible to hose clamp a tube directly on the leftover stub for a breather, however, with this method the valve itself is still in place I belive, and there really isn't enough room for a solid seal between tube and axle.
    On the front, this is easy to fix.
    Unscrew the whole valve thing out of the axle housing, get a brass barbed fitting with the closest threads you can find to the original valve. Screw this barb in, with some thread sealer if you wish. Now you have a sealed connection between axle and end of tube.
    The rear is not so easy.
    As you have probably noticed, the one-way valve deal is part of the brake t-fitting. There is a writeup somewhere about how to get around this, brainstorming right now heres what I think-
    1) Just remove stock T from axle housing with one way breather. Install barbed fitting as outlined earlier, just let stock hang.
    2) get a new t, mount it somewheres else and run new brake lines; install barbed fitting as aforementioned.
    It think either of these two methods would work. I'm not sure. I'm getting ready to do breathers too (maybe tomorrow?) if so, I'll let you know what I find.
    Edit: oh yeah, use clear tube (available at any hardware store). That way you can see whats goin on.
     
  4. CruisinGA

    CruisinGA

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    Heres the actual article.
    I'd probably trust it more than what I said. :D
    I have to go to home depot anyway tomorrow so I'm gonna pick up the stuff to do it and I'll let you know how it goes if I do.
    http://www.ih8mud.com/tech/breather.html
     
  5. fj40crusher

    fj40crusher

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    [quote author=CruisinGA link=board=1;threadid=6470;start=msg52398#msg52398 date=1066528364]
    Heres the actual article.
    I'd probably trust it more than what I said. :D
    I have to go to home depot anyway tomorrow so I'm gonna pick up the stuff to do it and I'll let you know how it goes if I do.
    http://www.ih8mud.com/tech/breather.html
    [/quote]

    Cool, a parts list would be a beautiful thing!
    :cheers:
     
  6. fj40crusher

    fj40crusher

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    Would also like to know where you run the breathers too. I was thinking about running them all the way up to the engine compartment. I don't see any other way to get them high enough. Would it be an issue if they were that long (rear that is)?



    Scott
     
  7. CruisinGA

    CruisinGA

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    Nope length doesn't matter, as long as there are no kinks, etc.
    I also need to investigate adding a breather for the transfercase. (Has similar one way valve to axles).
    Remember to either run the tubes into a place with clean air (glove box, behind dash, air cleaner) or stick a small air/fuel/crankcase filter on the end of the hoses to keep gunk from getting in.
     
  8. 72cruiser

    72cruiser

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    one of my friends just rebuild the axles on his old school 4runner, and ran the diff breathers all the way up through the body and out near the tailgate. he just drilled a couple holes to shove the tube thru. you can't even tell that they're there.

    i'll ask him about it the next time i see him, but i think he got the whole setup from napa or pepgirls for 10 or 12 bucks. he said it was for some nissan truck, but it fit right up. not so sure about our 40 axles though.

    jonathan