1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Diff breather extension - question?

Discussion in '80-Series Tech' started by CodyRx7, Aug 28, 2006.

  1. CodyRx7

    CodyRx7

    Messages:
    1,860
    Likes Received:
    6
    Joined:
    Nov 26, 2005
    Location:
    Prescott Valley, AZ
    I just added the J-spring, L-shock lift to my 97 LX.

    I've seen some posts where people just add new longer length hoses...

    Since it appears to just be fuel line, or replaceable with fuel line - would it work just to add a little inside connector and then another few inches of hose?
     
  2. Rookie2

    Rookie2

    Messages:
    3,022
    Likes Received:
    79
    Joined:
    Dec 15, 2003
    Location:
    Knoxville
    Sure, you can easily splice it with a barbed brass fitting and a couple of hose clamps. The diff. breather mod write-up has a couple of spots where there is a three way tee splicing two lines into one as they're collected and extended into the engine bay.

    :beer:
    Rookie2
     
  3. Doc

    Doc

    Messages:
    5,917
    Media:
    33
    Albums:
    1
    Likes Received:
    362
    Joined:
    Apr 26, 2004
    Location:
    Utah
    12 extra inches of hose might be cheaper than the hose coupler. Just replace the entire legth, and that crappy flapper valve.
     
  4. Beowulf

    Beowulf

    Messages:
    12,529
    Likes Received:
    52
    Joined:
    Mar 27, 2003
    Location:
    Somewhere in the foothills...
    There are 2 issues with the factory diff breathers.
    1. The flapper valve creates a vacuum which can potentially allow water to be sucked into the diff housing through the hubs. Frankly, I see this as a minor issue but it was one of the first things I "fixed" because it was well documented and easy to do. The vacuum also pulls birf grease past the oil seals into the diff housing.

    2. The factory locations for the ends of the breathers is too low for most water crossings. To "fix" this requires a longer hose than you are suggesting. I see this as the bigger issue; especially if you do any water crossings more than about 10" deep.

    -B-
     
  5. Nay

    Nay

    Messages:
    4,542
    Likes Received:
    404
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    Are you saying replace the flapper valve box on the front hose, i.e., throw it away and just use longer hose?
     
  6. Doc

    Doc

    Messages:
    5,917
    Media:
    33
    Albums:
    1
    Likes Received:
    362
    Joined:
    Apr 26, 2004
    Location:
    Utah
    flapper valve box?

    My 93's flapper valve was about the size and shape of a pencil eraser, and did not function as designed. Easily replaced with a 'crank case vent' style filter from Oreily's. Extended into the engine bay.
     
  7. CodyRx7

    CodyRx7

    Messages:
    1,860
    Likes Received:
    6
    Joined:
    Nov 26, 2005
    Location:
    Prescott Valley, AZ
    Ahh, that seems simple enough. I will have to follow the lines to see the whole current setup.

    I did forget to attach the front breather hose to the fitting on the axle the other day, and drove maybe 20 miles. This morning there was maybe 10 drips of fluid which came from the open breather.

    My question now then...if the fluid can come out from pressure (I assume) - what would keep it from coming out of a "crank case vent" which is just a tiny air filter?

    Is the hose length what keeps the fluid from having enough pressure to come out the top?
     
  8. Nay

    Nay

    Messages:
    4,542
    Likes Received:
    404
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    My '95 has a little box that the hose plugs into that is connected to the frame, and then vents through the top of that box.
     
  9. Beowulf

    Beowulf

    Messages:
    12,529
    Likes Received:
    52
    Joined:
    Mar 27, 2003
    Location:
    Somewhere in the foothills...
    Yes, aided by a higher location like in the engine bay. Have you read this thread?

    -B-
     
  10. Beowulf

    Beowulf

    Messages:
    12,529
    Likes Received:
    52
    Joined:
    Mar 27, 2003
    Location:
    Somewhere in the foothills...
    The rear breather should look like this before modification.

    [​IMG]

    The 80 series rear diff breather valve after modification is shown below;

    [​IMG]

    -B-
     
    Last edited: Aug 28, 2006
  11. YOTAFAN

    YOTAFAN

    Messages:
    355
    Likes Received:
    3
    Joined:
    Nov 15, 2005
    Location:
    Charlotte, NC
    Say, I see how the tranny diff breather feeds into the tranny dip stick, but what does it do there? Does it "breath" thru the end of the tranny dip stick? If I extend these lines, do I need to cap off where it fed into the tranny dipstick?
     
  12. Nay

    Nay

    Messages:
    4,542
    Likes Received:
    404
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    Interesting...first time I had come across this. What are the benefits of connecting all of the breathers together beyond raising them all into the engine bay? Seems it would be easy to just use an extended hose on the two diffs and be done with it? Or are the tranny/case breathers vulnerable as well?
     
  13. Beowulf

    Beowulf

    Messages:
    12,529
    Likes Received:
    52
    Joined:
    Mar 27, 2003
    Location:
    Somewhere in the foothills...
    I feel the tranny & Xfer breathers are OK at the top of the tranny fill tube. At that location they are maybe 3" below the inner fender location shown in George's pics. There are no other benefits to relocating them (tranny & xfer.) Someday I may add another couple of tees and take them all up to the single location but my water crossings are few and far between since most of my off-road trips are in New Mexico and surrounding areas.

    -B-
     
  14. Rookie2

    Rookie2

    Messages:
    3,022
    Likes Received:
    79
    Joined:
    Dec 15, 2003
    Location:
    Knoxville
    It's just a bracket/mounting point above the tranny and transfer for the ends of those lines to live. It does not penetrate into the tranny dipstick tube.

    :beer:
    Rookie2
     
  15. Nay

    Nay

    Messages:
    4,542
    Likes Received:
    404
    Joined:
    Aug 17, 2004
    Location:
    Colorado
    I don't see much water either in Colorado wheeling (used to have a 3' crossing, but those trails were destroyed in the Hayman arson).

    I was looking to extend my front diff breather and ran into this thing. What is it? The breather hose connects into the bottom and it has a port on the top, and it is attached to the inside of the frame.
    Diff Breather.JPG
     
  16. Beowulf

    Beowulf

    Messages:
    12,529
    Likes Received:
    52
    Joined:
    Mar 27, 2003
    Location:
    Somewhere in the foothills...
    That's the breather "black box" that others have mentioned. I pitched it and used the rear brass breather valve as depicted and modded and mounted in the engine bay. Both breather lines run to the one breather valve.
    -B-
     
  17. alkaline747trio

    alkaline747trio

    Messages:
    4,577
    Likes Received:
    11
    Joined:
    Feb 2, 2005
    Location:
    Albemarle NC
    I extended my rear breather to a T in the front where the front and rear now tie together, go through the factory mount clamp and is zip tied where the air-pump silencer used to be. Tiny crankstyle filter on top.
     
  18. Erratic

    Erratic

    Messages:
    354
    Likes Received:
    0
    Joined:
    Dec 4, 2005
    Are you referring to the "teller county car wash''? On the Hackett gulch trail. I loved wheeling and dirtbiking out there when I lived there. Now I'm stuck in NH with a lot of stupid mud! So extending the breathers is necessary for me. Do they really need a filter on the end? I was thinking about just running them to the air box and putting a bulkhead hose barb on it. Tie em all together and terminate it there. But do they really need anything on them?
     
  19. alkaline747trio

    alkaline747trio

    Messages:
    4,577
    Likes Received:
    11
    Joined:
    Feb 2, 2005
    Location:
    Albemarle NC
    As long as they are getting clean air and not throwing axle pollution into the intake you shouldn't have a problem.
     
  20. IdahoDoug

    IdahoDoug

    Messages:
    8,848
    Likes Received:
    247
    Joined:
    Aug 9, 2003
    Erratic,

    Look at the dust and grit that settle in your engine bay. Want some of that in your differentials? Didn't think so. A pop on fuel filter for a lawnmower is about $1.50 and cheap insurance at that.

    DougM
     
data-matched-content-rows-num="2,1" data-matched-content-columns-num="1,4" data-matched-content-ui-type="image_stacked" data-ad-format="autorelaxed">