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TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!===FIXED!===

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by dawson444, Apr 15, 2002.

  1. dawson444

    dawson444 1/2 ton status

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    My TH400 has been leaking ATF from somewhere really bad. Well today I think I finally figured it out, I had taken the tiny vent hose on the top of the trans and extended it to the firewall to keep mud and water out. Well I think that thats where it is coming from.
    What would cause it to come out of this vent hose?
    It is only when I am driving and the tranny starts to get hot, but a good bit of fluid comes out and usually gets on the exhaust pipe. I have already had one incident (small fire) so I need to get this worked out. Any responses/ideas are welcome. Thanks!

    ================
    FIXED!
    see new post
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  2. HarryH3

    HarryH3 1 ton status Author

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    The first thing to check is that the fluid level is correct when the tranny is hot. Overfilling can cause the fluid to come out of the vent when the tranny warms up.
     
  3. dawson444

    dawson444 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    Come on I need help! I want to try to get something done TOMORROW (Tues). I want to drive it, its getting hot, TOP OFF!!!
    Thanks!
     
  4. DesertDueler

    DesertDueler 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    Well when that happened to my Firebird. It has a th400 in it as well. It would pukke out of the vent even when it was a quart low. Mine was the torque converter. I had the tranny gone through since I beat the crap out of it and everything was good. My buddy replaced everything, but told me all the old parts were fine. I had it rebuilt for no reason, other than piece of mind. I would say try a converter first, then if that doesnt work, time for a rebuild. The most common thing to break in a th400 is the sprag.

    Dan
     
  5. Chaz88K5

    Chaz88K5 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    tmanofcali had the same type of problem...send him a pm because i cant remember exactly what he had to do to fix it...but it was something simple
    Chaz
     
  6. BILLY RAY

    BILLY RAY 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    PUT A CONVERTER IN, IT SHOULD FIX IT.
     
  7. dawson444

    dawson444 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    Convertor is almost new, has around 1k miles. If that.
     
  8. BorregoK5

    BorregoK5 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    If the fluid looks dark you might be generating too much heat from internal slippage (non converter type) due to worn plates or a failing pump/clogged passageways. If so, you might be boiling the atf and its just looking for an exit!
     
  9. BILLY RAY

    BILLY RAY 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    Well i don't know what to tell you. That was the problem with by buddy's and the trans. shop said they run it to this all the time. Sorrry i could not help or the new conv. could have a prob. try to talk to the guys you bought it from.
     
  10. dawson444

    dawson444 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    Well I worked it out, it had way too much ATF in it. I let some of it out and that fixed the main leak. Thanks for the suggestions.
     
  11. BILLY RAY

    BILLY RAY 1/2 ton status

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    COOL !!!!!!!!!!!!!!!!!!
     
  12. HarryH3

    HarryH3 1 ton status Author

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    Re: TH400 Leaking ATF Out of Vent Hose On Bellhousing! Please help!

    Sweet! You had the answer in 24 minutes. /forums/images/icons/cool.gif
     

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