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Are you supposed to "bleed" a new stack plate tranny cooler?*PIC'S NOW*

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by BobK, Sep 27, 2002.

  1. BobK

    BobK 1/2 ton status

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    Are you supposed to \"bleed\" a new stack plate tranny cooler?*PIC\'S NOW*

    I'm going to install a stack plate tranny cooler(28K) and wondered if you need to bleed it or if you just hook it up and go?
    I thought I read something about the need to bleed.
     
  2. Grim-Reaper

    Grim-Reaper 3/4 ton status Author

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    I mounted mine so that the the inlet and outlet were pointed to the side. I then plumbed the inlet at the bottom so that the air would push out. Never gave me an ounce of problems. If you mounted it inlets down I think it may be an issue.
     
  3. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    I did mine just like Grim. No problems...
     
  4. DPI

    DPI 1/2 ton status

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    I mounted mine similar to the way the factory oil cooler is mounted. Both inlet and outlet pointing down. Not that it really makes much difference, but heat rises so if your outlet is at the bottom of the cooler, you should be getting cooler fluid than the top. Just like a radiator, the inlet is on the top and the outlet is on the bottom. Oh by the way, I used 5/16" metal fuel line and hard plumbed my 28K cooler in. I did not use any rubber hose that will eventually blow out.
     
  5. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    In at the bottom, out at the top will help flush air out. Continuous tubes shouldn’t have any problem with both lines on the bottom as flow will flush any air trapped in the tubes. I’m not sure about stacked plates so, I played it safe and laid mine on the side. Both on top should work equally well, but I would be hesitant to put both on the bottom. Maybe it would bleed off the air, maybe not, I don’t know…

    As for the convection theory (heat rises), heat itself is just energy and doesn't actually "rise". It just “flows” through materials at different rates seeking equilibrium (yeah, I know, over simplified, but close enough). However, most liquids and gasses get less dense with heat and rise above cooler denser material (hot air balloons for instance), but I don't think convection will come into play in a cooler.

    Also, just for the record, radiators are fed from the top and pulled from the bottom so that the pump doesn't run dry. If it went the other way (in at bottom, out at top) then you would need a reservoir above the top hose fitting to keep the pump from running dry if the coolant got the least bit low. I think the only time you would find a measurable difference in coolant temperature top-to-bottom *due to convection* in the radiator would be when the engine is off for a bit. When the engine (pump) is running, the bottom will be cooler, but that is due to coolant flow through the radiator and heat transfer to the air.
     
  6. DPI

    DPI 1/2 ton status

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    I did indicate that the radiator inlet is on the top and the outlet is on the bottom. The factory oil cooler is installed with both inlet and outlet on the bottom and I have yet to have any problems with it or the tranny cooler.
     
  7. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    Yes, I saw your statement about the radiator, but I took it to mean that the design was to take advantage of convection. That’s what I was attempting to address.

    I also have the factory oil cooler, and you are correct, it does have both fittings on the bottom. Does it trap air? I don't know, but it certainly could. In fact, it seems likely (almost certain) that it would. There is no way to check and no way to bleed so, who knows. Does it cause any noticeable or serious problems? No, not that I've seen or can imagine. I don’t see how it could cause trouble (or be in any way directly observable) as long as the oil is allowed to flow. If air is in fact trapped in it, does it reduce the efficiency? Yes, it would have to since there is less usable transfer area. Same is true for any cooler, to get max benefit you must be SURE there is no air trapped which would effectively reduce the size of the cooler. Given the design, the only way to tell if it has trapped air would be to do some careful measurements of efficiency. It wouldn’t be the first time that GM has used a sub-optimal design that was “good enough” in order to simplify assembly or maintenance and/or cut cost. I'm only saying that I see a potential reduction in efficiency that can be eliminated by orienting add-on coolers differently. When adding a new piece, why not do the best you can and eliminate any potential problems? As for the factory oil cooler, I’m sure it’s better than nothing, though I likely don’t need it, and I don’t have the need or desire to try to improve it or determine if it is working at 100%. Heck, if it ever gives me any trouble I’ll probably ditch it. /forums/images/icons/laugh.gif

    Anyway, I’m not trying to pick at your post or anything of the sort. I just like to correct any post that I believe to be inaccurate or misleading. In that way, I and others learn more. Sometimes I also get corrected, and sometimes my corrections are corrected. /forums/images/icons/blush.gif Either way, we learn new stuff and avoid problems…
     
  8. BARRAZA

    BARRAZA 1/2 ton status

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    Russ
    While I agree that in a tranny cooler convection wont have any effect, you might be interested to know that some engines are cooled entirely by the effect of heated water rising in the engine and going down through the radiator. No water pump at all! Have that system on a 1947 John Deere M out in my barn. They used to call it a thermal siphon system. Has been working great for 55 years.
     
  9. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    Cool! First I've ever heard of a convection cooling system on an internal combustion engine. Live and learn eh? /forums/images/icons/laugh.gif
     
  10. BobK

    BobK 1/2 ton status

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    Thanks guys,I just wanted to check before the install.I'm bending up 5/16" hard lines from the rad tranny cooler to the new stack plate.I'm keeping the rubber lines to a minimum.I'll snap a pic when I'm done. /forums/images/icons/grin.gif
     
  11. BadDog

    BadDog SOL Staff Member Super Moderator Author

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    That's exactly what I did on mine. I built new lines from the tranny to the radiator so that I could hook them directly in without the cooler. Then I pulled the lower line and screwed it into another hard line that went through to the stacked plate. Then, another hard line from the stacked plate to back to the tranny. This makes it easy to completely eliminate either the external cooler OR the radiator cooler if need be (due to leaks/damage). And, there are only 2 short rubber lines in the whole system...
     
  12. BobK

    BobK 1/2 ton status

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    Well...here's how it ended up looking like.
    [​IMG]
    [​IMG]
    /forums/images/icons/tongue.gif
     
  13. BobK

    BobK 1/2 ton status

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    Re: Are you supposed to \"bleed\" a new stack plate tranny cooler?

    pic's up now.
     

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