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Trans Cooler Question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by 78pileofparts, Jan 27, 2003.

  1. 78pileofparts

    78pileofparts Registered Member

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    I've got a trans cooler that I want to install on my '78 K10 with a TH350. I wanted to get a sanity check on the installation since I lost the instructions. I'm assuming that the upper line off the tranny flows towards the radiator while the lower line flows back towards the tranny. Is this correct? Does it matter if the trans fluid goes through the radiator before it goes through the auxilliary cooler? My plan was to run the upper line to the upper fitting on the radiator, lower radiator fitting to the upper auxilliary cooler fitting, lower cooler fitting to the lower tranny line. Does this sound right?
    Thanks!
     
  2. heavy4x4

    heavy4x4 1/2 ton status

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    Upper line off the radiator flows BACK to the tranny. Lower line is the inlet. I know...sounds backwards.

    The way you have it described, the fluid will first flow through the aux cooler and then into the radiator. That's not the recommended method by manufacturers, but it will be ok. You'll still get approximately the same amount of cooling, it's just that the manufacturers would rather see some cooler fluid run through the rubber lines and unit instead of the stuff straight from the tranny. I have mine set up so that the aux cooler is plumbed into the top/return port on the radiator.
    Hope that helps you out.
     
  3. BigRed89

    BigRed89 1/2 ton status

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  4. Sandman

    Sandman 3/4 ton status Author

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    There are different schools of thought on this. I used to have troubles with the tranny overheating the motor through the radiator. I put the external cooler first and then ran it through the radiator. That fixed the engine overheating but the tranny still got hot. I bypassed the radiator altogether and that fixed everything. the radiator was actually warming the tranny fluid up and giving the tranny like 180 degree fluid. Now it gets cooler stuff and does not heat up so bad. I am on the extreme side some and you may not experience the same problems.
     
  5. big pappa b

    big pappa b 3/4 ton status

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    I'm with Sandman on this one. Don't even bother with going thru the radiator, just use the trans cooler
     
  6. imiceman44

    imiceman44 1 ton status

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    I did the same as you sandman, but it is not the only way, actually if you are in colder climates you want the tranny fluid to warm up a little, but not to 180.
    140-160 is ideal for a tranny and 180-190 is ideal for engine, so I am trying to figure out a way to have a hook up through the radiator with a bypass when the tranny fluid is 140 I bypass it. Still working out the details.
    The important thing is to have a tranny temp guage.
     
  7. Sandman

    Sandman 3/4 ton status Author

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    You live in a cold climate? I've never had any issues with having the tranny too cold. I think that in a less extreme situation it would be fine to pipe it through the radiator and not have any worries. My tranny heats up no matter what the temp is outside.
     
  8. imiceman44

    imiceman44 1 ton status

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    I live in Sac so no it's not cold, but I go on snow wheeling and stick around freezing temps, so I am looking at a way I can have both.
    I just like to invent, why not his. /forums/images/graemlins/thumb.gif
    I agree I have been driving it for a few months like this and so far it's been fine, and I did go snow wheeling but I drove up there and then wheeled it and drove back so it didn't sit in the snow.
     

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