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Trans cooler - Bypass radiator?

Discussion in 'The Garage' started by AZ_Overdrive, May 25, 2005.

  1. AZ_Overdrive

    AZ_Overdrive 1/2 ton status

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    Hi, just another quickie,

    I have been running a fan assisted trans cooler for about a year now on the 89' Burb with the "recommended" setup (keep trans cooler lines going thru radiator then cooler and back to trans) but I now have questions....


    I understand, and have read many posts about keeping the trans hooked up to the radiator for initial warmup but I am assuming that that brass cylinder in the radiator (built-in trans cooler/warmer) doesn't cool anything when the engine is up to full temp.

    Quandry:
    If I am trying to keep the trans temp as close to 160 as possible (also have a temp gague on the return line) and the engine is running at a consistent 190 -220 why would I want to have the trans cooler lines running thru the radiator?

    This is important to me as I am an Arizona guy and with temps cracking 113 cooling is a HIGH priority.

    FYI:
    I also added a Deralli trans pan with cooling tubes.

    Thanks for any assistance.
     
  2. loafer

    loafer 1/2 ton status

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    The argument for keeping the factory radiator cooler is that the radiator temperature is usually significantly lower than the trans. fluid coming from the trany. and because the brass heat exchanger in the radiator provides better heat transfer because it is immersed in coolant; coolant is much better at removing heat than air. The radiator heat exchanger will never add heat unless you have an engine cooling issue.

    You can run w/o the factory cooler, but make sure the trany cooler you are using is large enough and you monitor the temperature of the trany.
     
  3. AZ_Overdrive

    AZ_Overdrive 1/2 ton status

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    Thanks Loafer. I remember the argument (water vs air). I think if I get an answer to my clutch fan with spacer question I will be all set without messing with bypassing the rad tank for trans.

    Thanks!
     
  4. ntsqd

    ntsqd 1/2 ton status

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    FWIW On my Sub I run an 11"x11" stacked plate cooler b4 routing thru the radiator cooler. I know this works the fluid harder, but it is a consumable. I don't think of the trans that way.
    700R4.com told a friend of mine when he bought a trans from them to monitor trans fluid temp in the pan and that they don't want to see more than 150*f there.

    While the heat exchange btwn the coolant and the trans fluid may be more efficient than the coolant to air exchange, dumping the heat into the air still has to happen. So instead of one inefficient heat exchange you've got one marginally efficient exchange and one inefficient exchange. I don't see a huge cooling advantage in that. For cold country I would REALLY hesitate to take the radiator cooler out of the system for the reason mentioned in a previous post. It is the reason mine is still plumbed in the system, I want to be able to take the Sub anywhere.

    The downside of using the radiator's cooler, particularly in hot country, is that the heat dumped by the trans fluid is heating the 'cool' coolant about to be pulled into the engine. If the situation, be it the result of mechanical problems or simply high ambient temps, is on the ragged edge of maintaining an acceptable coolant temp this could put it over the top and result in overheating.

    Given your location, if the cooling system is sound and you're still having overheating issues I would not hesitate to remove the rad cooler from the trans cooling system. Just keep an eye on the trans temps and don't be afraid to add a second or even third trans cooler if need be.
     
  5. AZ_Overdrive

    AZ_Overdrive 1/2 ton status

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    ntsqd,
    Good points indeed! That was kind of my original thinking. Since installing the trans temp gague (sender is just after trans fluid exits the cooler) I always have my eye on it and the engine temp.

    When the weather is cool, the trans stays nice and cool (160 or slightly below) unless I am giving it gas or stop and go but it does cool back down quickly. It's during the killer summers here in AZ that have me concerned.

    I may just experiment with bypassing the radiator but set it up in a way that would allow me to switch back and forth (no cutting of tubing) and see what works better.

    I need to switch to a different trans cooler as well since I am using an "S" tube type with an electric fan on it. Need to use a plate type instead.

    Thanks for the info... I hope someone answeres my clutch fan question (different post)!
     
  6. HarryH3

    HarryH3 1 ton status Author

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  7. sweetk30

    sweetk30 professional hooker Premium Member

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  8. AZ_Overdrive

    AZ_Overdrive 1/2 ton status

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    BTW... The Deralli trans pan with the cooling tubes works pretty well on the freeway/highway (speeds above 55). Here in AZ yesterday I was heading down the freeway at around 65 after some stop and go traffic that brought the trans temp close to 220 and after about a minute or two on the free way the temps dropped down to 160 and stayed there. Ambient temp was around 110.

    Of couse, once I left the freeway the temps went back up. Before I installed the pan the temps would go down in a similar situation but not nearly as much or as fast.
     
  9. ntsqd

    ntsqd 1/2 ton status

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    I would guess one of those would be particularly helpful in a vehicle that sees both extremes. Could put enough cooler for hot weather w/o worrying about it in cold weather. BAT-Mocal and Baker Precision also carry them.
     
  10. highrlr

    highrlr 1/2 ton status

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    I am looking for a new trans pan, Do they have a website?
     
  11. AZ_Overdrive

    AZ_Overdrive 1/2 ton status

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  12. mrhoes

    mrhoes 1/2 ton status

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    I ditched the factory cooler and turned the ac condenser in a cooler, and has worked great for me and I am not very nice to the tranny mud etc. , Im in Texas and it gets hot here so in Arizona its even hotter. just my opinion :D
     

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