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radiator for auto trucks


djmoreron

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i just got a new radiator, but it has the two brass fittings for a transmission fluid cooler to be connected. do i need to plug these or can i just let it be?

 

 

btw, my truck has a manual transmission and the old radiator doesnt have fittings for the cooler.

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I don't really know anything about transmission coolers, but I'm assuming the oil just circulates through the radiator in order to be cooled, correct? I think it's the same case with the external coolers...

 

If that's the case you should be able to just leave it... if you're not hooking up your transmission, you're not going to be running fluid through it, and therefore don't need to worry about the plugs.

 

I would suggest just getting a garden hose and filling up the radiator. If it holds water and/or if the water comes out where it's supposed to, then you can leave it. If it comes out the fittings, then plug them.

 

Your old rad didn't have the fittings, but does the transmission? If it does then you may as well just hook it up.

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Manual transmissions don't use oil coolers. Automatic transmissions produce considerable amounts of heat from gear changes and the torque converter. They have an internal hydraulic pump so it's easy to send some of the fluid to, and through a cooler.

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I didn't think about that... I suppose when I swap over to an auto transmission I'll have to think about a cooler... Is it possible to just pick up any transmission cooler and fab up some lines to it, or does it have to be matched to the vehicle/transmission?

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I didn't think about that... I suppose when I swap over to an auto transmission I'll have to think about a cooler... Is it possible to just pick up any transmission cooler and fab up some lines to it, or does it have to be matched to the vehicle/transmission?

 

If you have ever cut a radiator apart and looked at the auto trans 'cooler' you'd laugh. Most are just a copper line inside that connects to the two fittings. Hardly looks like it would do anything, but it works.

 

I could only get a standard rad for my old '82 Dodge Omni, so I made a cooler from the condenser of an old air conditioner. It was an aluminum tube going back and forth with many aluminum fins. I connected it up with hoses and gear clamps and mounted in front of the rad and then drove from Ontario to BC. No problems. I'll bet mine cooled better than that little thing the factory made.

 

Ask any tranny shop. The worst enemy of an automatic transmission is HEAT. I would never run an automatic without an extra cooler mounted in line with the factory one.

 

Jason, the Nissan diesels do just that. The oil cooler is connected to the cooling system. Some Chevy blocks have an adapter that mounts under the oil filter, with two hard lines. All you have to do is get the air conditioner out of a mid '80s olds (or whatever) and get the evaporator out of it and hook it up. Don't forget that the oil is under a lot more pressure so hoses and gear clamps won't do.

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did the garden hose trick bout 5 minutes after posting this, no water leaked, so im good. :D

 

 

auto zone sold me a radiator with fittings for a tranny cooler and i got scared, but no water comes out, so it must be for the gear oil to pass thru.

 

yes, manual transmission = no tranny cooler. ive never taken apart a radiator, but maybe ill eff around with my leaking one. cant hurt... live and learn... thanks

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Mike: Mounting the transmission cooler in-line with the original rad is the way to do it, or can I mount it elsewhere providing I get enough airflow through it? If I'm at a stop light with it in park, will the fluid continue to heat up, or is this only during actual motion? I'm just not sure about the amount of room in front of the stock rad on the 521, so if I could get a small cooler and mount it down lower it might be a little easier...

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Here is one brand of add-on trans cooler:

http://www.hitches-forless.com/transmisson_coolers/transmission_coolers.htm I suspect even the smallest of these provides more cooling than the tiny one built into a Datsun radiator. I believe these are usually mounted in front of the lower face of the radiator, but you may be able to find instructions online. Also, I always thought the stock cooler in the radiator was bypassed when using an add-on one, but this is another thing to see what the mfg of the cooler says. I don't know how much pressure is involved in pumping the fluid to the cooler. Maybe enough you will need to use rubber hoses with threaded fittings from your hard lines to the cooler, not just hose clamps. You want to be sure about this as a leak under pressure will probably drain a trans pretty quick.

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Mike: Mounting the transmission cooler in-line with the original rad is the way to do it, or can I mount it elsewhere providing I get enough airflow through it? If I'm at a stop light with it in park, will the fluid continue to heat up, or is this only during actual motion? I'm just not sure about the amount of room in front of the stock rad on the 521, so if I could get a small cooler and mount it down lower it might be a little easier...

 

Either way hook up is fine I would do it in line with the stock one. The fluid will get hot at the lights but nothing like towing a trailer or being stuck in mud or higher speeds. On a hot day stuck in traffic it would get hotter if you have th air on but not dangeriously so. A tranny cooler is just good insurance and extends the tranny life.

 

 

I suspect even the smallest of these provides more cooling than the tiny one built into a Datsun radiator. I don't know how much pressure is involved in pumping the fluid to the cooler. Maybe enough you will need to use rubber hoses with threaded fittings from your hard lines to the cooler, not just hose clamps. You want to be sure about this as a leak under pressure will probably drain a trans pretty quick.

 

I think there is greater heat transfer inside the rad, as it is bathed in rad water which will conduct heat away much better than just air alone. This is why I would hook up the external cooler on the return line to the rad.

 

I did see an automatic once that had no cooling lines. It was for some foreign car. It had a tiny 4 cylinder and probably the tranny case would shed what little heat was produced.

 

Because the return line just dumps into the auto tranny oil pan there is no restriction so pressure does not build up. Oil resistant hoses will do.

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My mate runs the biggest tranny cooler he could find, with twin thermo fans, under the back where the spare wheel usually lives in his '85 Toyota Hilux. Not enough room between the radiator and the bumper/grill, he's running a 1JZ-GTE and also has to mount the heat exchanger for the water to air intercooler under the bed.

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Couldn't a person come up with a way to use that trans oil cooler built into the radiator to cool engine oil? Might be useful for a turbo setup?

 

I missed this one. Jason the auto cooler isn't under any pressure, ( or very little) hooking a 50 to 80 PSI oil line to it might rupture it. I'd go with an after market unit.

 

The SD25 has a tiny heat exchanger that bolts to the rear pass side of the block. Water enters from the block and exits through a hose and into the head. There is an entrance and exit for an oil line to exchange heat.

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