A/C condenser and transmission cooler - questions

[71CHEVYSHORTBED402]

71 C/10: This truck has the original (edit: see post 4) external transmission cooler mounted to the core & hood latch supports. I don't care for how it was mounted, primarily because it interferes with the LH park light connect on the core support. If I use this cooler, then I'd like to raise it and/or pull it forward.

This truck had A/C and will again. The condenser isn't mounted. As of this moment, I don't know how it's mounted. ........So, my questions are:

1. Do you recommend replacing the transmission cooler?

2. If so, can you recommend a cooler with hardware that mounts nicely to the support(s) and clears the condenser?

3. Can I trouble someone to take an image of the top of the original condenser, so I can see where it mounts and judge how much room is left for a cooler?................. If you can provide images for how it's mounted that's bonus and appreciated, but not necessary.

4. And my dumbest question of all, beings I'm taking a cooler off, do you recommend using a coupler to join the two hoses attached to the cooler, for temporary? Maybe caps instead? I can't imagine there would be a problem, but green prefers to ask a foolish question than jack something up.

I know many of you recommend using the radiator, but I likely won't. Don't know what's involved, which probably isn't much, but I assume to stick with the external only. The trans. has gone this far (45 yrs, 140K), still shifts like new and I won't be towing anyway.

Any other recommendations appreciated. Thank you


Image of current:

[picklito]

I'm setting up a trans cooler on my 70 big block. Went to Pick-n-Pull and got a stock cooler from a more recent model 2500. Pretty much every 'burb and truck in the row had one. Got the hard lines, too. The only "mod" I did to get it to fit was to flip the bracket around relative to the cooler, so that the bracket gives a little more stand-off distance so the cooler clears the condenser better.

You don't "have to" use the internal/radiator cooler, but I like to. It does help keep the trans from running too cold. I run them in series.

Generally you shouldn't cap the cooler lines. I'd connect them together and let the fluid flow around the loop, even without a cooler until you get one.

[71CHEVYSHORTBED402]

Thanks for the suggestion for a coupler. Yeah, seems employing the radiator is a favorite. From what little I've read, the downfall is coolant leaking into the trans. Probably unlikely, I suppose.

Just found an image of a condenser. Looks like it takes up the entire width of the opening for the radiator, on the core support. Must have been a real tight fit on this truck. The cooler needs to come out IMO, at least an 1" on the LH truck side, and maybe higher too. Correct me if I'm wrong, but I believe the holes on each corner of that opening on the core support are for the condenser. Think I'll mount my reject condenser, see what happens. I'M SUPPOSED TO BE REMOVING PARTS, NOT ADDING THEM........ha!

On a side note, I've found the most challenging part of this project are things that aren't factory correct, as I'm removing parts. Bits and pieces.

[leddzepp]

I'm not aware of an OEM external (auxiliary) transmission cooler My 72 is original and the lines run through the heat exchanger on the radiator. It runs at operating temp. with no issues even in the summer months with AC blowing. There is nothing wrong at all with adding an external cooler, as it certainly helps keep temp down, especially if you are towing or hauling a heavy load... but I don't think it was OEM. Your 71 originally had lines running through the radiator.

[71CHEVYSHORTBED402]

Originally Posted by leddzepp

I'm not aware of an OEM external (auxiliary) transmission cooler My 72 is original and the lines run through the heat exchanger on the radiator. It runs at operating temp. with no issues even in the summer months with AC blowing. There is nothing wrong at all with adding an external cooler, as it certainly helps keep temp down, especially if you are towing or hauling a heavy load... but I don't think it was OEM. Your 71 originally had lines running through the radiator.

It was likely an add on. I've only owned this since 89. One previous owner. Hmmmm, interesting thought though. Now I'm thinking to do away with the external. After all, I would like to go original. Much involved in the conversion? I need a new radiator anyway. It's the wrong one, and they destroyed the fan shroud in the process.

[leddzepp]

You would need an OEM shroud and hard lines along with a replacement radiator. Does it have the OEM fan/clutch assembly?

[Andy4639]

This is my AC setup. The condenser takes up as much room as the radiator almost. My aux trans cooler is behind it. You can see the hoses going to it.
The opening on top I closed off with foam to force the air through the coils.

[71CHEVYSHORTBED402]

Originally Posted by leddzepp

You would need an OEM shroud and hard lines along with a replacement radiator. Does it have the OEM fan/clutch assembly?

Yes, I have a correct shroud and restored clutch fan. Note: The "hard lines" may still be in this truck............The rubber hoses for the auxiliary cooler are clamped onto them near the battery. What else would I need? You mentioned a heat exchange. Where approx. does that mount?

Once again you've talked me into going another route. Goodbye auxiliary cooler. Thanks Zep.

[cleszkie]

If you are not going to be really taxing your tranny by towing, I would just use the heat exchanger in the radiator as others have recommended. The engineers at GM knew what they were doing and designed it to perform.

Another thing to consider when stacking a tranny cooler with your A/C condenser is that it will decrease flow through the condenser and add radiant heat to it. These two things will ultimately decrease the efficiency of your condenser and result in slightly warmer air at the vents in your cab.

Lastly, if you absolutely feel you need an additional oil cooler of some sort, there are the long copper tube coolers with radial fins that you can replace sections of your existing hard lines with. They will not be located in front of your radiator, but would be exposed to air flow under the truck. The fins act as heat sinks and cool the ATF as it runs through. You would run this type of oil cooler in line with the heat exchanger in the radiator. I have seen this done on many trucks.

[71CHEVYSHORTBED402]

Thanks......No, I decided the aux. has to go. I'll "convert" back to where it's supposed to be.........Sweet Blazer, BTW

[MikeB]

Here's how I did the aux trans cooler in my 69 C10. It's off to the side of the condenser.





When it comes to AC condensers, the bigger the better. I like the Super Flow models sold by Vintage Air.

[truckster]

Originally Posted by 71CHEVYSHORTBED402

From what little I've read, the downfall is coolant leaking into the trans.

In 40 years of working on cars, I've never seen it. That doesn't mean it never happens, but I think the chances are extremely slim.

[Andy4639]

Originally Posted by truckster

In 40 years of working on cars, I've never seen it. That doesn't mean it never happens, but I think the chances are extremely slim.

I second that! If you take care of the vehicle and keep the fluid changed and up to the correct levels it's a good chance you will never have this happen. I have never had a transmission fail due to water getting in from the radiator.

[picklito]

Me neither. To me, it's like saying you wouldn't put coolant in the engine because it could leak into the cylinders. Well, yes, it could...

...Actually, I hear of that happening a lot more than coolant in the atf!

[71CHEVYSHORTBED402]

Okay, I give. Maybe I'm missing it, but combing through my manuals came up empty. Other than a radiator, can anyone provide a link or advise what's required for the original trans. cool set-up? A link to how it's assembled would be a bonus, but I haven't given up on the assembly manual yet. Thank you.

Edit: Think I found something...Then again, by chance is it just a radiator? What the?: http://image.carcraft.com/f/9167884/...er+diagram.jpg

[picklito]

That diagram is how I've always done mine and they work well.

[71CHEVYSHORTBED402]

Is that diagram for an auxiliary as well? Snap!, I think I've made a mountain of a mole hill. Correct me if I'm wrong, but without an auxiliary, the lines plug into the radiator and you're done. Just have to have the right radiator. In fact, possibly most are the right radiator. The one I have has two plugs under the cap side.....Go figure, right near the lines from the trans. I'm pretty green man............sometimes slow too...............When it's all said and done though, I figure to know this truck pretty well.

If I'm on the right track, I'm curious, how much pressure/fluid is in those lines? For example, if you were to replace the radiator say, would you cap the lines, or maybe drain the transmission fluid first?

[Rannoch]

Originally Posted by 71CHEVYSHORTBED402

Okay, I give. Maybe I'm missing it, but combing through my manuals came up empty. Other than a radiator, can anyone provide a link or advise what's required for the original trans. cool set-up? A link to how it's assembled would be a bonus, but I haven't given up on the assembly manual yet. Thank you.

Edit: Think I found something...Then again, by chance is it just a radiator? What the?: http://image.carcraft.com/f/9167884/...er+diagram.jpg

The original setup had the hardlines going into the radiator.
They used some kind of flared connection.

No external cooler at all.

[71CHEVYSHORTBED402]

Originally Posted by Rannoch

The original setup had the hardlines going into the radiator.
They used some kind of flared connection.

No external cooler at all.

Bingo....Thanks. That's pretty simple. I would say my lines are a little distorted and need replacing. Won't know for certain until I'm ready to put the truck to sleep. Lots to do before that happens. Thanks for all the information. Sending that aux. to the dump. Not that they're not a bonus. Just figure not to need one, and it's one less thing to worry about. Really, thanks for the info.

[picklito]

I bought a cheap pliers-looking tubing bender, and just worked along their length a little bit at a time. They came back into shape pretty nicely. They run right along the oil pan rail just as original.

[71CHEVYSHORTBED402]

Originally Posted by picklito

I bought a cheap pliers-looking tubing bender, and just worked along their length a little bit at a time. They came back into shape pretty nicely. They run right along the oil pan rail just as original.

I think it's time to score one, thanks. I believe they're just distorted where they connect. Couldn't tell you what motivated someone to set it up this way. From what I've read, they only made it worse.

[picklito]

Mine were badly bent up... and... why? Ha Ha.

[71CHEVYSHORTBED402]

Originally Posted by picklito

Mine were badly bent up... and... why? Ha Ha.

Exactly

[picklito]

This worked fine: http://www.summitracing.com/parts/sum-900675
I also bought a flaring tool cuz I plan to make my own hard lines to extend to the aux cooler. Not a fan of rubber hose!