Thread: How to: '00-'03 Grand Prix standalone transmission fluid cooler

There is not one way to do it , but there is one way for each person - says unknown

Using barbed fittings and hose clamps isn't the worst thing in the world. Just make sure you got good hose clamps.

I think problems occur when people try to clamp rubber line directly to the smooth steel line, and it spits it right off.

Well that's just stupid

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And yet people still do it ! (That's what I was referring to)

Originally Posted by JamesIvey24

I wouldn't put anything or disturb anything in between the trans and the radiator line, as that is somewhat of a pressure line and I've seen and heard many issues, leaks, lines popping off, etc...and that goes for more than just these 3800 powered cars. Personally I wouldn't ever put a trans cooler in these cars, however...if a person would choose too, it's safer to insert it after the radiator, before the return side of the trans.

Sorry but that is just ignorant. The GXPs bassically need a trans cooler to survive under abuse in stock form and anyone making any kind of power with an aftermarket torque converter needs one. I didn't have one of my Billet 3000 stall and the trans jumped to 260 in one pull. If done properly with hoseclamps and the right size barbs it will not leak.

Originally Posted by JamesIvey24

Personally I wouldn't ever put a trans cooler in these cars,

Why not?

Originally Posted by JamesIvey24

as that is somewhat of a pressure line and I've seen and heard many issues, leaks, lines popping off, etc...and that goes for more than just these 3800 powered cars.

Originally Posted by Bronco Boy

Why not?

Originally Posted by HighOctaneRacing

He gave his reasons lol

Just because a bunch of people did improper installs is not a valid reason to me. Thought there might be more to it.

Originally Posted by ADecker

I ran the hot fluid into the cooler, then into the stock cooler then into the trans

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From what I've read, that's backwards. You are reheating the fluid at that point. It should go Trans->stock cooler->external cooler->Trans. That way the coolest fluid goes back into the transmission.

This is a super clean install though. If I lived back in a warmer climate I'd do this. I still might do this, only add in a thermostat...

That's the point. You want the fluid at around 180-190, the trans cooler will cool it a ton then the stock cooler will get it back to operating temp. Especially smart in cold states. Otherwise your running cold cold cold fluid forever

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I always went off of 175*F being the max I've hit 180*F once or twice. That's why I'm gonna go the thermostat route, nothing will go to either cooler until it gets to temperature.

Uhm... What? The trans doesn't have a Tstat? It's always pumping and cooling fluid.....

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You can add a thermostat to the cooling lines. I read about it over on FSB where guys have good luck with them. Not this exact one, but something of the sort:

http://derale.com/products/fluid-coo...-chrome-detail

God no! Then you dont have fluid flow back to the transmission! Why make this complicated and mess with flow, go cooler then radiator. Problem solved. Unless your somewhere where its always hot, then just run the cooler



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I see now it doesn't totally stop flow but still that would make me so nervous and is pointless

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The thermostat I'm talking about just loops it back into the transmission until it reaches temperature then it goes onto the coolers. I'm wanting to try it out just to see how it works, and for a few other reasons. I monitor everything very closely so we'll see what happens. I might have the thermostat put in between the radiator's cooler and the external cooler. That way it's always got at SOMETHING if the thermostat fails.

Edit: I didn't see the second post. If I could find somewhere to mount it, there are oil filter adapters that have thermostats built in. I was hoping to find somewhere to put it, I dunno. Then I'd have the thermostat, external filter, and the cooler.

You have no way to monitor line pressure .... so if that thing doesn't allow enough fluid back good luck with the rebuild. The transmission fluid is the life blood.

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By pass valve to aux cooler

I don't mind rebuilding it. I've been planning it for awhile. These are designed for this use so I don't see it being a problem. Hayden has one like the one linked, but I'm thinking I'll start looking for a place to mount one that has a oil filter and a thermostat...once I find one, lol.