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

Here's how I added a standalone transmission cooler to my '00 Grand Prix. From what I understand, some '99s, and all '00 thru early '04's are unique in that they have an "external" check valve in the cooler feed fitting. So we are required to use this check-ball fitting in anything we do. So here's what I did based on a couple criteria:

1.) It had to work. If it didn't keep the fluid cooler, or it leaked, it was pointless.
2.) It had to look good. No hack job. I'm a professional.... Kinda.
3.) No hose clamps, because... See 1 and 2.
4.) I had to be able to revert back to stock fairly easily. I bought some extra cooler lines at the junkyard to hack up, and my original lines are sitting on a shelf.

Here's a complete parts list;

Hardware:
6- 1/4"-20x3/4" Bolts
2- 1/4"-20x1" Bolts
5- 1/4" Flat washer
8- 1/4"-20 Lock nut

Support:
1/16"x3/4"x36" Weld steel Local hardware store / Steel supply house

Cooler:
B&M Super Cooler # 70266 http://www.summitracing.com/parts/BMM-70266

Lines:
1- -6an x 3' ready made hose* http://www.jegs.com/i/JEGS-Performan...10613/10002/-1
1- -6an x 4' ready made hose* http://www.jegs.com/i/JEGS-Performan...10614/10002/-1

Fittings:
1- -6an x 1/2" NPT 90° http://www.jegs.com/i/JEGS-Performan...10159/10002/-1
1- -6an x 1/2" NPT http://www.jegs.com/i/JEGS-Performan...10119/10002/-1
2- -6an x 3/8" NPT http://www.jegs.com/i/JEGS+Performan...10106/10002/-1
2- 3/8" Tube (Compression) x 3/8" FIP 90° Hardware store / Plumbing supply house
2- 3/8" NPT plugs (to plug old cooler holes in radiator)

I chose to splice into the factory lines where I did, because I wanted to retain the factory cooler line support on the transmission. I didn't want the weight of the cooler line hanging off that quick disconnect fitting. The only thing not shown here is the pipe plugs in the radiator to block off the old cooler.

Everything laid out. An "exploded" view:


Here's the cooler mounted to the radiator support:






The clearance required for the support in the left air inlet duct:




The clearance required for the upper elbow in the air baffle:






The clearance required for the hoses in the radiator support:




The clearance required for the hoses in the air baffle:




Compression fittings in a different location than shown in the layout view.
Assembled view from top:


Assembled view from bottom:


Standard 3/8" NPT brass pipe plugs


Installed


*After getting everything assembled, I ended up with about a foot extra on each hose. Knowing what I know now, I would order a 2' and 3' ready made hose. The little difference from the custom cut length wouldn't be a problem. The lengths of the hose reflect the feed line supplying the bottom of the cooler and the return line coming from the top. This ensures no air in the cooler.
Leftover hose


Random pictures:
Teardown


Check ball "feed/supply" fitting


3/8" Tube to -6an fitting


Cooler hose laid out


Cooler view looking up


Assembled




I won't know for sure how much of a difference this makes for a while, but I have to image it can only help out here in the southwest.

Awesome. Just in time for me to throw one in. Thanks!

Amazing write-up - really good photos. I know I'm in a Regal but I'm looking for something like this on mine.

Any numbers on temps before and after?

Thanks guys. If there's any questions, or you need a better look at anything in particular, let me know. I didn't do a ton of writing. I figured I'd let the pictures do most of the talking.

Something else I should mention; I'm not sure what the ramifications of running a standalone cooler in a colder climate are. I live in Tucson. It rarely, if ever, gets below freezing here. I was fairly certain it wouldn't be an issue for me.

As far as temps go... Not much yet. Only one short trip. While the engine was at 190°, the trans temp held at 150°. Before they would be pretty much identical. Maybe an extra 10° for the trans. I'll know for sure when the heat of summer hits, you know, when it's 120° in the shade!

Last year we took a drive up the mountain, and I got stuck in a line of slow moving cars. I can't remember the exact number, but I want to say I was hitting over 250°. I'm really curious to see what it would be now.

I'll post some numbers once I get in some stop and go, summer traffic.

Great write up. I have been thinking about doing this when I install my rebuilt transmission. I live in Peoria AZ and am also curious how much of a difference running only an external cooler will make. What intake are you running. Looks good!

Originally Posted by buford1972

What intake are you running. Looks good!

Thanks. It's custom;
http://www.grandprixforums.net/threa...derwell-intake

Took the wife out for lunch today. Got some pretty solid numbers for city driving.

Ambient temp - 115°
IAT temp - 120°
Engine temp - 210°
Trans temp - 185°

These are the peak numbers I saw during my 40 minute drive with the AC running.

Originally Posted by GotMelon

is it like an AN fitting, were you have the nut on the line, stick part of the fitting inside the line, then tight the nut down and it seals?

Basically, yes. You have the female side of the fitting, a ferrule, and a nut. Slide the hard line through the nut, and ferrule into the fitting. When you tighten the nut, it forces the ferrule to compress on the line.

I did see those. I wish they came in a 90°. I would have been all over them. Handy little fitting, for sure.

Lol. I did mine the lazy man's way! Cut rubber parts of stock lines, splice in with standard barbed fittings, mount cooler, done.

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So curious, what lines did you run where? Sorry i read your write up but may have missed that. I am installing one in about 6 hours and has to be done before i go to work. i do not have the AN fittings, just rubber hose and barbed fittings like Adecker. Just want to make sure i run them the correct way. Thanks for any help

Originally Posted by ADecker

Lol. I did mine the lazy man's way! Cut rubber parts of stock lines, splice in with standard barbed fittings, mount cooler, done.

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What lines did you run to what? thanks for any advice. Doing mine the same way for now

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

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You don't have to cut any lines if you buy the propped fittings. Trying to flare the steel trans line is 50/50

You don't have to flare either... There is a rubber part of the line in the middle of the lines. Cut them. Use std fittings from the hardware store. sleep well

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