Radiator / Tranny line Q

[86 Waggy]

Hello, I'm completely new to tranny cooling and have a few questions. I just got the aluminum radiator / tranny cooler with electric fan. I have a late model heavy duty 700R4 auto transmission.

Where do the lines connnect on the transmission, and does it matter which way I configure the lines into the transmission from the radiator (e.g. top and bottom lines)?

What size are the lines and fittings? What type of line should I be using, stock cooling lines won't fit, so I am assuming I'll need flexible steel lines, no one around here seems to carry anything, any ideas where I can get lines and fittings?

Is there a specific fluid I should be using when I cool the tranny? Is the tranny cooler a sperate closed system inside the radiator?

thanks for any help.

[Ryan]

On the 700R4, the bottom fitting on the right is the "out" line to the cooler and the top fitting is for the return line from the cooler. Lines are, as I recall, 3/8". From the trans forward, I usually use hard-lines that I bend, or sometimes I'll use braided flex lines. If braided flex lines, you can run those all the way up to the cooler. If hard-lines, you can run them up front, then use a rubber line and clamps to allow for flex, then connect the other end to brass fittings on the cooler.

Also, on aluminum radiators, NEVER use teflon tape, ALWAYS use teflon paste. The tape can bind up and ruin the threads.

For the fluid, regular ATF is barely adequate, but there are better fluids out there if you do some searching. For the cooler, if you are talking about our Crossflow radiator, the internal cooler is a separate system build into the radiator (ie: the fluids never mix).

[86 Waggy]

Tks for the reply do you know what size fittings I need to buy for the radiator.

the radiator looks like it was all connected with the trans cooler which left me baffled tks for clearing that up.

[Ryan]

I believe they are 1/4" NPT fittings. On the radiator / cooler, the aluminum crossflows we sell have a built-in trans cooler that is internal to the radiator, but you can also run that in series with an external cooler. You always want the "out" port on the transmission to go to the upper port on the radiator trans cooler, and then the lower port on the radiator trans cooler to the upper port on the external trans cooler, then the lower port on the external trans cooler back to the "in" port on the transmission. If you are only running one cooler, just eliminate the loop on whichever you don't want to use.

[Brent]

Ryan got a little mixed up on the routing....

You want to go from the transmission to the external cooler first, then back to the radiator cooler. The reason for doing this is your transmission fluid can get too cold on a cold day so running it through the radiator after the external cooler can warm it back up to operating temp. Even if you aren't in a super cold climate, this is still the recommended way.

[TheQueas]

also never seen a 700r4 with 3/8" fittings i suppose you could find fittings to screw in to the case that were but the internal passage's in the pump and case are the same size as the inside of the 5/16" line the size that the 700 came with

[86 Waggy]

Finally had the time to install everything, runs very cool now...almost too cool. I have a manual switch setup to turn the fan on and off right now...I rarely turn on the fan.

I was wondering if you sell a temp probe that will go into the fins of the radiator, as I do not have a hole in my manifold for the adapter the electric fan came with. If not does someone make one, sort of annoying to have to monitor the temp manually.

BTW the tranny fittings on the radiator are 1/4".

tks

[Brent]

We sell our radiator fan kits with either a 3/8" or a temp probe. They aren't listed on the webstore separately so give us a call and we'll set you up. Thanks!

[Rompn]

Just left you guys a voicemail at the shop. I have a 79' Cherokee with a Chevy 350/TH400 trans and your aluminum conversion radiator. Which is the inlet and outlet on this trans and which ones hook up where on the internal cooler on the radiator? Thanks.

[Ryan]

On the trans, the lower port is the line out to the cooler, and the upper port is the line in to the trans. On the radiator, I would pump the bottom trans port to the upper port on the cooler, and then the lower trans cooler port on the radiator back to the upper port on the trans.

[Rompn]

Thanks for the reply Ryan. I have an auxiliary cooler I'm also going to install at the same time so based on the reply a few posts up, the trans output should go to the aux cooler first and then to the radiator cooler, correct? If so, should the aux cooler be plumbed with the output of the trans going to the top inlet of the aux cooler or the bottom one? And then from there to the top inlet of the radiator cooler or the bottom inlet? Thanks again, I'm hoping to get this routed tomorrow.

[Ryan]

I would suggest going from trans to radiator cooler first, then to auxilliary cooler next, then back to trans

[Rompn]

I would suggest going from trans to radiator cooler first, then to auxilliary cooler next, then back to trans

Ok thanks Ryan. I confirmed this routing with a few others as well and am going to set it up this way. From what Brent was saying a few posts back he would go to the aux cooler first, then to the radiator cooler and back to the trans.