The Stovebolt Site Forums The Shop Area The HiPo Shop Transmission cooler

I have two questions concerning my 1957 3600 which has a 350 engine and 700r4 transmission. PO installed an aftermarket trans cooler and kept the stock radiator. I have installed a new radiator which includes a trans cooler. Is there a benefit to plumbing the radiator cooler inline with the aftermarket cooler or should I leave as is? Also, the trans cooler lines are braided hose, which I have never seen used in this application. Should these be replaced with hard lines?

As far as the trans cooler, it depends on your use case. A lot of the trucks that came with 700R4 and 4L60e transmissions got an auxiliary trans cooler with the towing package. A 3600 is probably heavy enough that it would not be a bad idea to keep both.

There are braided lines that are designed for transmissions. They are fairly commonly used in aftermarket conversions so chances good that you are fine. If you want to replace them with hardlines, that would certainly work as well.

Make sure they can't touch anything, the braid is a low-speed hacksaw.

I had a tech at PATC tell me that the radiator trans cooler dissipates heat 3X faster than an external cooler. Trans fluid also flows best between 175 and 225. With that said there's no reason not to use the radiator trans cooler. If you're towing or you live somewhere hilly, an external cooler isn't going to hurt anything.

An oil-to-coolant cooler is WAY more efficient than an oil-to-air cooler. Just engineering basics says that. You could plumb both coolers in series, which would be a little more insurance that your tranny doesn't overheat.

In the same conversation the PATC tech told me that if I was going to use an air-oil trans cooler, buy the biggest one you can find.

Since we don't get much extremely cold weather in our neighborhood, using the radiator cooler and the auxiliary in tandem isn't a problem. In the far north frozen wastelands (anywhere north of Kentucky) it's possible to over-cool the trans fluid in the winter.
Jerry

Thanks to everyone for their input. It looks like I'll be connecting both coolers and I may just leave the braided lines in place.

oldbolter Learned on a turboed heavy gooseneck truck that we sent across 2 states...that it was when you backed up that those cooler lines payed. Went to back up hill to a dock,it blew tranny fluid 30 feet out in front of the truck, Happened right at home out in our lot,then put on hard lines.

Oldbolter, my setup is similar to yours, 59 TF with 350 with 700R4. I originally set it up with a B&M supercooler, no radiator cooler. I could not keep the transmission fluid below 230 on a trip. I added a Deraille 'hyper cooler' in series with the B&M cooler and my transmission fluid never gets over 200. The Deraille cooler has a fan that is set to come on whenever the fluid temperature leaving the transmission is over 185 degrees. I just completed a road trip through many mountain areas pulling my small camper and the Deraille cooler always kept the temperature below 200. Of course your benefit of using the radiator cooler is that your warm coolant will help keep the transmission fluid warm in cold weather.

Mark

Thanks for the input.

Good point, I will add to my spare parts list. Do you have an idea what is the typical hours to failure for the cooler fan? This may be just something that needs to be regular scheduled maintenance replacement. I have only been running the Deraille cooler for less than 10000 miles

Mark

A fan that only runs "on demand" whem the fluid temp is high should outlive its owner, unless you're pulling a 24 foot goose neck trailer all the time. While you're at it, lose a little sleep worrying about about why the kitchen faucet isn't dripping!
Jerry

Typical mistakes people make with electric fans, not enough CFM for the application, not a large enough gauge wire for the amp draw. In all the years I've been working on the fleet, on all kinds of weird equipment from A to Z, I haven't seen an electric fan fail yet.