Since we were discussing transmission coolers

Yes, Hayden is one of the best IMHO. Can't say 'yea or neigh' on the rapid-cools, I've always used the regular style (biggest model, made for Class A motorhomes towing up to 10,000#) with great results.

On my current truck, on a 90* day, A/C cranked, mountainous roads with long inclines, cooler feed-line temps went from 200-210* to 140-150*.

Doc

Reason I thought about the rapid cools is my truck is an s10 so I have less space to work with. I hit 230 driving home on spring days, haven't even hit a 90 day with the ac running yet.

On my 89 S-10, I had persistent heating problems. It finally got so bad one time that the transmission boiled and blew fluid out of the vent. After that, I aggressively started working to cool the truck down.

First I installed a transmission cooler. I used whatever Pep Boys was selling that fit into my truck. No special rapid cool, etc.

Next I repalced the 195* thermostat with 180*. I used to swap them winter and summer, but then I just left the 180 in all the time. Its ok, and I only lost 1 MPG.

Finally, I replaced the radiator. THe OEM radiator looked ok, and it wasn't leaking, but the Modine I installed made quite a difference. I guess a few of the little channels were blocked, and with a radiator that small trying to cool the 4.3 liter, there was no room for error.

After replacing those parts, I haven't had any problems in

Jeff