Hey there. I have searched but can not seem to find a straight answer. which line to I add the cooler to? It has a cooler in the rad now but I am planning a 2800 mile trip starting Friday and I want to add a cooler before I head out. I don't have a book on it yet and so far I have been getting conflicting info. The local transmission place said to hook into the return line. which he said would be the line at the rear of the trans. I think it is a 727 trans 318 engine. but while looking for fittings etc. a performance site said for the torqueflight tranny you feed the cooler with the front line from the transmission. (this makes more sense to me). I do not want to by pass the cooler in the tranny I want to use both.
97B2500CCV
07-11-2009, 08:41 AM
It is good to use both. Now for summer application I would use the the line that goes to the rear of the tranny to hook the external cooler after the radiator cooler. For winter where you live I would reverse that and run the external cooler first then the radiator that way the trans does not get too cold in the winter time.
alloro
07-11-2009, 12:41 PM
I would use the front line. Here are my reasons:
1. The fluid is cooled before entering the radiator. This helps prevents the heat from the tranny from reducing the ability of the radiator to keep the engine cool on hot summer days.
2. In the winter, the tranny relies on the fluid being warmed up by the radiator. If the cooler was in the return line, then the fluid returning to the tranny would be cooled by the cooler, which is just as bad for a tranny as too much heat is.
1275gtsport
07-11-2009, 10:01 PM
I would use the front line. Here are my reasons:
1. The fluid is cooled before entering the radiator. This helps prevents the heat from the tranny from reducing the ability of the radiator to keep the engine cool on hot summer days.
2. In the winter, the tranny relies on the fluid being warmed up by the radiator. If the cooler was in the return line, then the fluid returning to the tranny would be cooled by the cooler, which is just as bad for a tranny as too much heat is.
this is a motor home chassis so it is not used in the winter.
I had the same thought that if I cooled the fluid running into the rad it would help lower the overall temp. but what is the general temp of the tranny? and if the additional cooler lowers that temp lower then the temp is in the bottom of the rad isn't just going to get heated back up to the temp it was before the cooler had been added?
So seeing as the goal here is to keep the transmission from over heating, I agree that the return line is the place to put it. for summer use.
B-300
07-13-2009, 01:35 AM
I would use the front line to the cooler as this is were the fluid is the hottest, especially in a motor home pulling hills in the summer the torque converter produces a lot of heat and can heat the fluid to over 220*F easy while the engine runs at less than this temp (180-190). A transmission cooler of reasonable size will do a better job at cooling than the radiator cooler will do at warming the fluid because it will have several the ability to remove heat due to it's size.
chigato
08-31-2009, 03:57 PM
Stay out of the radiator all together. I 've seen a few radiators contaminate the tranny,( usually was a GM).... Front tranny line to the top of the cooler, bottom line of cooler out to the rear( return) tranny cooler line. My 2 cents.
pittwagen
08-31-2009, 11:46 PM
I had a 74 Dodge B200/360/727 motorhome many years back and I decided to install a Hayden trans cooler. Hooked into the front/pressure line, through the external cooler then back to the rad cooler and it worked really well. I believe this method was recommended by Hayden.
We used to pull some really steep mountain passes. Never a cooling issue even on the hottest days. Used to get dam hot in the van though without a/c.
Now on the gas front, we never passed many stations with the small tank so we got lots of breaks.
