1989 Ford Club Wagon XLT | 351w | c6 | Gear Vendors Overdrive
I posted this question in the full size van portion and was told to post it here as well.

Long story short, I’m trying to rule out the radiator as being an issue. I believe my external OEM transmission cooler in front of the radiator is leaking.
Can i safely bypass the OEM External transmission cooler and still drive/run the van normally? I’m assuming it’s part of the tow package and it isn’t mandatory to run one.
Though if it is the issue, it will be replaced, as I do tow stuff regularly.

I've been in the process of replacing the radiator. I noticed that there was a small puddle of transmission fluid on the ground and the lower portion of the radiator looked as though the transmission cooling portion was leaking. I decided to replace it only to find out that I believe what's leaking is actually the transmission cooler mounted externally and I believe it was being pulled through the radiator. I need to bypass it to test this theory and drive it around a bit. I've already replaced the radiator, but there is still fluid appearing and I could visibly see the external cooler leaking. I need to use the van this weekend to help my mother move boxes to her new place, but I don't have the time to order another external cooler. Is it possible to just bypass the towing package external cooler, so i can at least drive the van in the mean time and get the coolant system bled properly.

 

As long as the one in the radiator is hooked up you are good for non towing running.

 

Thanks for the information. You won't believe how long it took me to get someone to simply answer that question on the internet. I guess I was asking in the wrong places.

I have another question though, I have a spare Bosch Electrical Temperature gauge and I was thinking of tossing that into the line.
I could use a "T" currently the way that it sits to close the loop and then once I install a new trans cooler, I can easily place it on either side (most likely the supply). Is this the right way to do it?

 

As long as it doesn't leak, ok. The supply side would make sense. However, the trouble with a "T" is the lack of flow by the sensor. It will push fluid into the leg the gauge is on and that fluid will tend to sit there.

I am not a transmission man, so don't sue me if you burn something up.

 

The C6 trans run very,very warm. They don't have a locking converter so they generate much more heat than a more modern trans does.Ideally you should have a temp gauge and an large aux cooler,downstream of the radiator to help shed some heat on a truck or van that you tow often with.

You can place a sending unit in the line either before or after the cooler(s) in the lines but it's a poor place. It will fluctuate greatly and you'll never get a true overall average of the trans temps.You really want it in the side of the pan about midway up the side somewhere.
I've done the inline readings before and all it will do is stress you out reading the high temps coming out of the converter.You'll be afraid to tow cus the high temps will trick you into thinking your pushing her too hard when in reality,the average reading you would get from mid pan wouldn't even be up to normal operating temps yet.do yourself a favor and don't do it.