[Christer]

I plan to use the stock radiator w/ stock automatic cooler. My concern is if my automatic cooler is clean enough. It has been standing in the garage for ten years or so. We all know how the average garage looks like and I am a bit worried that there now is dirt inside the automatic cooler.

I think that Transman has adviced us to use a filter (only during start-up) on the return side. I plan to follow his advice. Do you think that this precaution is enough, or is it wise to clean the automatic cooler in some way, like leave it to the Pros or pour one or two pints of oil through it before the whole package is in the car?

Maybe I am a bit overconcious, but to have problems with my rebuilt 727 is the last I want. I have had enough of these kind of problems through the years. Thanks!

[transman]

Christer. If you are really concerned about how clean the cooler in your rad may be, then if you can, bypass it with a QUALITY external transmission cooler. If this is not an option for you, then do your very best to clean the cooler and cooler lines out. You can pour a mixture of 50% solvent, and 50% ATF in one of the cooler lines until it comes out the other. Let this mixture sit for a while, and then use compressed air to blow into one of the lines to flush out the system. Repeat this process, but the next time, blow the compressed air into the other cooler line. This is a method called backflushing the system. Next, take a clean rag and cover one of the cooler lines, and then blow air through the other one. If all you catch in the rag is a bit of transmission oil and solvent, then you've cleaned the lines as best as you can, short of taking your radiator to a radiator shop and having them replace the internal transmission cooler.
Please make use of the external filter as in my previous post, as unfortunately, the best cleaner of all for cleaning out transmission oil coolers is HOT ATF.
Hope this helps.
Graham

[Christer]

Thanks, Transman. Much appreciated.

The cooler lines should not give me any problems since I have bought brand new one´s not long ago (They are unused).

I will try to clean out the oil cooler in the same way as you have suggested. Thanks!