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#1 Transmission oil cooler removal....

Posted: Sat Aug 08, 2020 2:28 am
by MichaelDesna
Hi Gentlemen,
The automatic transmission oil cooler that sits under (?) the radiator in my car just sprung a major leak and is squirting out AT fluid when the car is running. Does anyone have any advice on removing and replacing it, or is it part of the radiator. I can't find anything on it in the forums. Thanks, Mike

#2 Re: Transmission oil cooler removal....

Posted: Sat Aug 08, 2020 3:28 am
by bitsobrits
If it's still to factory spec I'm pretty sure it's part of the radiator. Could be an aftermarket separate unit, though, as many things could have been bodged on a 50 year old car. First thing to check is if the steel lines have been "supplemented" with rubber hose at any point as is often the case as this is a common failure point.

If it is spewing ATF then it most likely is an issue with the line, not the cooler itself, and that is much easier to deal with. I would resist the temptation to replace the line with anything but proper metal tubing. Making new lines from scratch or from FLAPS generic line is not terribly difficult, whether by you or your mechanic.

If the cooler is integral to the radiator, and the leak is not from the lines, then obviously it's a radiator out job with a full flush of the cooling system to remove any ATF that may be present. Again, the level of difficulty is not high, thought the amount of work involved to r & r the radiator and have it repaired is much higher.

#3 Re: Transmission oil cooler removal....

Posted: Sat Aug 08, 2020 2:30 pm
by MichaelDesna
Thanks, Steve. The lines going into and out of the radiator are good and not leaking. It's coming from right above where the cooling fans are. I'm going to take those off today to see if I can have a better view of what's going on. I'll keep you posted ! -Mike

#4 Re: Transmission oil cooler removal....

Posted: Sat Aug 08, 2020 5:04 pm
by christopher storey
Michael : get it off complete and take it along to a radiator specialist who will be able to pressure test both the ATF circuit and the water circuits . These things being brass and soldered do not last for ever because vibration eventually works its magic, but they have the great advantage over modern aluminium rads that they can be repaired

#5 Re: Transmission oil cooler removal....

Posted: Sat Aug 08, 2020 11:58 pm
by alfred
If the trany fluid has not mixed with the engine coolant then a quick temporary fix would be to get a dedicated trany cooler from Summit or some other shop and plumb the lines into it. There is room in front of the main rad to add a small tranny cooler. I did this so I could cool down the trany better. From what I was told In the dual function factory rad the engine coolant preheats the trany to 180F . I also added a trany temp gauge in the lines to avoid fluid boil overs.