Transmission AC cooler was leaking fluid badly so replaced with an aftermarket one from rock auto. $220 to de & regas the AC and ~$300 for the new condenser so all up much cheaper than the $2k+ quoted by my mechanic.
One of the tran-fluid inlet ports leaked initially and turned out to be a torn o-ring in the new part - so unscrewed and replaced with nut form old condenser.
Very straight forward job for DIY.