Originally Posted by Diesel911

I read thread concerning the installation of the repair nipples and you needed "The thread tap size is 18mm by 1.5mm. The drill size for the pilot hole is 21/32 inches, I don't know the metric equivalent." And, the member went on to say it took more time to clean out the metal chips from inside the cooler than it did to replace the nipples.
If you put thick Hi-temp grease in the flutes (grooves) of the drill and tap most of the metal chips will get trapped in the grease and make the cleanup easier.
Also good news is that all the oil comming back from the oil cooler has to go through the oil filter.