I had a +/- 20 year old intercooler "rebuilt." Apparently this was done by welding up one of the multiple lengthwise tubes the raw water runs across. Unfortunately all the tubes (which cool both the transmission and the fuel) were in equally poor shape. Shortly thereafter another went bad and damaged my FlowScans and filled my transmission with water.
On my 6V-92TA intercoolers the outer shell looks solid. It's welded, but if it can be taken apart and the entire tube set replaced this might work. Otherwise a new replacement is in order, might as well get one for the other engine while you are in it because that one won't be far behind.
My DD original coolers had their zincs on the top side. With engines off only the last quarter inch of the zinc was immersed. This was rapidly used up, the like-new top portion was then thrown away. My new intercoolers have the zinc at the bottom, much more metal protecting the system. I hope this solves the problem.
