Egr cooler leaking externally?

[Nilao]

Lots of corrosion at the gasket mating surfaces. Called around and cummins doesn't have it, can't get it, and says the manufacturer has 0 in inventory. Spent several hours polishing by hand to remove as much as possible. I will use some anaerobic sealer to help seal the imperfections I can't get out. The oil cooler is an updated stainless steel version and it shows no signs of wear. I'm gambling it will not leak and reinstalling it with new o-rings. Found some online but they are not for my cpl number. I'm not sure if a different cpl cooler will work the same or not and I'm not willing to chance it. Will be getting new gaskets from cummins tomorrow.

[Nilao]

   

[Nilao]

Started reassembly today. I used a real thin layer of anaerobic sealant on the mating surfaces to try to seal up the small corrosion pits in the face of the oil cooler housing. Letting it cure overnight. The only thing I have left is to hang the turbo and refill the coolant system. I have a new oil and coolant filter and am going to change my own oil while I'm at it. It's due soon.

[Nilao]

All assembled refilled coolant system and....still leaking from the oil cooler header plate. Murphy hates me. Only thing I can think to do is use RTV sealant. Anyone have any ideas?

[Nilao]

I had an epiphany. Rather than pull the oil filter header off I plugged all the coolant ports and pressurized it to 20 psi. I found my leak. There is a pin hole in the aluminum itself. With no new plate available I'm left to my own devices to fix it. I'll see if any weld shops are open tomorrow and take it down there. If none are ill most likely try to braze it shut.

[Nilao]

I found one on eBay that had the exact same part number cast into the casting. The inside looks brand new, the outside is oil stained but looks good as well. I'll have to wait till Thursday for it to arrive but for $175 I think I can wait.

[Rawze]

Wow. What an adventure it has been so far.

[Nilao]

Yes sir. Had I not pressurized the system with the egr cooler off I would still be chasing my tail. I would never believe that the casting itself had a hole in it. That thing is a quarter of an inch thick in most areas and about an eighth in others. With the egr cooler on I could not see the joint at the top of the plate so assumed it was the gasket leaking. I got out my dremel out with a fine point bit and ground all the corrosion out and found it to be all the way though and once I wire wheeled the area I found an inch long crack in the casting as well in the same spot. That was the deciding factor to order a replacement. I had to settle for used as there are none to be had new.

[Magard]

Trying to weld aluminum that's been in oil and coolant is really hard to get right anyway. You probably would have more trouble with it any way.