Originally Posted by
Americium
On my NA coupe the nipple on the reservoir had a small crack that was difficult to see, but it leaked. At the time I bought a new one from some retailer that is out of business now (maybe Bavauto). I installed it and guess what, it was also cracked at the base of the nipple. But this version had an internal brass tube reinforcing it. So I cleaned it up, roughed the surface and JB welded all around the nipple to seal the crack. It’s been a few years and it is still holding. Definitely a design defect.
Ya gotta love that JB Weld! Years ago, I actually fixed a major leak in my hot tub around the filter housing in the hot water. It's been about 12 years now, and I think that part of the tub will still be together when the rest crumbles! (And no - I am not in any way affiliated, compensated, or otherwise associated with the company) I have not found anything that I can't fix with that stuff.