Wastegate repair (aluminum TIG build-up)

[jakeru]

I got an external 35mm type wastegate that wasn't manufactured quite right, so today I got to fixing it.

The problem was the surface for the banjo fitting of the boost pressure signal wasn't flat and was quite a ways off from square to how the banjo fitting hole was tapped, so I couldn't just file it flat either.

I fixed it by doing some TIG welding build-up around the threaded hole to build up the surface where it was low. To avoid needing to re thread the hole through this process, I just stuck a steel bolt into the hole and TIG built up some aluminum material around that bolt.

Then I carefully filed it flat (with the mating surface perpendicular to the axis of the threaded hole, of course) and chased the threads and... now it works! Good as new (No actually, make that *better* than new! )