Pitted Aluminum Wheels

Where the bead seats on the rim it's normal to get some pitting. What causes it not sure. Some people say electrolysis. I think it's just general corrosion from some of the tire soap the shops use when being mounted.

 

The pitting is usually caused by the use of chemicals that some States use to salt the roads in the winter time.

The chemicals can seep into the pores of the aluminum and that creates the pitting process.

 

Sharp edges at the bead seat area should be filed smooth. Compressed air from a compressor with bad water separator can carry water like a garden hose sometimes!