Normal. Cast iron will surface rust very quickly when exposed to moisture.
You can get a wire brush and remove it then spray it with some fluid film to slow the process down.
However, it’s just going to keep happening once the film wears off.
The key is to make sure you use a little anti seize on points where the wheel hub mates to the drum. That way, you won’t have an issue of rust building up and seizing the wheel to the drum later on down the road.
Normal. Cast iron will surface rust very quickly when exposed to moisture.
You can get a wire brush and remove it then spray it with some fluid film to slow the process down.
However, it’s just going to keep happening once the film wears off.
The key is to make sure you use a little anti seize on points where the wheel hub mates to the drum. That way, you won’t have an issue of rust building up and seizing the wheel to the drum later on down the road.