black residue

[Sun.ranger]

I noticed this summer that there is black residue behind both tires I need to wash off. Is this from the tires or the brakes? Is this normal?

[mwebber78]

Perfectly normal but inspect your inner and outer tires for abnormal wear. You should see the diesel soot residue after driving from Maine to New Mexico - it's crazy from the big rigs.

[Geaux]

Be sure and check for axle seals and brake fluid etc.

[Sun.ranger]

Easy to check for brake fluid, but how do you check for axle seals? I assume since it is on both sides it was normal brake wear or tire wear.