You may have a caliper sticking that may cause premature brake pad wear or rotor warpage. It could possible be a wheel bearing. It is best to have it checked out right away. You are talking about your brakes. Good luck.

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1990 190E 2.6
1996 Grand Voyager 3.3
1985 Mustang GT 5.0 5 SPD
1982 Suzuki GS 750T