According to Sears PartsDirect, softener residue is a common cause for brown spots on clothing. Rust, mildew or mold inside the machine and failed hardware may also cause stains on clothing.
Clothes softener can build up inside front loading washing machines. After a time, the softener will begin to wear off onto clothing, leaving brown stains. To remove softener buildup, Clorox advises customers to run an empty wash with chlorine bleach, washer cleaning tablets or oxygen bleach.
Mold and mildew that cause stains on clothing can be identified by an odd, musty or sour odor when washing clothes. Today's Homeowner advises removing and cleaning the dispenser and cleaning the gasket on the door of the machine to remove mold and mildew. Leaving the front door of the machine open when not in use prevents new mold and mildew from accumulating. According to Clorox, using commercial washer cleaning tablets or bleach to clean front loading machines reduces mold and mildew.
Today's Homeowner advises using the recommended amount of powder HE detergent and dryer sheets or dryer balls to prevent buildup inside front loading washing machines. According to Appliance Repair ACE, an oily smell combined with brown stains on clothing may indicate a hardware failure. Appliance Repair ACE recommends replacing the main seal.