U.S. safety regulators are warning owners of older model vehicles in "Rust Belt" states to get their brake systems checked for corrosion. The "Rust Belt" is where salt is used to melt snow and ice on roads, which can increase the chance of corrosion on cars and trucks over time.

The advisory stems from research by the National Highway Traffic Safety Administration to determine whether rust-related problems on brake systems were a safety defect on about 2 million GM trucks and SUVs. NHTSA closed the investigation without a recall of the GM vehicles which would have effected model years 1999 to 2003, including Chevrolet Silverado, GMC Sierra, Chevrolet Suburban, Chevrolet Tahoe and GMC Yukon.

NHTSA has issued an advisory, asking owners to wash their cars regularly and have their brake systems inspected during cold weather in Rust Belt areas. This advisory has expanded to owners of any vehicle made by any manufacturer from the 2007 model year and earlier.

A zinc-aluminum alloy widely used to coat brake systems until about 2007 was more susceptible to rust than the nylon and plastic coatings that replaced it, says a NHTSA official.

"While we are not issuing a defect notice, there is a safety issue here and that safety issue is the combination of time and road salt creating a corrosion problem in these older vehicles," a NHTSA official said.

Vehicles in the these states are more prone to corrosion-related problems to brake lines and brake pipes: Connecticut, Delaware, Illinois, Indiana, Iowa, Maryland, Massachusetts, Maine, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia, Wisconsin and the District of Columbia.