Jeep Grand Cherokee and Dodge Durango SUVs from the 2011 through 2014 model years are involved.
Chrysler says crimp joints in the brake boosters can corrode if they're exposed to water. If the water freezes, the boosters won't aid braking as they usually do.
Chrysler began investigating after some customers said their brakes felt too firm when pressed down. The company knows of one accident, but no injuries, due to the defect.
Dealers will install a shield to protect the boosters for free and replace boosters that aren't working properly.
Chrysler has since changed the design to make the boosters more corrosion resistant.
Chrysler will notify owners of the recall, which involves 867,795 vehicles.