The recall affects cars from the 2005 through 2009 model years sold in 20 states and Washington, D.C., where salt is used to clear roads in the winter.
Subaru says in documents filed with the U.S. National Highway Traffic Safety Administration that salty water can cause the brake lines to rust and leak. If fluid leaks, it could take longer for drivers to stop the cars, increasing the risk of a crash.
The problem was discovered in internal testing and no related crashes or injuries have been reported, Subaruspokesman Michael McHale said in an e-mail. Subaru is recalling the cars as a precaution. Owners of the cars should take them to a Subaru dealer for inspection, he said.
The cars were made between December of 2003 and April of 2009.
Subaru says it is still totaling the number of vehicles affected by checking state vehicle registrations. The company sold more than 400,000 Legacy and Outback vehicles during the affected years, according to Ward's AutoInfoBank. But McHale said Subaru estimates that 200,000 are covered by the recall.
Subaru dealers will check the cars for leaks. If leaks are found, the brake lines will be replaced. If there are none, mechanics will apply an anti-corrosion wax. All the work will be done at no cost to owners.
McHale said there are front and rear brake lines, and both would have to have severe corrosion for there to be a problem. "What you'd notice is a decrease in pressure and an increase in stopping distances," he said.