Service technicians may have incorrectly installed a shield to prevent water from damaging the brake booster in the Dodge Durango and Jeep Grand Cherokee.

Fiat Chrysler Automobiles has issued a follow-up recall for nearly 650,000 vehicles, including the 2011-2014 Dodge Durango and Jeep Grand Cherokee, that may have been improperly repaired in a previous campaign.The original recall focused on protecting the brake booster from corrosion and subsequent water intrusion. Rather than install a new brake booster with improved corrosion resistance, FCA instructed technicians to install a shield to divert water away from the booster.

Some technicians apparently failed to properly install the new shield, resulting in more complaints of braking problems and additional NHTSA tests to determine the root cause.

"An incorrectly installed brake booster shield may be less effective in diverting water away from the brake booster, creating the possibility for corrosion and subsequent water intrusion of the brake booster, which in a cold climate may freeze and limit the braking ability of a vehicle," recall documents note.

Dealers are now instructed to inspect previous repairs to verify proper installation.