DETROIT (AP) -- U.S. safety regulators are investigating complaints of brake problems on Hyundai Genesis full-size luxury cars.
The National Highway Traffic Safety Administration says in documents posted on its website Monday that the probe affects about 40,000 cars from the 2009 model year.
The agency has received 23 complaints of that drivers had to push harder than normal on the brake pedal to make the car stop. One driver crashed into a stopped vehicle while another had to use the emergency brake to stop, sending the car into a spin.
No injuries have been reported. Several complaints alleged that the problem was traced to a faulty antilock brake computer.
In one complaint, a driver from South Florida told NHTSA that as she approached cars stopped at a red light at about 30 mph, she tried to brake, but the pedal went all the way to the floor. "I was in panic mode as I started pumping the brakes and nothing," the woman wrote. The car started to coast to a stop, but the woman ended up hitting a car stopped in front of her, causing minor damage.
The car was towed to a dealer, where mechanics drained and replaced the brake fluid. The woman said her husband still questioned the car's safety, so a manager drove it during a weekend but couldn't duplicate the problem. The woman was told that the dealer couldn't replace any parts. She wrote that she is dissatisfied with how her dealer handled the situation. Her family now has a car "we feel is unsafe to be driving."
Another driver also complained that the brakes failed four times. A dealer replaced the brake master cylinder, but the problem didn't stop. "It is only a matter of time before a crash and possibly injury occur," the driver wrote. "Brakes are like jet engines. They really need to work all the time."
Messages were left Monday morning for Hyundai officials.
NHTSA investigators will determine if the problem is big enough to cause a recall.
It's the first investigation since the 16-day partial government shutdown began on Oct. 1.