Federal safety regulators opened an official investigation on faulty tire valves installed as original equipment on more than one million 2007 Ford cars and trucks, according to Consumer Reports.
The valve stems in question were made for Dill Air Control Products of Oxford, N.C. by Shanghai Baolong Industries Co. in China.
The National Highway Transportation Safety Administration started investigating the valve stems this past May after they were linked to a rollover crash of a 1998 Ford Explorer that killed a Florida man a year ago.
Cracks in valve stems can cause tires to lose air, and such air loss at highway speeds can result in tire failure and a loss-of-control crash.
NHTSA says it has identified 37 complaints of cracked and leaking tire valves in 2007 models of Ford vehicles.
The models identified include Grand Marquis, F-150, Mustang, Edge, Fusion, Expedition, Explorer, MKX, MKZ, Milan, Focus and Escape.
Eleven complaints allege that loss of tire pressure caused by cracked and leaking valves resulted in under-inflated tires needing replacement.
In addition, 23 of the 37 complaints said more than one valve was found to be severely cracked or cracked and leaking and needed to be replaced.
Dill informed NHTSA that as many as 30 million of the suspected valve stems have been distributed in the North American market.
Soon after the original investigation was opened in May, one U.S. auto parts distributor, Tech International of Johnstown, Ohio, issued a recall on some of the faulty tire valves it had sold under the Topseal brand, also manufactured by Shanghai Baolong.
Ford Motor Company uses valves stem supplied by Topseal as original equipment on its vehicles.
In documents on the newly-opened Ford probe, NHTSA says the original equipment snap-in tire valves may crack due to poor ozone resistance.
"Air leakage from a cracked tire valve may result in tire damage, which could affect vehicle control," said NHTSA.
Most consumers will have a have a hard time figuring out with any certainty if they have any of the defective valve stems on their tires.
That's because there is no visible identification of the valve once a valve stem is installed.
The only way to view the manufacturer’s identification and part number found on the base of the valve is to remove the tire from the wheel and inspect it from the inside.
Consumer Reports says motorists should conduct a visual inspection of their valve stems to check for cracks.
Move the top of the stem around, checking for any sign of cracks in the base of the stem where it meets the wheel.
Consumer Reports also recommends that you check your tire pressure every month and if one or more tires continually need to be topped-off, it may be a sign of a leaking valve stem or tire puncture.
If a valve stem is found to have cracks, have it replaced as soon as possible and as a precaution replace all the other valve stems at the same time.