A problem with Bendix ATR-6 air-brake valves has raised a safety alert and caused at least one truck manufacturer to halt deliveries of new Class 8 trucks.
It affects several other builders' trucks and 50,000 to 60,000 vehicles in total, Bendix Commercial Vehicle Systems says.
In very cold weather, intermittent air leakage can affect braking action, but service brakes and anti-lock functions continue, Bendix says on its website.
"A temporary remedy is available and a permanent fix is being prepared," said Barbara Gould, a Bendix spokesperson. "OEs are working with us to come to a resolution about what's right for their business. It's a defect in a valve that can only potentially occur in extreme cold."
Bendix notified the builders when it became aware of an identified the problem, according to the website. It also notified federal safety authorities.
"This issue potentially affects all vehicles utilizing the affected valves, including some, but not all, vehicles equipped with traction control or stability control systems," the Bendix website says. It involves ATR-6 valves made between Dec. 2, 2011, and January 18, 2012, but no others.
An alert by Bendix caused Navistar International Corp. to stop delivery of Class 8 trucks assembled with the offending valve. The builder's chairman, Daniel Ustian, yesterday told stock analysts that this will contribute to first quarter financial losses. Navistar also uses Meritor valves, which do not have the problem.
The ATR-6 is also used by Kenworth, Peterbilt, Volvo and Mack, Bendix says. The problem valves were installed in only 11 Mack trucks, a Mack spokesperson said. The other OEs could not immediately be reached for comment.
Daimler Trucks North America has not used the Bendix ATR-6 valve, says a DTNA spokesman, so Freightliner and Western Star trucks are not affected.
"In extremely cold conditions (at or below zero degrees Fahrenheit / -18 degrees Celsius), internal leakage can potentially develop, resulting in pressure being delivered to the affected service brake circuit," the Bendix website says.
"Pressure being delivered to the affected service brake circuit can cause intermittent or - in isolated cases - continuous brake application. During the brake application, ABS will still be operational and additional service braking is still available."
The "temporary remedy kit" contains an O-ring and a plug that, when inserted into the valve, disables its stability control function, another company source said. Information on the permanent fix was not available, but the remedy is "forthcoming," Bendix says.
The website includes instructions on how to inspect valves to determine if they are affected. Such vehicles should be taken to dealers for service.
The valve is located at a truck's rear axles, among air and electrical lines, a Navistar source said. Getting at it is easy and quick, but the appropriate parts must be obtained. The Bendix posting tells how to do this, too.
Some customers know about the problem but have told Navistar to ship trucks anyway, the source said.
Information about the situation is at http://www.Bendix.com/en/servicessupport/recallcenter/recallcenter_1.jsp .
Bendix says additional info is available by phone and e-mail. The Bendix ATR-6 Action Line is 1-800-478-1793, seven days a week, 7:00 a.m. - 8:00 p.m. ET, or email firstname.lastname@example.org or call 1-800-AIR-BRAKE (1-800-247-2725) option 2.
(Updated 2/7/2012 9:40 EST with information from Daimler Trucks North America confirming it does not use the valves.)