Over four years ago, in January of 2011, the National Highway Traffic Safety Administration launched an investigation of GM trucks and SUVs from model years 1999 to 2003. Yesterday, the agency closed that investigation, but it has issued a warning for drivers -- not just GM drivers, all drivers.
The probe affected a range of GM vehicles, including popular models like the Cadillac Escalade; the Chevrolet Silverado, Suburban, and Tahoe; and the GMC Sierra and Yukon. The investigation ultimately included 2,702 complaints about premature brake-line corrosion in those vehicles. At least 88 collisions have been linked to the problem, as well as 20 injuries (though thankfully, no fatalities).
The investigation was focused on salt-belt states -- that is, northern states that use salts to de-ice roadways in winter. The list of states included were Connecticut, Delaware, Illinois, Indiana, Iowa, Maine, Maryland, Massachusetts, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia, and Wisconsin, plus the District of Columbia.
The probe uncovered enough problems with GM vehicles to reach stage two of NHTSA's recall process, the engineering analysis. That's the phase during which NHTSA staff attempt to recreate problems in lab settings. However, in this case, the agency's Office of Defects Investigation couldn't find a common defect that was causing brake-line failures.
Instead, the ODI determined that the failures stemmed from a combination of wear and tear and inadequate maintenance:
"ODI’s investigation did not identify any specific defect conditions that were causing or contributing to the brake pipe failures. Nor did the analysis isolate the problem to any subject vehicle sub-populations when analyzed by vehicle type or production range. The investigation found that vehicles experiencing brake pipe corrosion failures were likely to have general patterns of excessive corrosion on the majority of the brake pipe assembly and appear to be occurring due to expected wear out for the brake pipe coating material used in the subject vehicles and the environmental conditions in severe corrosion states."
The problems were found to be most severe in vehicles that were more than seven years old.
And so, NHTSA has launched a safety campaign. It's targeted not just a GM owners, but at all motorists in salt-belt states. Among other things, the campaign encourages motorists to:
- Maintain their vehicle and prevent corrosion by washing the undercarriage regularly throughout the winter and giving it a thorough washing in the spring to remove road salt and other de-icing chemicals that can lead to corrosion.
- Monitor the brake system for signs of corrosion by having regular professional inspections and watching for signs of problems, including loss of brake fluid, unusual leaks and a soft or spongy feel in the brake pedal.
- Address severe corrosion, marked by flaking or scaling of the metal brake pipes, by having the full assembly replaced.