SAFETY ADVISORY ON PREVENTING UNDERCARRIAGE CORROSION

April 9, 2015

Agency issues safety advisory on preventing undercarriage corrosion

WASHINGTON – On April 9, 2015 the Department of Transportation’s National Highway Traffic Safety Administration (NHTSA) issued a Safety Advisory and consumer video encouraging owners of model year 2007 and older trucks, SUVs and passenger cars to inspect brake lines. Owners are strongly urged to thoroughly wash the underside of their vehicles to remove corrosive salt after the long winter in order to prevent brake line failures that increase the risk of a crash.

The advisory was issued in conjunction with the agency’s closing of an investigation into brake line failures in General Motors trucks and SUVs built in model years 1999 to 2003. The agency spent more than four years investigating corrosion related brake failures in the vehicles and similar trucks and SUVs made by other manufacturers, but has not identified a defect that would initiate a recall order.

NHTSA also issued a closing report that details the investigation’s analysis of state safety inspection data and a survey of about 2,000 vehicle owners. The data indicate that the brake line corrosion seen in the GM vehicles was not unique. Similar vehicles using comparable brake lines experienced similar corrosion issues, especially in states using salt to de-ice roads in winter. NHTSA issued a broad safety advisory urging owners of older SUVs and pickups to take steps to prevent brake failure resulting from corrosion.

“While NHTSA can’t order a recall in this case, there is a safety issue that vehicle owners should address,” NHTSA Administrator Mark Rosekind said. “Older model vehicles, often driven in harsh conditions, are subject to corrosion over long periods of time, and we need owners to be vigilant about ensuring they, their passengers, and others on the roads are safe.”

NHTSA’s safety advisory urges owners of trucks, SUVs and passenger cars that are more than seven years old 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.
  

“If you own an older vehicle and live in a cold weather state where salt and de-icing chemicals are common in winter, we strongly urge you to take these steps,” Rosekind said.

NHTSA’s investigation stemmed from a vehicle owner’s petition in 2010, and covered about 6 million model year 1999-2003 GM Sierra, Silverado, Avalanche, Escalade, Suburban, Tahoe and Yukon vehicles.

NHTSA examined consumer complaints for brake line failures for all types of light vehicles and analyzed safety inspection data collected in Pennsylvania from 2008 through mid-2014. The agency’s Vehicle Research and Test Center in Ohio conducted a survey that gathered data from approximately 2,000 owners of GM and peer vehicles from the period. Investigators also examined 71 randomly selected vehicles in Massachusetts, New York, Maryland and Ohio.

While NHTSA received substantially more vehicle owner complaints about all types of GM vehicles than similar vehicles from other manufacturers, the higher rate of complaints appeared to be, at least in part, related to public attention given to the investigation. The Pennsylvania inspection data, VRTC survey and random NHTSA vehicle inspections all showed that both passenger car and light truck peer vehicles are subject to similar corrosion related failure rates. The coated steel brake pipes in GM’s vehicles under investigation were similar to materials used by other manufacturers at the time. Beginning in the late 1990s, manufacturers transitioned to plastic coated pipes that are in use today.

NHTSA SAFETY ADVISORY: PREVENTING BRAKE PIPE FAILURE DUE TO CORROSION IN OLDER VEHICLES

ISSUE: Model year 2007 and earlier vehicles may be susceptible to brake pipe corrosion that can occur after seven to eight years of exposure to winter road salts. If brake pipe corrosion is not properly addressed, there is the potential of brake pipe failure which could result in a crash.

Consumer Actions to Protect Against Brake Pipe Corrosion in Older Vehicles

1. Remove road salt that leads to corrosion:

• Thoroughly clean your vehicle, including the undercarriage, at the end of the winter.
  
  
• Regularly wash the undercarriage throughout the winter.
  

2. Monitor your brake system, including brake pipes, and other undercarriage components for corrosion or signs of brake failure:

• If you own an older vehicle in a cold weather state have a qualified mechanic or inspection station inspect the vehicle at least twice a year. If there are any signs of corrosion, inspect the brakes more frequently, at least every time you bring your vehicle in for service.
  
  
• Keep an eye on brake fluid level. Watch for changes in how your brake pedal feels and for signs of fluid leakage beneath the vehicle. All of these could indicate a leak in your brake pipes.
  

3. If you find severe corrosion that causes scaling or flaking of brake components (see the photos below), replace the entire brake pipe assembly:

• Do not replace just a portion of the assembly. Failure in one portion of the brake pipes generally means other sections of pipe are at risk of failure.
  
  
• Check with your manufacturer to see if they have pre-fabricated brake pipe kits to make replacement easier and potentially less expensive.
  

Background

NHTSA recently conducted an investigation of brake pipe failures due to corrosion in a large population of 1999 through 2003 model year full size pickup trucks and sport utility vehicles and found that the failures result from end of life wear out. Data show that this corrosion problem is linked to brake line coating materials that several manufacturers used during this time period.

Vehicles driven in the following salt states are more prone to corrosion related issues: Connecticut, Delaware, Illinois, Indiana, Iowa, Maryland, Massachusetts, Maine, Michigan, Minnesota, Missouri, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, Vermont, West Virginia, Wisconsin and the District of Columbia.

FREQUENTLY ASKED QUESTIONS:

How do I know if my car has a problem?

Have your vehicle’s brake system inspected for corrosion. Replace the brake pipe assembly if there is evidence of scaling corrosion in any portion of the lines (Figure 1). Every time you drive your vehicle, keep an eye out for leaking brake fluid and other signs of a compromised brake pipe, including your brake warning lamp or changes in feel, for example, if the pedal feels soft or spongy or if it feels like you have to press the pedal closer to the floor than normal before braking begins.

What should I do if my brake pipes fail?

If you experience a brake pipe failure while driving, press and hold the brake pedal with constant pressure to get the best braking performance. In most cases you will hear the antilock brakes activate. This is a normal part of the system’s operation and lets you know that the remaining brake circuit is functioning. Allow yourself more time to stop and additional space between you and vehicles you are following. Don’t pump the brakes, this will increase the distance it takes to stop your vehicle.

If you notice that your brake pipe is leaking, do not drive your vehicle. Inspect the brake pipes for corrosion or other potential causes of leaks. If the pipes are corroded the best thing to do is replace all of them at the same time. Partial repairs frequently result in multiple failures, often within a year of the initial failure, and can be more dangerous and more costly over the life of the vehicle. Check with your manufacturer to see if it offers a prefabricated brake pipe assembly kit which can reduce the time and cost of repairs.

Brake pipe corrosion from left to right: a) no corrosion, b) corrosion without scaling, c) corrosion with scaling, and d) severe scaling corrosion with leakage.

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