Concerns about rust and corrosion came roaring back when in the last month we replaced brake lines on four Jeep Grand Cherokees. Each unit had over 100,000 miles on it, which was not remarkable since the newest vehicle was 9 years old. The brake line in question runs along the driver’s side frame rail just above the fuel lines (See Photo).
Let’s see, Ford Windstars get recalled for failing rear axles caused by rust which initiated a buy back effort by the manufacturer. Trailing arms on Ford Expeditions break in two due to rust causing the driveshaft to fall to the roadway and rusting brake lines on GM C/K Pick Ups are widespread enough that NHTSA elevates the inquiry to an engineering analysis status. Now Jeep Grand Cherokees start failing for the same problem. Hello, there’s a problem here.
Have you heard of the salt belt? This is the area comprised of these states: 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, and the District of Columbia. If you drive a vehicle registered in one of these jurisdictions, you should monitor your car’s underbelly because the roads you drive get treated with de-icers that are very unforgiving to that part of your car.
What usually happens in these corrosion generated failures is that recalls will be limited to these geographical areas, which is not to say that a vehicle that spends a lot of time in a ski resort shouldn’t be examined.
So what can be done? There was a time when car dealers would offer undercoating as a vehicle “get ready” option, but it was found that the coating could plug up holes in the body that were designed to allow moisture to drain from the vehicle. In addition, heat from warmer parts of the vehicle would cause the colder under car parts to sweat and the undercoating would encapsulate the moisture which actually promoted rust.
Hexavalent Chromium which was referred to as chromium 6 in the movie Erin Brockovich was used in the anti-corrosion process that treated automotive parts. The substance was found to be a carcinogen- a fact that drove the plot of the movie. It also drove the decision to discontinue its use as an automotive protectant.
It is notable that an industry that is developing telematics which will allow communications between vehicles and has safety systems already on the shelf which keep vehicles upright, detect other cars in their blindspots, and effectively restrain occupants in seemingly catastrophic collisions, cannot respond to this concern.
The known information in this case is that vehicles will outlast safety related undercar parts; that some geographical areas use substances that attack these parts and that the failure of these parts have an extreme and immediate consequence to safety. It is time to solve this problem.
United States Department of Labor, Hexavalent Chromium, www.osha.gov