After four years of study, NHTSA, GM, and the Pennsylvania DOT have determined that salt is bad for your car, truck or crossover. This is pretty obvious to those who live in the states where they spread sodium chloride and calcium chloride, but the level of detail of this study should remove any doubt.
NHTSA’s new advisory can be summed up by this statement from the text: “…owners of model year 2007 and older trucks, SUVs and passenger cars (should) inspect brake lines and 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.” Unlike the body-rot and surface rust we are all familiar with, and which Craig Fitzgerald discussed in his recent story about older Altimas and floor-rot, this is a warning that salt and corrosion can cause your vehicle to crash.
Back in 2010 NHTSA was alerted by an owner of a GM truck that the brake lines on the vehicle seemed to have suffered corrosion and failed. Eventually, the resulting National Highway Transportation Safety Administration’s (NHTSA) Office Defects Investigation (ODI) considered over 10.7 million GM and other automakers’ trucks and SUVs. There were 3,645 complaints and 107 reports of accidents, some involving injury. In the end, no specific defect was found. However, the study brought to light the fact that the brake tubes that were originally coated with an aluminum Galfan coating do corrode. During the study period, GM switched to a new plastic type of coating more resistant to stone chips called NyGal which seems to have been more resistant to salt and galvanic corrosion.
The NHTSA report issues the following recommendations for those drivers who operate their vehicles “where salt and de-icing chemicals are common in winter”:
- 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.
No recalls were announced by NHTSA. The study found that GM and Ford’s vehicles had about he same amount of corrosion and that Dodge (Ram) had slightly less.
At a recent meeting of the automotive press in New England, a lively debate over the issue of salt corrosion took place among the members, many of whom are longtime car restoration buffs. Many took the view that corrosion in cars in the Northeast is normal and should be expected. Others felt that changes to the road preparation materials have increased the need for vigilance. Either way, the new NHTSA report has proven that salt does cause corrosion and that the effects can be more serious than just cosmetic. To try to get to the bottom of the issue, John Paul, the Car Doctor invited a corrosion consultant to discuss this issue on his show this week. The basic remedy seems to be to wash the underside of your vehicle with clean water and to have the vehicle periodically inspected by those that can recognize the warning signs of brake line corrosion.
Colorado photo courtesy Youtube and Waterworkscarwash8