After a four year probe, National Highway Traffic Safety Administration (NHTSA) has cleared General Motors Co. (GM) of a possible recall of about two million sport utility vehicles (SUVs) and pickups for possible corroded brake lines.

The NHTSA officially issued advisories that the corrosion of brake lines from 1999-2003 truck models were caused of wear and tear most likely from road salts during winter in the northern states. This investigation covered ten Cadillac, GMC and Chevrolet models, together with the Avalanche, Escalade, Yukon, Silverado, Suburban and Tahoe.

Last year, GM suffered major setbacks from the discovery of its faulty ignition switch that could cause airbag malfunction leading to accidents, among 2.59 million small cars resulting to a $35 million civil suit charges, criminal investigation and even congressional hearings. In 2014, a record of 64 million trucks and cars were recalled by US automakers, headed by GM at Detroit.

The NHTSA's safety information for vehicle owners of pickup models manufactured in 2007 and earlier in twenty one salt states including Washington, D.C., is regular salt removal by cleaning the undercarriage especially during winter, as continuous salt exposure could result to brake pipe corrosion.

GM stated it supports the agency's recommendations.

"GM has proactively suggested to consumers that they perform regular undercarriage cleaning and post-winter brake line inspections to check for wear," Alan Adler, a General Motors spokesman, wrote in an official e-mail.

GM has been continuously working on improving the quality of vehicle parts along with internal tracking of its own safety challenges. GM's CEO Mary Barra has redoubled efforts to clear the image of the company for defective vehicle parts.

According to papers released by NHTSA, the rusted GM vehicle brake lines created 3,049 complaints, of which 2,702 were compiled from the cold winter states, where road salt are present and some of these salt states do not have vehicle inspection requirements.

The GM manufactured trucks have steel brake lines that truck owners asserted are so rust-prone that they stop working without notice, which cause the brake fluid leaking. The lost brake fluid means an unexpected, sometimes tragic loss of braking power, the vehicle owners wrote in their complaints.

GM successfully contended the case that GM trucks would still halt safely even if one brake line fall short and that the corroded brake lines were part of routine wear and tear on GM models with a minimum of eight years when the probe started last January 2011.

Photo: Yahya S. | Flickr