This truck has been a total disappointment. The under carriage, fuel lines, brake lines, transmission cooler lines, exhaust manifolds, virtually every bracket, etc has rusted through. Even the steering linkage. For a manufacturer to produce a vehicle like this and charge close to 30k for an dangerous truck is shameful. I have a 02 pontiac sunfire without a spec of rust on it, so I don't want to hear it's all because of treating the roads that this truck has rotted away.. oh and the rear bumper is rotted off as well. I received a call from the dealer wanting me to trade it for a new GMC.. I hung up on him

2ND TIME BRAKES HAVE GONE OUT--LINES HAVE RUSTED THROUGH BECAUSE OF INFERIOR MATERIALS. CONTACTED GMC AND THEY ACTED LIKE THIS PROBLEM HAS NEVER HAPPENED BEFORE AND ASKED A BUNCH OF STUPID QUESTIONS, WE LIVE IN FL (USE TO LIVE IN CHICAGO) AND NEVER HAD A RUSTED BRAKE LINE-HAVE A CAR A YEAR OLDER THAT HAS BEEN PARKED NEXT TO THE SIERRA AND ITS BRAKE LINES ARE GREAT IT'S A TOYOTA!! NEED A CLASS ACTION SUIT BEFORE SOMEONE IS KILLED FROM THESE RUSTING BRAKE LINES IF THERE HASN'T BEEN ALREADY. HAD A PARTIAL LINE REPLACED (COULDN'T AFFORD TO HAVE THE WHOLE LINE PUT IN AND NOW A NEW PART OF THE LINE IS RUSTED THROUGH - GLAD WE WEREN'T KILLED IN RUSH HOUR TRAFFIC. ASKED GMC WHY THEY WERE TRYING TO KILL US???? WE HAVE THE ORIGINAL BRAKE LINE IF ANYONE WOULD LIKE TO SEE THE POOR(OR NO) QUALITY STEEL TUBING THAT WAS USED-PLEASE LET GMC KNOW STEEL R U S T S...FOR THE IDIOTS THAT DON'T KNOW THAT.

This is the latest episode of mechanical failure with my 2005 GMC Sierra. I had AAA tow the truck to the GMC dealer yesterday. The brake system went out recently and I initially thought it was just a blown flexible brake hose on the driver side front. However, that proved not to be true. Instead, the problem is a totally rusted out set of steel brake lines throughout the truck. In this case the burst brake line is in the engine compartment. It is the line that runs from the antilock brake distribution module (attached to the frame beneath the driver seat). It runs along the frame, above the frame rail and past the steering box, and then makes a right turn beneath the radiator to the passenger side of the truck, where it exits into the wheel well and connects to the flexible brake hose on the passenger side. The steel line burst in the area adjacent to the steering box, so that it sprays brake fluid all over the steering box whenever the brake pedal is depressed. This quickly emptied the reservoir on the master cylinder – leaving almost no brakes at all. There is very minimal braking available with the pedal fully depressed the floor. I initially examined the system to see if there is any chance of a do-it-yourself repair but quickly abandoned that idea. All of the brake lines are badly corroded and covered with scale, so there is no chance of cutting out the bad segment, double flaring the ends, and splicing in a short segment to replace the rusted-out portion of the brake line. All of the brake lines throughout the truck are badly rusted and likely will fail again if left in place. The dealer service manager estimates that it will take one of his mechanics almost a full day to remove all of the bad brake lines and fabricate replacements (these lines are not available in prefabricated form from GMC. Each line must be fabricated, bent, double flared, and custom fitted to follow the old path of the original line – far out of range of my skills).

It is sad that a 2005 vehicle that apparently exposed to normal salt use in the Pennsylvania region (where I purchased it used 3-years and 11000 miles ago) cannot survive for seven years without complete decay of the hard steel line brake system. The truck only has 55,437 miles on it (I have only added 11,587 miles in three years since I bought it, averaging less than 4000 miles per year in an area of North Carolina that does NOT use salt on the roads). So most of the salt damage and corrosion had to occur in Pennsylvania before we even bought the truck. It is hard to believe that GMC products fair so badly in the northern states. It will cost approximately $600 to have the brake lines fabricated and replaced. There is also electrical wiring problems with the evaporative emissions control subsystem associated with the fuel tank and some of the exhaust sensors that needs to be repaired to clear a check engine light. That will add approximately $200 more to the bill. All of this needs to be corrected before I can put truck up for sale – and I must say I will be glad to see it go! Considering the truck's relatively short lifespan and low mileage the number of mechanical failures we have had with it are pretty high. I had much better reliability with my old 1996 Ford Explorer, and it had roughly triple the mileage of the GMC truck! And the Ford Explorer also existed on Pennsylvania roads and was exposed to the same salt. Needless to say this is my last GMC product. If I ever buy another truck I will be looking at Toyota or Nissan products and avoiding all examples from Detroit.