Two problems related to brake fluid leak have been reported for the 2006 GMC Sierra 2500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2006 GMC Sierra 2500 based on all problems reported for the 2006 Sierra 2500.
While driving I noticed smoke coming from under the hood and a fluid dripping onto the floor of the truck. Then there was absolutely no brakes. Pedal to the floor. I was able to get it into a parking lot and coasted in neutral til it stopped on a parking curb. The brake line had rusted through and ruptured, and the fluid was spraying into a hole in the firewall and into the cab of the truck. This is the third brake line that has ruptured in such a manner. No warning at all, and then sudden loss of braking. The warning light did not come on until the truck had been sitting for over an hour while I was waiting for a tow, and a large amount of fluid had leaked out. I'm just glad this had happened at a low speed and not on an exit ramp from the freeway. The ruptures are occurring where the lines run flat across a support. This is a poor design.
Was ready to leave work,had foot on brake pedal,it felt spongey started truck,pumped it up it still felt spongey as I got to end of the road I was driving on I went to hit brake for stop sign/the brake pedal went right down to the floor and brake light/check idiot light and message came on dash,oil reminder as service brake failure came on up as the message. Barely was I able to stop had to shift truck to 3 low for additional engine braking as I got up to the intersection and almost blew through the stop sign,drove it bout a mile home,looked under truck and saw brake fluid shooting out and dripping off everything by the gas tank. Havent driven it since.