2011 Sierra Brake Problem

[jstein55011]

My 2 month old GMC Sierra feels like it doesn't have power brakes, unless I pump the pedal once. It seems normal at low speeds, such as in a parking lot, but if you're going 30mph or more and push the brake pedal, it feels just like the old days before power brakes. Requires what I would consider excessive pedal effort to slow down the vehicle. If you take your foot off the brake momentarily and then reapply the brakes, it feels like it should. The dealer thinks there's nothing wrong. I've bought three of these trucks in the last seven years and I know what brakes should feel like after 42 years of driving. Any thoughts about what's likely wrong here?

[00Silverado4x4]

Possibly a bad brake booster. I don't know if your truck is vacuum controlled but if it is you could look at the line going to the booster for cracks/leaks. Also I'd try another dealer to get confirmation. I have never had to press & reapply for my brakes to work correctly. I have driven a vehicle (brother's '74 Ford Pickup), that did not have power/auto anything (4 speed manual, manual brakes, manual steering) so I feel your pain.