One problem related to brake master cylinder has been reported for the 2007 GMC Sierra 1500. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 GMC Sierra 1500 based on all problems reported for the 2007 Sierra 1500.
I have bought the truck used I have emailed GMC that I was having issue upon doing so they had sent me a phone number to call which I tried and it said it would not let me from my area I emailed them again and they did not reply. My master cylinder went out on my GMC Sierra 1500 wt extended cab and I found upon replacing the master that they used a 2006 master cylinder on what they call a 2007 vehicle . . Lost the brakes completely no wreck. What they did do was send me a letter in the mail stating my bumper to bumper warrenty was due to expire how convenient for them. I tried hard because I want to know did they use 06 on my 07 truck to obtain replacement parts it is important. Now a few months later I am noticing that undeneath the drivers side that one of the brake lines is starting to leak I still only have 48000 miles on this vehicle no way no how should the lines have rotted out this early or corroded Gmcs answer is it is out of warranty. Being on disablity I will have to come up with close to 300 dollars to replace all the lines before they blow out and cause me to have a major accident which GMC does not seem to care that they have installed defective parts that prematurely fail.