Tweaked 5300

I have an 2002 ext cab silvy with a 5.3L and the truck has 66,000 miles on it and i know around 27,000 new brake pads was put on the front and the back due to the incorrect placement of the front and rear pads from the factory and all the rotors were turned if I'm not mistaken. Then, around 32,000 or 33,000 miles then i started to notice the spongy brake pedal and told the service manager about it and the GM tech (which I knew pretty well) and he said he call GM TAC and they said theres nothing that they can suggest to replace if everything is in spec, but the tech did replace the EBCM, electronic brake control module and did power bleed it 10 times and that did make somewhat of a difference for sometime and then around 48,000 miles i had the Gm tech install the Russell stainless steel brake lines and he also power bled 3 times then too and the brake pedal with somewhat better than before, and now its seems around town driving, the pedal is kinda firm, and coming from a faster speed like 60 or 65 the pedal is almost at the floor and this is scary! And so from what I found out from this website it could be anything from a brake booster or a master cylinder or both! don't know why 99 to 02 year of trucks and their brakes suck really bad!! If theres any help from anyone about this, or anyone who has the same issue please provide me any updates or information would be great thanks.

PS Trying to take care of this before i lower my truck and throwing on some 20's

simonsez

Working at a GM dealer I've seen this many times. I would replace the master cylinder. Most times if you inspect the master cylinder where it bolts to the brake booster you can see evidence of leakage. It will generally run down the brake booster. Just because you don't see leakage doesn't necessarily mean the master cylinder is ok. I have seen the master cylinder leak past the seals internally and not see evidence externally.