news problems 04 chevy silverado

has anyone had any problems with a really really soft brake pedal;
it goes all the way to the floor when you step on it:
I took it to the chevy dealer & they tested it with a device that would measure 100 foot pounds of pressure. the only problem is they turned the truck OFF; so the system was not tested, they said no problems iwth the brakes this is one of many problems with this vehicle including frame beaming any one out there having the same problems; it seems to effect how the abs brakes work or should work

Sounds like a master cylinder, but check for leaks at the wheells and the tubing across the truck..jj

I have a 2006 GMC Sierra. When I left the dealer I noticed a vibration at 30-40 mph and 60-70 mph. Took the truck to the dealer the next weekend and the service guy said it was probably flat spots on the tires. He said to drive for 3000 miles or so and it would straiten out. So I called the salesman who sold it to me, he got me to bring it back in.They did the road force test,turned the rotors,Changed the tires to other rims, but no change.

I can't beleive how many times they use the excuse of, "its a flat spot"
Yeah because I make my car skid long distances at high speeds all the time.