After the vehicle has been parked for some time, like in the morning or after work, the first time I push on the brake pedal the brake pedal goes way down, almost to the floor. There is sufficient braking action to stop, however the pedal travel is excessive. After the engine is running the pedal travel seems to go back to normal. After about 10 minutes, 5-6 miles the brake pedal becomes extremely sensitive, just barely touch the pedal and I get immediate braking. Then the brakes feel like they are dragging. If I put the truck in neutral and let it coast it comes to a stop. If anyone has any ideas I would greatly appreciate any help.
Thank you.

 

Check the black rubber hoses that attach to your calipers, sometimes when they go bad they implode
on themselfs not releasing afternoon you take your foot off the peddle

 

There's not really a good way of checking them. Need to replace.
Plus it seems you have air in your system. That explains the sensitivity warm v cold.

When did you have brake work done?

 

I had to replace a bad caliper on the front about a year ago. I had new brakes put on about a year before that. Approximately

 

I think you need a proper professional diagnosis.
From the length of the MC actuator pin on the booster to replace of flex lines and brake system purge.

 

I checked the record, Brakes done on 9/27/07 at 57936 miles. Replaced a bad right front caliper on 1/24/10 at 88975. I have not had any problems since. I think I have isolated the problem to the front brakes, both equally. Brakes dragging on the way home, about 7 miles. Stopped half way and checked wheels, no excessive heat. Checked when I got home and the fronts wheels were significantly hotter then the rears. I will get the complete inspection hopefully tomorrow.

 

Front are ALWAYS hotter than rear. Meant to be that way

 

Alot hotter, thought I could smell brakes, any ideas?

 

I have had the ABS light and Brake light illuminated for a month or so now. I had the truck diagnosed by Chevy and the codes indicate a bad EBCM. The lights are not always on, first start of the day they are not on. Recently it seems that the lights come on and that is when the pedal becomes extremely sensitive and the brakes start dragging. Could this be related? I thought the bad EBCM only would cause the anti-lock brakes not to function.

 

Dunno.. not a brake expert but I wonder what effect on pedal if you just pulled the ABS fuse