Brakes and brake lights sticking for a 3 seconds after I release pedal

[RussGM]

Brakes and brake lights sticking for a 3 seconds after I release pedal mostly when you on the hill and after 3 seconds brake lights and brake calipers become freely at the same time and truck can go .

Checked all wheells they spin freely no sticky calipers !!! Drums in the back

2012 GMC Sierra 1500 2wd WT

75xxx miles 

[Zeke Kunkle]

I just had this problem.  A real wheel brake cylinder was leaking.  Had both rear cylinders replaces and it's like new.