Looking for answers 03 Tahoe LT

[MM60]

Front brakes heat up and drag. Mechanic shop replaced both rubber brake hoses and ABS pump and module and rotors and brake pads. Still the brakes dragged after driving about 5 miles. I put on new calipers (guide pins lubed). Replaced master cylinder. When I removed the mc from the booster, I heard a hissing. The mc plunger area had dirt and half of the black gasket was eaten away. I wasn't able to see inside the booster to check for fluid. I cleaned the booster up well where the mc bolts onto it and bolted the new master cylinder on after bench bleeding it. I bled the brakes in the correct order and very dark old fluid came out of the passenger side rear and also the other three bleeders but not as bad. I made sure to flush out the old fluid until new fluid appeared. Guess what? The damned brakes heated up and began dragging once again! The only thing not replaced yet is the power booster and check valve. I could sure use some good advice from y'all. I can't be the only one that has dealt with this issue.

 

[Big Mama]

Welcome to the forum from Virginia. I had a very similar problem after replacing my brakes. My problem was front left. My problem was guide pins an a cracked bleeder screw on the right rear. It drove me nuts. The bleeder kept me from truly getting all air out. The guide pins I removed and lubed 3 times. It finally went away.