Ok so i bought a g35 from a guy for 1700 had a blown motor fixxed that, so when looking over the car i noticed that the brake fluid was as black as oil, so i did a b brake flush with new pads and rotors and calipers, first 2 weeks brakes where smoking like hell, bleed the system again and it lossened up and doesnt smoke anymore. But brakes feel like they are holding alittle, i replaced master cylinder, abs, and abs module, blow out all lines cus it has some slug in system. After all that brakes feel alot better but still grabbing, someone put a bolt for brake switch so replaced it with rubber grommet, but still same issue idk what to do anymore last new thing i can out on the system is brake booster. Has anyone had this issue before if so can u please help me with some advice or where to start looking please i love this car but its killing my gas and it takes forever to speed up.

 

If you’re brakes are smoking and they are dragging so bad that it’s killing your mileage and acceleration I would replace every component again. The heat you are creating is literally frying the brake components and probably boiling the brake fluid. Likely your pads have gotten so hot that they will no longer be effective. And I can only imagine what it has done to your wheel bearings/grease/seals.

Anyway, back to your question, every time I’ve seen dragging brakes it was because of either a stuck caliper slide bolt, or a collapsed soft line going to the caliper. Since you replaced calipers I would be looking at the rubber lines going to the calipers.

 

Disconnect the ABS relay and see if that fixes the issue. Could be the computer triggering the ABS/VDC system and applying brakes while driving.

If that does fix the problem then start with a vehicle alignment. It's a pretty sophisticated computer controlled braking control system on these vehicles.

Just to verify you don't have any warning lights on the dash that are on correct?