i just finished replacing the front brake calipers on my wife's 2003 Passat. The passenger side was sticking, and the driver side had a fair amount of rust on the piston, so i decided to replace them both. After replacing them, the brake pads, and then bleeding the system, i'm still having issues. The brake pedal isn't fully returning, i'm still getting a brake fault error on the console, and when driving it, it feels like i'm driving while pressing the brake pedal down, and it won't go over about 25mph. There is also an acrid, burning smell. When i have the front end lifted off the ground, i can put the car in 1st gear (it's a manual transmission) and the wheels turn, but the speedometer doesn't go about 10mph. With it lifted, the brakes seem to be working as they should, but the brake lights stay on for about 30 seconds, or until i yank the pedal back up by hand.

i'm not seeing any fluid leaks anywhere (including any of the lines at the reservoir). i'm not hearing any whistling vacuum leaks. When the car is off, the pedal is very firm. When the car is on, the pedal feels normal, but after driving a short distance i can feel the resistance building. i double-checked to make sure i had the correct amount of brake fluid in the reservoir. If i turn the wheels by hand and have my son press the brake pedal the wheel stops immediately, and will move again as soon as he releases the pedal, so i don't think it's an issue with the fluid returning back up the line.

i'm at a loss as to what i should check next. Any suggestions would be greatly appreciated.

 

Possibly a bad brake line (the rubber section) may be deteriorating and not allowing the fluid back as quickly as it should. Do any of them seem spongy or even show signs of seepage?

 

As mentioned, the pedal felt like it was supposed to. Firm with key off/engine off. Normal feel with key on/engine off. No sponginess.i had checked to see if some of the hose had deteriorated, causing a flap of rubber to act like a one-way valve (pump the brakes while off, wait 30 seconds, crack the bleeder valve and if fluid spurts out it's an indication that the fluid is getting trapped), but even that seemed okay. Since the hoses weren't expensive, i replaced them. Everything felt perfect...as long as i pulled the brake pedal up with my toe. i took a look under the dash and found the hard flap of plastic that's supposed to be behind the pedal had gotten itself in front of the pedal at some point yesterday (it wasn't like that before). After moving that back into place, everything is fine again.

 

Great success!