HELP!! Rear Brake Caliper Sticking-I'm Stumped

2003 VW Jetta GL TDI

I had a similar problem about 5 or so years ago. Brakes seemed to drag, mileage dropped. I kept checking items, PB cable, etc.

Finally one day I was driving about 45 mph, and the brakes went on without touching the pedal. I was literally slammed into the steering wheel. Brakes were locked up tight. I managed to drive off highway to access road. Had car towed, and VW did replace under warranty the master cylinder and booster.
They had some problems with some units. No problem since then until recently. I just replaced the PB cables, with new heavy duty ones, but notice my rear rotors seem hotter than normal. I set PB to second click, and not a lot of tension on cable, I'm thinking I'm gonna have same problem soon.

coulee

I've been having similar problems...brake drag at lr, replace caliper (mostly because I broke the bleeder), then the rear hard lines, (other lines are about 3yrs old), and rr (another broken bleeder), complete flush including abs unit...still have intermittant hard pedal. If I read it all right..if I lift the brake pedal and the problem.clears-booster, if not master cylinder?

Hard pedal is the vacuum hose to booster having a crack

Rear calipers dragging is just the calipers being crappy . Even remanufactured ones. I changed two , one on each of my Golfs. One still sticks after pulling on parking brake and the other one releases normally

my scirocco's original calipers would stick the same way too . Replaced with a pair of brand new MK4 calipers and never had the issue again

Hard pedal can be a number of things...not just vacuum!
same with brake drag, there are many causes.
what company caliper did you use?

Great success

Background:

1. 2001 Jetta with 200k on the odometer.
2. Right rear caliper dragging. Not enough to make the brake disk glow but enough to produce a burning clutch smell. Brake pads wearing prematurely.
3. Right rear caliper replaced a little over a year ago with a reman from NAPA.
4. No VAG stamp on the reman caliper casting.

Troubleshooting effort:

1. Jacked rear of car to compare right wheel with left wheel. Left wheel spun with no brake drag at all. Definitely too much drag on right wheel.
2. Pulled up on brake pedal and spun right wheel. No difference in drag eliminating master cylinder related problems. This being a right side only problem also suggested master cylinder was not part of the problem.
3. Set/unset parking brake. Made sure parking brake arm was positively returned to stop.Still dragging.
4. Cracked bleed screw and got a bit a fluid. Still dragging but fluid flow seemed to point to residual pressure to the caliper.
5. Conclusion #1: flex lines making residual pressure. Replace flex lines.

Replaced flex lines:

1. Outer flex line replaced first. Problem persists. Should have replaced inner first to save money.
2. Inner flex line replaced. Felt fortunate to not have melted a hole in the fuel tank while using a torch to free up a line nut. Problem persists.
3. Conclusion #2: caliper is sticking. Replace caliper.

Replaced caliper with NAPA reman with VAG stamp on casting: problem solved.