Brake problems after front disks & pads replacement

I replaced the front disks & pads on my 2002 Jetta TDI today. Brakes was working perfectly beforehand. Now pedal goes to the floor and poor braking power. If I pump the pedal, it gets better.

1) Brake fluid colour looks good, honey colored
2) The pads on the driver sides was worn through (btw, here in South Africa brake sensor is on the passenger side)
3) I compressed the pistons completely to get the new pads in

Any ideas? Is there any way I could've introduced air in the system if the reservoir was full and I didn't disturb any part of the hydraulic system? (No leaks I can detect anywhere)

Anyway of testing/diagnosing the master cylinder?

Thank you...

From my old school thinking, pumping the pedal to get it to work suggests you need to bleed the brake system. Why dont you do the fluid replacement at the same time. Has it ever been done?

Could you have nicked the boot for the piston when you pushed it back? I've seen this once with a similar result.

Thank you for your replies...

1) The brake fluid was never replaced, though it should have been done by the dealership while they still serviced it under warranty, wasn't done according to the job sheets.

2) Checked ABS with VAG-COM just for in case, also went for a run this morning: ABS worked when I succeeded in braking sharply with pedal against the floor. It told me the master cylinder and ABS was still working.

3) The brake fluid was dirty, like swamp mud compared to new brake fluid.

4) I bled all four wheels from the wheels, there was some brake fluid too... but mostly air.

5) Afterwards the brakes were completely gone... making for a hair raising trip to the hardware shop for more brake fluid.

6) Phoned the stealerhip... quoted me $400 for a new master cylinder (R2800).

7) Tried one last thing... bled the master cylinder at both nipples, actually easy... connect a long tube to the nipples, open the nipple, push the brake pedal a few times and check for brake fluid running out, keep on filling the reservoir (no need to close the nipple on upstroke of pump). I started at the nipple furthest from the booster, was okay, not a lot of air... The one closest to the booster... JUST AIR, no brake fluid during the first 5 pumps.

8) Started the car on my drive way, hit the brakes and nearly broke my neck...

Costs: 1.5 liters of brake fluid, one bicycle inner tube for my home-made one man bleeder system and 3 scuba cylinders of air (have dive business, so no cost issue). About $17. But also replaced front disks and pads, another $140. Cheers stealers.

BTW: Autozone supplied me with 260mm disks the previous time I replaced it, the pads were eaten away to an interesting shape. Puzzled me a bit, then realised the disks should have been 280mm diameter - I didn't check, and wasn't bothered about 1/3 of pad sticking out at the edge of the disk... learning the DIY way.

Amen.

Gerrit Conradie said:

Thank you for your replies...

5) Afterwards the brakes were completely gone... making for a hair raising trip to the hardware shop for more brake fluid.

Click to expand...

You might want to double check that you have the correct brake fluid in there. DOT 4 is sometimes a little harder to find.

Thought because DOT5.1 was more expensive, it must be better, thus bought it. Luckily read up on standards and discovered what DOT5.x really is and prevented a disaster in time No, I have DOT4 in, quite commonly available here.

Thank you. Brakes are as new now!