Fade

[RichardSEL]

UK '06 B6 tFSI 3c0 chassis estate 52k mile - standard original TRW calipers with standard TRW pads changed about 2k ago - no VCDS faults - Discs are original from factory - Autohold's fine as is EPB - Fluid resovoir level seems to stay at same level - there's no evidence of leaks at calipers, they were bled thru after pads' change

Usual in town driving brake operation is normal and sharp if needed at in town speeds, and brake pedal is hard and at nearly top of travel.

At speed there is a slight fade soas the pedel very, very gently sinks. Braking is even and there's no drift to either side. Have done brake adaption in VCDS and no change.
But there's not ever been yet a flush through of brake fluid and replacement with fresh. Am I getting a symptom of this? Or something more severe? Not a mechanic so your experience welcome!

Address 03: ABS Brakes Labels: 3C0-614-095-C2.clb
Part No SW: 3C0 614 095 Q HW: 3C0 614 095 Q
Component: ESP 440 C2 H015 0003
Revision: H015 Serial number: 0667233697
Coding: 0013731
Shop #: WSC 05311 000 00000
VCID: 3041DD31A338729

No fault code found.

Address 53: Parking Brake Labels: 3C0-907-801-53.clb
Part No SW: 3C0 907 801 B HW: 3C0 907 801 B
Component: EPB VC8HC001 013 0001
Revision: 013
Coding: 0000012
Shop #: WSC 05311 000 00000
VCID: 21672875F8D2CB1

No fault code found.

Thanks
RichardSEL

... it's only a hobby, only a hobby, only a...

[RichardSEL]

Just been on the motorway, took to legal limit and when nothing behind braked hard. ABS came on with a muffled repeated thumping together with hazards. But pedal went to about two thirds of travel

Anyone?
RichardSEL

[Elwood]

Start with a fluid flush. Fluid should be flushed every two years, not every six. Make sure you cycle the ABS pump in the process.

[RichardSEL]

Start with a fluid flush. Fluid should be flushed every two years, not every six. Make sure you cycle the ABS pump in the process.

Thanks John it's in my Bentley list too, should've had it done before...
Is ABS pump cycling a function in VCDS?

Cheers
Richard

[RichardSEL]

Thanks John it's in my Bentley list too, should've had it done before... (shame)
Is ABS pump cycling a function in VCDS?

Just found service book, it was done in Nov. '08, still too overdue though...

[Elwood]

Is ABS pump cycling a function in VCDS?

Yes.

[RichardSEL]

Yes.

Right, had the flush thru done. Asked the VAG-certified techie whether I should do the re-adaption of ABS and he said no. Tried the repeat of previous test: took vehicle up to legal limit and braked hard. Slight squeal off-side and ABS came in far more smoothly than before. All perfectly streight under this braking. But this time no "thump-thump-thump" of ABS coming in and out
Yesterday used VCDS to reset ABS to "factory defaults", and brakes do seem harder under pedal and more responsive. But havn't done same hard-braking test yet.
Do the brakes/ABS module have to re-learn their operation again?
See that in VCDS there are a series of setups to do concerning angle etc. But the Wiki says some of these have to be done with all four wheels off the ground. Havn't touched any of these settings.

How far should I go with re-adjusting these other adaptions?

[RichardSEL]

This is the log I got after doing re-set to basic:

Address 03: ABS Brakes
Control Module Part Number: 3C0 614 095 Q
Component and/or Version: ESP 440 C2 H015 0003
Software Coding: 0013731
Work Shop Code: WSC 05311
VCID: 3041DD31A39FEA98915

Advanced Identification
Serial number: 0667233697
Identification: GNO-000
Revision: H015
Date: 23.02.06
Test stand number: ÿ
Manufacturer number:
Flash Status
Programming Attempts: 1
Successful Attempts: 2
Programming Status: 00000000
Required Conditions: 00000000
Flash Tool Code: 394758 024 12337
Flash Date: 23.02.06
Misc.
Hardware number: 3C0 614 095 Q
Lot Number: K03
VCDS Info:
Labels: 3C0-614-095-C2.CLB

Address 03:3C0 614 095 Q channel 0 adapted from --- to 000

As usual, more info from those in here that know what they're doing very welcome!

[RichardSEL]

After having had the help in the VCDS forum that if there's no fault in the control modules showing then there's little can be done (words to that effect), took to the same motorway yesterday after some miles of mixed motoring without changing anything more.

Previously had a muffled thump-thump-thump from front end as ABS came in and out (control module also gave the signal to switch on hazards) Had the flush thru and re-fill, re-adapted ABS module, and believing I should also do a basic brakes' adaption from the Wiki site did that too.

Tried again yesterday same speed 60mph streight line and whilst brake pedal travel is certainly less, and control module activates the hazards, the ABS function is much quieter and appears faster in operation -- more of a thrum-thrum-thrum.

Just concerned that I might've lessened the ABS's operation and effectiveness -- but don't know which is correct: the before or after? Have I done this the wrong way round i.e. should I have done the basic adaption first or the ABS module first?

Address 03: ABS Brakes
Control Module Part Number: 3C0 614 095 Q
Component and/or Version: ESP 440 C2 H015 0003
Software Coding: 0013731
Work Shop Code: WSC 05311
VCID: 3041DD31A39FEA98915

Advanced Identification
Serial number: 0667233697
Identification: GNO-000
Revision: H015
Date: 23.02.06
Test stand number: ÿ
Manufacturer number:
Flash Status
Programming Attempts: 1
Successful Attempts: 2
Programming Status: 00000000
Required Conditions: 00000000
Flash Tool Code: 394758 024 12337
Flash Date: 23.02.06
Misc.
Hardware number: 3C0 614 095 Q
Lot Number: K03
VCDS Info:
Labels: 3C0-614-095-C2.CLB
--------------------------------------------------------------------------------
Address 03:3C0 614 095 Q channel 0 adapted from --- to 000

[RichardSEL]

Just concerned that I might've lessened the ABS's operation and effectiveness -- but don't know which is correct: the before or after? Have I done this the wrong way round i.e. should I have done the basic adaption first or the ABS module first?
--------------------------------------------------------------------------------
Address 03:3C0 614 095 Q channel 0 adapted from --- to 000

Anyone?