brake problem.. help

This is a huge problem..

While going down the road today I hit the brakes and the brake pedal went all the way to the floor.. it stops pretty well when it does this also. I tap it and the brake pedal will rise again and then do the same thing all over again.

The odd thing is that everything else seems normal, there is still fluid and all, but I can not imagine why this is happening.

A couple weeks ago I bled my brakes using a power bleeder and all was fine. I have checked all around the car and everything seems normal.. no fluid anywhere and it is still at the correct level in the reservoir… any ideas?

Sounds like you still have air in your system. Once air gets in you May have to use the vag-com to bleed the ABS unit.

If for some reason one of the compartments was emptyed while bleeding. The bentley says When at least one chamber in the brake fluid reservoir is completely empty (e.g. leaks in braking system) the hydraulic unit must be bled using the VAG 1551 scan tool in function 04, "basic setting. This is a time consuming deal but works well.

can you give a step by step for that..

I've got a vag-com, but I cant believe something went
wrong..

I'm guessing I'll just re-bleed the system with the
vag-com as a refrence?

has anybody done this?

This is what you need to do the whole hydro unit. we have done this on 2 cars that we replaced the abs with abs/asr units. THis is a long drawn out afair but does work.

01-91

Basic setting, initiating

Special tools and equipment

V.A.G 1869 Brake filling and bleeder unit

Function 04 "Initiate basic settings" performs several functions:

Display group 001 is required to bleed the hydraulic system Page 01-91

Note:

The basic setting to bleed the hydraulic unit is only required when one chamber of the brake fluid reservoir is completely empty.

The basic setting is used to bleed the hydraulic unit only. The brake system must be bleed separately.



Repair Manual, Brake System, Repair Group 47


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01-92

Display group number 01: Bleeding hydraulic unit.

Note:

All functions which could previously be performed with V.A.G 1551 can also be performed with the tester VAS 5051.

- Connect brake filling and bleeder unit V.A.G 1869.

- Connect V.A.G 1551 Scan Tool and select (address word 03) "Brake electronics" with ignition switched on; Page 01-23

Rapid data transfer HELP

Select function XX

Indicated on display

- Press keys 0 and 4. (The function "Initiating basic setting" is selected with 04).

Rapid data transfer Q

04 - Basic setting

Indicated on display

- Confirm entry with key Q.


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01-93

Basic setting HELP

Enter display group number XXX

Indicated on display:

- Press keys 0, 0 and 1
- Confirm entry with key Q.

System in basic setting 1

Depress pedal and hold...

Indicated on display:

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs
Pedal comes back

System in basic setting 1

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 2

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 2

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-94

System in basic setting 3

Depress pedal and hold...

Indicated on display

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs
Pedal comes back

System in basic setting 3

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 4

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 4

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-95

System in basic setting 5

Depress pedal and hold...

Indicated on display

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs
Pedal comes back

System in basic setting 5

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 6

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 6

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-96

System in basic setting 7

Depress pedal and hold...

Indicated on display

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs
Pedal comes back

System in basic setting 7

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 8

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 8

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-97

System in basic setting 9

Depress pedal and hold...

Indicated on display

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs
Pedal comes back

System in basic setting 9

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 10

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 10

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-98

System in basic setting 11

Depress pedal and hold...

Indicated on display

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs
Pedal comes back

System in basic setting 11

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 12

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 12

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-99

System in basic setting 13

Depress pedal and hold...

Indicated on display

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs

System in basic setting 13

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 14

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 14

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-100

System in basic setting 15

Depress pedal and hold...

Indicated on display

- Operate pedal with substantial foot pressure and hold.
Pedal moves down
Hydraulic pump runs
Pedal comes back

System in basic setting 15

Rel. pedal; FR/FL bleed screw OPEN <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.

System in basic setting 16

Please wait...(10 secs.)

Indicated on display

Hydraulic pump runs

System in basic setting 16

Depr. pedal 10X; bleed screw CLOSED <3>

Indicated on display

- Press key 3 on VAG 1551 or arrow up key on VAS 5051.


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01-101

System in basic setting 17

Partial bleeding ended

Indicated on display

- Press key.

Rapid data transfer HELP

Select function XX

Indicated on display

- Press keys -0- and -6- to end output.

Rapid data transfer Q

06 - End output

Indicated on display

- Confirm entry with Q key.

Rapid data transfer Help

Enter address word XX

Indicated on display

- Press C key.
- Switch ignition off.
- Disconnect connections to V.A.G 1551 Scan Tool.
- Bleed brake system.

The basic setting is used to bleed the hydraulic unit only. The brake system must be bleed separately.

Repair Manual, Brake System, Repair Group 47; Bleeding brake system, vehicles with and without ABS

a little confusion here:

1) when you say fl/fr open are they both open or just one

2)Rel. pedal; FR/FL bleed screw OPEN <3>

does this mean release the pedal and open the bleed screw, or release the pedal with the bleed screw open?

This looks like it may take an hour!! Then I guess I just bleed the brakes like normal by moving around the car and opening up the screws one at a time while using my bleeding tool.. yes?

So far this seems to have fixed it, but I have not driven it very much.

I only opened the Front Right brake nipple during this process.. should I have opened both??

It was not that bad, but without a power bleeder.. you are out of luck.. the process uses about a liter of dot4

Birdman, can you answer Metro's (and also my) question above? I read it as both bleed screws are open when unit is cycled. Correct? Any other tips?

Sounds like you did it ok. the book says open both at the same time. the first time I just opened up the rt side and bleed it 3-4 times pulsing the controller in between. then the LF side the same way. Then went around and did all the brakes starting with the RT rear. I Found on the vag-com that it tells you what to do, then hit the up button till you get to 13 (i think). the vag-com and the Bentley are not very clear on the how toos. But have not had any problems on any of the cars i have do so far.

Thanks!