Brake issue

This procedure details how to bleed the ABS pump when replacing brake fluid. This procedure is NOT necessary unless your ABS pump has gone completely dry. For normal brake work including fluid replacement, hose replacement, pad replacement, etc. this procedure is NOT necessary. Also, this procedure does not take the place of good ol' fashioned brake bleeding with one person operating the pedal while the other person opens the bleeder valves one by one and collects the discharged fluid.

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Uwe said:

If this is the procedure I'm thinking it is, it really requires the car to be up on a lift, with one person in the car using VCDS and actuating the brake pedal while a second person is under the car opening and closing the bleed screws, etc.

-Uwe-

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tomjv said:

Can this be done solo?

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Hey Uwe,
I have the car on stands(all 4 wheels off). THAT'S what I'm trying to find out. Can this be done solo?

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Address 01: Engine Labels: 022-906-032-BDF.lbl
Part No: 022 906 032 CS
Component: United 24V G 04wc
Coding: 00032
Shop #: WSC 00001
VCID: 5EBD9140DA282BEEC91-5178
9BWDH61J134074051 VWZ7Z0C7128452

No fault code found.
Readiness: 0000 0000

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Hi everybody from italy. I'm a satisfied VCDS owner, I'm not a professionist, I'm a mechanical and engine lover. I was reading all this forum looking for informations about VCDS bleed procedure, the legendary procedure, I found this thread, interesting. Old, but interesting.
Must say that people should write if the problem is fixed at the end, not only wait for answers and then disappear. So we can't know if solutions were right.
Anyway, I spent my last 2 years talking to VW official technicians, seeing officials VW instructions (in VW garages, not Bentley or others instructions), then reading thousands of web pages about people bleeding VW with VCDS in various absolutely wrong ways.

Now I talk about VW cars equipped with MK60 ABS unit, only ABS no ESP.
Must say that VW instructions ask to use a pressure bleeder at least 2 bar / 29 PSI, no other way to bleed. So procedures like the old "press and release pedal with 2 people" or like "vacuum bleed" (which works only at absolute atmospherical pressure) or home made/cheap "pressure bleed" which works at a too low pressure become completely inappropriate.
I'm surprised that VW instructions do not say anything about OBD bleed procedure and all VW technicians confirm that they never had to bleed any new/drained MK60 ABS unit in their career. The only way to bleed them is to pressure bleed, pressure must not be less than 2 bar / 29 PSI to get air out of ABS unit.
They say that OBD bleed procedure is requested only for MK60/EC1 ESP (and late versions) equipped cars due to very narrow conduits of the ESP unit.
I can confirm that I was able to bleed a drained ABS unit without VCDS, just using a 2,5 bar bleeder. I test drove the car and it braked correctly, then I tried also a VCDS bleed and the brakes were exactly the same. No differences.

Now I talk about our VCDS.
It has 2 advanced ABS-Brakes functions that are normally used:
03 - Output test
04 - Basic settings
What I report reading web pages is that people uses "03 - Output test" to bleed brakes! Crazy! Fool! This function is just to verify functionality of ABS valves, to check if brake is applied or not for every single wheel with brake pedal pressed or not. It's a long procedure and requests 2 people, one on board to press or release pedal, other off the car (which is lifted) to manually check if wheels are free or braked, just following detailed instructions on VCDS screen. No bleeder screw has to be opened during this test!
I read about people who says that were able to get air out of the ABS unit using the "Output test" and they believe to have done a good job. Ok, let's them be happy.

The only bleed procedure can be found in "04 - basic settings", selecting "group 1". It has four steps which are repeated in loop until user decides to stop. There is any massage to confirm that procedure is ended.

1) Starting procedure makes appear message "Press brake pedal and hold". You press pedal like a normal stop and istantly it drops near to the floor because ABS valves are opened and fluid goes into expansion chambers. Please keep pressing pedal like a normal stop, dont' let it. After few seconds we can hear ABS pump activated for a few seconds, fluid is pumped from ABS unit to the master cilynder, so pedal is pushed back with force, you can feel your foot pushed back. Please don't be scared, keep pressing pedal like a normal stop while it's moved back and it's very important you let pedal come back, don't try to keep it down to the floor, it must come back to the normal brake position.

2) Second step appears automatically. "Release brake pedal and open FL/FR bleed screws". Easy. Let the pedal, get off from the vehicle and open both front bleed screws. it's clear that there is no reason to open bleed screws if brake system is not under pressure.
This operation must obviously be done while a pressure bleeder is connected.

3) Third step appears only after confirm previous step. "Wait 10 seconds", ABS pump is automatically activated for 10 seconds. Brake fluid is moved from ABS unit to the master cylinder. (Must say that some people on the web believe that this pump activation is to pump fluid out of calipers, this is not true, fluid is pushed out by pressure bleeder, while ABS pump moves fluid from ABS unit to master cylinder).

4) Fourth step appears automatically. "Press brake pedal 10 times then close bleed screws". Another clue that this operation must be done with a pressure bleeder. In other cases, air will be sucked back every time the pedal is released. 10 pedal pressions just help old fluid (which is already pressurized) to be pushed out of the calipers in less time. They are not counted from VCDS in anyway, they are not counted from ABS unit, 10 pressions are a theorical number of pressions to help fluid to be pushed out. I believe that they are not really necessary, we can let the pressure bleeder does its work until new fluid comes out whitout touching brake pedal.

Now if we press "continue" button, VCDS goes back to the first step and repeats the 4 steps in loop. So there is no message which confirms that procedure is complete. We have to decide when to stop it. When we are sure that only new brake fluid is coming out with no air we can stop at the step 4, we close bleed screws and select "Done, go back" then "Close controller, go back" buttons on VCDS, ABS unit status will return normal and we can disconnect VCDS and pressure bleeder.

Some final considerations:

Why VW technicians use only pressure bleeder to bleed ABS units while an ABS unit bleed procedure is possible?
Many people goes crazy using wrong ways to bleed, they keep to get a spongy brake pedal, then they buy VCDS to perform ABS unit bleed but in many cases they don't fix the problem. That's because of the bleeding method, not of the VCDS.
I can suggest:
- Forgot old bleeding method "press and release pedal with 2 people". If there's any air bubble in the ABS unit, it will come back up into unit every time you release pedal, also if bleeder screw is closed. Fluid movement must be costant to take air out.
- Forgot vacuum bleeders, they are not serious, not only for low pressure but also because some air is ever sucked from bleed screws (Venturi effect), we cant' be sure if fluid is really coming out without air and an old bleeding method (press and release with 2 people) is anyway needed at the end.
- Cheap pressure bleeders make too low pressure, about 10/15 PSI, too far from 29 PSI requested from VW. So maybe that they are not able to push air bubbles out of ABS unit. In this case (and only in this case) I must believe that VCDS bleed function can help, especiallly in the step when it asks to press pedal 10 times. Maybe that this will help old fluid and air bubbles to get out of the ABS unit. I suggest to press and release the pedal very very slow to let time to cheap pressure bleeder to mantain pressure. If pedal is released too fast may be that air is sucked back into calipers.
- Pressure bleeders at least 2 bar / 29 PSI are professional and very expensive and normally are designed to contain several liters of brake fluid. I have mine, I'm lucky to have found a used one. Consider what is cheap for you. Take your car to a VW garage to do a good brakes job for next 2 years or spend a lot of time and money to do bad job on youself and get a dangerous car?

I'm happy to discuss about with anyone.

Regards and happy new year.

Click to expand...

AleZava said:

Hi everybody from italy. I'm a satisfied VCDS owner, I'm not a professionist, I'm a mechanical and engine lover. I was reading all this forum looking for informations about VCDS bleed procedure, the legendary procedure, I found this thread, interesting. Old, but interesting.
Must say that people should write if the problem is fixed at the end, not only wait for answers and then disappear. So we can't know if solutions were right.
Anyway, I spent my last 2 years talking to VW official technicians, seeing officials VW instructions (in VW garages, not Bentley or others instructions), then reading thousands of web pages about people bleeding VW with VCDS in various absolutely wrong ways.

Now I talk about VW cars equipped with MK60 ABS unit, only ABS no ESP.
Must say that VW instructions ask to use a pressure bleeder at least 2 bar / 29 PSI, no other way to bleed. So procedures like the old "press and release pedal with 2 people" or like "vacuum bleed" (which works only at absolute atmospherical pressure) or home made/cheap "pressure bleed" which works at a too low pressure become completely inappropriate.
I'm surprised that VW instructions do not say anything about OBD bleed procedure and all VW technicians confirm that they never had to bleed any new/drained MK60 ABS unit in their career. The only way to bleed them is to pressure bleed, pressure must not be less than 2 bar / 29 PSI to get air out of ABS unit.
They say that OBD bleed procedure is requested only for MK60/EC1 ESP (and late versions) equipped cars due to very narrow conduits of the ESP unit.
I can confirm that I was able to bleed a drained ABS unit without VCDS, just using a 2,5 bar bleeder. I test drove the car and it braked correctly, then I tried also a VCDS bleed and the brakes were exactly the same. No differences.

Now I talk about our VCDS.
It has 2 advanced ABS-Brakes functions that are normally used:
03 - Output test
04 - Basic settings
What I report reading web pages is that people uses "03 - Output test" to bleed brakes! Crazy! Fool! This function is just to verify functionality of ABS valves, to check if brake is applied or not for every single wheel with brake pedal pressed or not. It's a long procedure and requests 2 people, one on board to press or release pedal, other off the car (which is lifted) to manually check if wheels are free or braked, just following detailed instructions on VCDS screen. No bleeder screw has to be opened during this test!
I read about people who says that were able to get air out of the ABS unit using the "Output test" and they believe to have done a good job. Ok, let's them be happy.

The only bleed procedure can be found in "04 - basic settings", selecting "group 1". It has four steps which are repeated in loop until user decides to stop. There is any massage to confirm that procedure is ended.

1) Starting procedure makes appear message "Press brake pedal and hold". You press pedal like a normal stop and istantly it drops near to the floor because ABS valves are opened and fluid goes into expansion chambers. Please keep pressing pedal like a normal stop, dont' let it. After few seconds we can hear ABS pump activated for a few seconds, fluid is pumped from ABS unit to the master cilynder, so pedal is pushed back with force, you can feel your foot pushed back. Please don't be scared, keep pressing pedal like a normal stop while it's moved back and it's very important you let pedal come back, don't try to keep it down to the floor, it must come back to the normal brake position.

2) Second step appears automatically. "Release brake pedal and open FL/FR bleed screws". Easy. Let the pedal, get off from the vehicle and open both front bleed screws. it's clear that there is no reason to open bleed screws if brake system is not under pressure.
This operation must obviously be done while a pressure bleeder is connected.

3) Third step appears only after confirm previous step. "Wait 10 seconds", ABS pump is automatically activated for 10 seconds. Brake fluid is moved from ABS unit to the master cylinder. (Must say that some people on the web believe that this pump activation is to pump fluid out of calipers, this is not true, fluid is pushed out by pressure bleeder, while ABS pump moves fluid from ABS unit to master cylinder).

4) Fourth step appears automatically. "Press brake pedal 10 times then close bleed screws". Another clue that this operation must be done with a pressure bleeder. In other cases, air will be sucked back every time the pedal is released. 10 pedal pressions just help old fluid (which is already pressurized) to be pushed out of the calipers in less time. They are not counted from VCDS in anyway, they are not counted from ABS unit, 10 pressions are a theorical number of pressions to help fluid to be pushed out. I believe that they are not really necessary, we can let the pressure bleeder does its work until new fluid comes out whitout touching brake pedal.

Now if we press "continue" button, VCDS goes back to the first step and repeats the 4 steps in loop. So there is no message which confirms that procedure is complete. We have to decide when to stop it. When we are sure that only new brake fluid is coming out with no air we can stop at the step 4, we close bleed screws and select "Done, go back" then "Close controller, go back" buttons on VCDS, ABS unit status will return normal and we can disconnect VCDS and pressure bleeder.

Some final considerations:

Why VW technicians use only pressure bleeder to bleed ABS units while an ABS unit bleed procedure is possible?
Many people goes crazy using wrong ways to bleed, they keep to get a spongy brake pedal, then they buy VCDS to perform ABS unit bleed but in many cases they don't fix the problem. That's because of the bleeding method, not of the VCDS.
I can suggest:
- Forgot old bleeding method "press and release pedal with 2 people". If there's any air bubble in the ABS unit, it will come back up into unit every time you release pedal, also if bleeder screw is closed. Fluid movement must be costant to take air out.
- Forgot vacuum bleeders, they are not serious, not only for low pressure but also because some air is ever sucked from bleed screws (Venturi effect), we cant' be sure if fluid is really coming out without air and an old bleeding method (press and release with 2 people) is anyway needed at the end.
- Cheap pressure bleeders make too low pressure, about 10/15 PSI, too far from 29 PSI requested from VW. So maybe that they are not able to push air bubbles out of ABS unit. In this case (and only in this case) I must believe that VCDS bleed function can help, especiallly in the step when it asks to press pedal 10 times. Maybe that this will help old fluid and air bubbles to get out of the ABS unit. I suggest to press and release the pedal very very slow to let time to cheap pressure bleeder to mantain pressure. If pedal is released too fast may be that air is sucked back into calipers.
- Pressure bleeders at least 2 bar / 29 PSI are professional and very expensive and normally are designed to contain several liters of brake fluid. I have mine, I'm lucky to have found a used one. Consider what is cheap for you. Take your car to a VW garage to do a good brakes job for next 2 years or spend a lot of time and money to do bad job on youself and get a dangerous car?

I'm happy to discuss about with anyone.

Regards and happy new year.

Click to expand...

ivantichy said:

Nice post! One thing. If you open FL and FR ABS pump actually pumps fluid out of calipers, not back to master cylinder. Tested today. How did you find it is pumping back to master cylinder? I am very interested. It would make sense..

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