Brake Bleeding with VCDS: A Complete Guide (Solution)

Hello forum,

I'm new here, and I've been working as a mechanic for several years.

I have a basic question regarding brake bleeding on a Skoda Fabia 1 with ESP.

According to Erwin (siehe Fehlerdatenbank) and Elsa, in addition to the machine ventilation at approximately 2 bar, the system also needs to be bled using a scanner (I have VCDS) if...
1. One of the chambers in the storage facility is empty.
2.: Generally, the system was open (either the brake hose or the piston was new).

Okay, I'm not experiencing any of those problems right now, but I don't quite understand what Erwin (siehe Fehlerdatenbank) and Elsa want me to do regarding the scanner venting. It says to open the ventilation screws on the left and right sides of the stainless steel casing... both at the same time????
Huh??
And finally, as usual, should it be vented again?

It's all a bit unclear.

As I said, I don't have the problem mentioned above, but I just wanted to know about it in general. After all, "use it or lose it."

Okay, and if I normally completely remove a saddle or disconnect a hose, I put a rubber stopper over the line. Does it still always require bleeding via a scanner (VCDS), or is a normal bleed sufficient in that case?

Thank you in advance for the clarification.

Hello,

Unfortunately, there are people who believe that simply bleeding the brakes is sufficient even when there is no actual braking power. Therefore, it is recommended to bleed the ABS valve block via the control unit.

This is a precautionary measure to ensure that there are no hidden air bubbles.

As long as no major parts of the braking system are empty and there is therefore a risk of air bubbles forming in the system, normal bleeding procedures are sufficient.

Additional bleeding of the valve block cannot cause any damage.

Generally, after a brake repair, you should test the system to its ABS threshold, so you can (hopefully) tell whether the system is working normally or not. And do this BEFORE you have to test it during an actual emergency braking situation in traffic.

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When I normally completely remove a saddle or disconnect a hose, I put a rubber stopper over the line; do I still really need to bleed it using a scanner (VCDS)

.
If you're fast enough, probably not. But who knows, maybe the colleague who's stuffing things in will take a break first and spill all the beans (and let some air in)?

As I said: If you want to eliminate all risk, you can also bleed the system through the control unit using VCDS. To do this, go into the ABS/ESP control unit (address 03) and select measurement block 1 or 2 in the basic settings mode, depending on the control unit. Which one is correct can be seen in VCDS itself.

Best regards, Rainer.

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As long as no major parts of the braking system are empty and there is therefore a risk that air bubbles will spread throughout the system, normal bleeding

is sufficient.

I see it the same way. / I feel the same way.

However, if the brake fluid reservoir has actually run completely empty and air has entered the valve unit, then it's usually very difficult to bleed the system effectively with a standard bleeding procedure.

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It says here: "VA li+re, open the venting screws... both at the same time???

"
Yep... then the valve block will be activated.
You then do this a few times on the front, and also on the back (although this hasn't yet permeated all "vas" testers. )

Okay, so you need two bottles to connect, and generally, if you're not doing it yourself, you should make sure that the pressure is actually set to 2 bar. Most people don't know this; they just routinely turn on the device.

Therefore, the traditional method of venting by foot is no longer recommended.


Have you ever had any experience with vacuum systems, specifically those that use suction instead of pressure to draw materials through the hot box (HBZ)?

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and generally, one should make sure that the pressure is actually set to 2 bar. Most people don't know this and simply turn on the device routinely.

"It's complicated... the manufacturer specifies different procedures."

Form:

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ABS Mark 60: To bleed the hydraulic unit of the ABS Mark 60, the filling pressure must not exceed 1 bar

.

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ABS Bosch 5.7 and Bosch 8.0: To bleed the hydraulic unit on Bosch 5.7 and Bosch 8.0 systems, a filling pressure of 2 bar is required.

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Pre-ventilation: Connect the brake filling and bleeding device, either VAS 5234 or V.A.G 1869, and set the corresponding pressure on the device. Ventilation sequence: 1. Bleed the front left and right brake calipers simultaneously. 2 - Bleed both rear brake calipers (left and right) simultaneously. - Keep the bleed valves open on the bleeder bottle's attached hoses until brake fluid free of air bubbles flows out. Subsequently, using the "basic settings" function with the tester -VAS 5051-, the hydraulic unit should be bled again. Initiate bleed procedure (to bleed the brake system).

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Ventilation (normal): Strictly follow the procedure for bleeding the brake system. Connect the brake filling and bleeding device, either VAS 5234 or V.A.G 1869, and set the corresponding pressure on the device. - Open the bleed valves in the specified order and bleed the brake calipers. ABS Venting Sequence - Model 60: Front brake caliper, left side. 2 - Front brake caliper, right side. Rear left brake caliper/wheel cylinder. Rear right brake caliper/wheel cylinder. Bosch 5.7 and Bosch 8.0 venting sequence: Rear right brake caliper/wheel cylinder. Rear left brake caliper/wheel cylinder. 3 - Front brake caliper, right side. 4 - Front brake caliper, left side.

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Post-ventilation. A second technician is required for this task. - Apply and maintain firm pressure on the brake pedal with your foot. - Open the bleed valve on the brake caliper. - Press the brake pedal all the way down. - Close the bleed screw when the pedal is fully depressed. - Slowly release the brake pedal. This bleeding process must be performed five times for each brake caliper. Ventilation sequence: Front brake caliper, left side. 2 - Front brake caliper, right side. Rear left brake caliper. Rear right brake caliper. After bleeding the brakes, a test drive must be performed. During this test drive, at least one ABS (Anti-lock Braking System) intervention must occur.