What is the brake bleed sequence?

[hangman]

Hey guys,

I haven’t been here in a while. I have a 2013 Jetta sport wagon TDI. I just did the back brake pads & rotors. Tomorrow I’m doing the front brakes.

I’ve got the correct brake fluid however, I don’t know what the correct bleed sequence is supposed to be for this vehicle? In other vehicles, I did the wheel furthest away from the master cylinder. However, if there is a different brake bleed sequence I want to make sure I do this one correctly.

Thanks for any helpful information!

 

[oilhammer]

Bleeding sequence:

1 - Bleed left front and right front brake caliper together simultaneously.

2 - Bleed left rear and right rear brake caliper together simultaneously.

- With bleeder bottle hoses attached, leave bleeder valves open long enough that brake fluid exits without bubbles.

Then hydraulic unit must be bled once more via function "Basic setting" using Vehicle diagnostic tester.

Initiate basic setting (to bleed brake system):

Honestly, if you are just exchanging the fluid, it really won't matter so long as you don't let any circuit get too low. The above assumes you have a pressure bleeder.

Doing it with a helper:

Bleeding sequence:

1- Front left brake caliper

2 - Front right brake caliper

3 - Left rear brake caliper

4 - Right rear brake caliper

 

[hangman]

Bleeding sequence:

1 - Bleed left front and right front brake caliper together simultaneously.

2 - Bleed left rear and right rear brake caliper together simultaneously.

- With bleeder bottle hoses attached, leave bleeder valves open long enough that brake fluid exits without bubbles.

Then hydraulic unit must be bled once more via function "Basic setting" using Vehicle diagnostic tester.

Initiate basic setting (to bleed brake system):

Honestly, if you are just exchanging the fluid, it really won't matter so long as you don't let any circuit get too low. The above assumes you have a pressure bleeder.

Doing it with a helper:

Bleeding sequence:

1- Front left brake caliper

2 - Front right brake caliper

3 - Left rear brake caliper

4 - Right rear brake caliper

Yes, I have a Motive brake pressure bleed tank. I’m not sure if I have one bottle or two bottles for bleeding the calipers. I have to look in the garage later.

Thanks for the information!

I also have the Ross tech vcds cable. I’m not sure what the hydraulic unit is? Do I keep the pressurize system active during that part? Or is it just done through the Ross tech vcds cable?

 

[Nuje]

You shouldn't need to do the VCDS stuff if just flushing the system, though. Only need to do that if replacing a component within the hydraulic system (master cylinder, ABS pump....maybe a caliper, but probably don't need to with that if you're able to prevent air from getting in and traveling back toward the pump).

 

[Nuje]

I’m not sure what the hydraulic unit is?

My understanding is "hydraulic unit" = ABS pump.
If that gets opened to air (or otherwise gets air in it), you need 2bar (29psi) to properly bleed it.
(From the previous page of my screen grab above):
There Must Be a Positive Pressure of 2 Bar (29 psi) to Bleed the Hydraulic Unit.

 

[hangman]

I haven’t changed any calipers or brake lines. So I guess it’s just a normal brake fluid exchange/bleed?

 

[hangman]

Bleeding sequence:

1 - Bleed left front and right front brake caliper together simultaneously.

2 - Bleed left rear and right rear brake caliper together simultaneously.

- With bleeder bottle hoses attached, leave bleeder valves open long enough that brake fluid exits without bubbles.

Then hydraulic unit must be bled once more via function "Basic setting" using Vehicle diagnostic tester.

Initiate basic setting (to bleed brake system):

Honestly, if you are just exchanging the fluid, it really won't matter so long as you don't let any circuit get too low. The above assumes you have a pressure bleeder.

Doing it with a helper:

Bleeding sequence:

1- Front left brake caliper

2 - Front right brake caliper

3 - Left rear brake caliper

4 - Right rear brake caliper

I have to order another brake bleed catch bottle.
Once I have the pressurized tank with a new brake fluid, and I crack open both bleeder valves in the front, is it easier for one person to do this? Because that means I have to crack open both valves and shut them one at a time when the fluid comes through clear. I’ve never done it this way before.

 

[hangman]

By the way, I found this on the ground near the driver side rear. I’m assuming it came off the old brakes at some point. Can anyone tell me what this is?

IMG_7118.jpeg

• hangman
• Oct 31, 2023

This?

72047817041__EA836D14-40F4-4550-A31A-52213952EE1C.jpeg

• hangman
• Oct 31, 2023

What is this?

 

[5SP TDI]

That is a 1/4 oz. wheel weight.

 

[Nuje]

I have to order another brake bleed catch bottle.
Once I have the pressurized tank with a new brake fluid, and I crack open both bleeder valves in the front, is it easier for one person to do this? Because that means I have to crack open both valves and shut them one at a time when the fluid comes through clear. I’ve never done it this way before.

I've never seen anything suggesting to do the fronts together, then the rears together. The directions I've alway seen were the order I showed above, and just went around the car sequentially from nearest to furthest.

 

[hangman]

That is a 1/4 oz. wheel weight.

For use when balancing the wheels?

 

[Nuje]

Exactly.

 

[oilhammer]

I just cut 'n pasted the procedures from Alldata, FWIW.

If you are changing the fluid just for PM, and you do NOT mess with the ABS pump, then the fluid that is inside the ABS pump, will remain inside the ABS pump (which sort of means you are not really flushing the entire system). By doing the Output Tests, you are at least pushing fluid through it and "exercising" all of its valves... which in some cases depending on where you live and how you drive may be the only time the ABS pump and valves actually does get that. I rarely ever, even in winter, have my cars' ABS pumps come into action.