What is the correct procedure to bleed a D2's brakes?

[dmdigital]

I need to do this. From what I understand it is recommended that every 6 years (max) all brake fluid is replaced. Now apart from the standard brake calipar bleed (as detailed in RAVE - below) I understand I also need to do a power bleed and a modulator bleed.

If this is the case can anyone tell me what the correct procedure is for this (apart from click the button on Rovacom)?

Do I need to have the lines at the wheels open in the same order as a manual bleed? Should they all be closed?

Do I repeat a manual blead after the power bleed?
:confused:

From another site this is the procedure I have seen:
1. Bleed at all calipers again using the manual method as per RAVE.
2. With all caliper nipples closed perform an "ABS Power Bleed" followed by an "ABS Modulator Bleed".
3. Bleed at all calipers again using the manual method.

From RAVE this is the standard manual caliper bleed procedure:

70.25.02

Brake system bleeding
____________
Bleeding of the brake system can be carried out using the procedures given on TestBook, or by following the manual procedure given below.

WARNING: If the ABS modulator has been replaced, the brake system must be bled using the procedure on TestBook, to ensure that all air is expelled from the new modulator.

WARNING: Do not allow brake fluid to come into contact with eyes or skin.

Bleed
NOTE: This procedure covers bleeding the complete system, but where only the primary or secondary circuit have been disturbed in isolation, it should only be necessary to bleed that circuit. Partial bleeding of the hydraulic system is only permissible if a brake pipe or hose has been disconnected with only minor loss of fluid.

1. Do not allow fluid level in master cylinder to fall below ’MIN’ mark during bleeding.
2. Do not fill reservoir above ’MAX’ level.
3. Raise front and rear of vehicle.

WARNING: Do not work on or under a vehicle supported only by a jack. Always support the vehicle on safety stands.

4. Check all pipe and hose connections are tight and there are no signs of leakage.
5. Top-up fluid level in brake reservoir to ’MAX’ mark.

WARNING: Do not allow dirt or foreign liquids to enter the reservoir. Use only new DOT 4 brake fluid from airtight containers. Do not mix brands of brake fluid as they may not be compatible.

6. Attach bleed tube to the bleed screw on front brake caliper on the passenger side, submerge free end in a clear container containing brake fluid.
7. Apply pressure to brake pedal several times, then apply steady pressure.
8. Loosen bleed screw to release brake fluid and air. Allow pedal to return unassisted.
9. Depress brake pedal steadily through its full stroke and allow to return unassisted. Repeat procedure until a flow of clean air-free fluid is purged into container then, whilst holding pedal at end of downward stroke, tighten brake
caliper bleed screw to 10 Nm (7 lbf.ft).

CAUTION: Ensure the fluid in the reservoir is maintained between the minimum and maximum levels throughout the bleed procedure using new brake fluid.

10. Top-up brake fluid level to ’MAX’ mark.


If someone can confirm the power bleed and modulator bleed procedures, hopefully this can form a good technical how to on the forum.

[Blknight.aus]

if youve gotten air in the system you have no choice but to do the testbook bleed.

But if you're just doing a fluid change so long as you dont let the master cylinder suck air you can change it over the old fashioned way with a vac bleeder, pressure bleeder or the foot on the pedal pump it thtough method...

But in order to get fresh fluid into the ABS/TC pump You need to to its specific bleed.

The upshot of this is that you'll have good fluid down where it really counts but who knows what in the abs pump.

When I get my xmas pressie up and running I'll happily contribute to this with all the detail you could desire.

[dmdigital]

That would be great Dave.

I now understand the need for the pressure bleed as the manual caliper bleed obviously doesn't refresh everything completely in the ABS block.

[sniegy]

Hi dmTD5,
Hope things are well in Gove,;)

The recommended time is every 2 yrs or 40k km's the brake fluid be flushed from the Brake system.
Part of the 40k service is a full brake bleed anyaway.
As Blknight.aus has said & obviously speaking from a wealth of experience, bleeding the system will help the ABS system a lot & get rid of the crud that may exist in the valves which may cause problems.:D

[dmdigital]

Hi Pete,

Things are pretty hot and humid up here, it's that time of the year though.

Am I correct with the process of using the power bleed with the lines all closed?

[sniegy]

Hi dmtd5,
If u follow the procedure with T4, not sure with Rovacom etc, but what it does is bleed the valves, so opening of the bleed nuts at each like you would do in a amnual led is required, basically when is says yes, you hit the start button & open whichever wheel u are doing for a pre determined time, & after the valves have cycled it will stop & move to the next wheel.
BUT be careful as it uses more fluid when this is done & you DONT want to runout of fluid...Otherwise it is a complete restart from scratch. I did this on my first ever power bleed not realising how much fluid is used...then had to start the complete brake bleed over again, which includes a manual bleed then a power bleed.
Hope this helps.
Cheers

[dmdigital]

Thanks again Pete