Anyone Using DOT5 Silicone brake fluid?

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08-17-2019, 03:26 AM

#16

dr bob

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Quote:

Originally Posted by Mrmerlin

FWIW a lot of bleeding issues in the S 4 happen because air gets into the ABS unit
If this unit is not bled after the MC is done then you will usually trap air in the unit
I have had no issues with bleeding if I crack all of the B nuts on the ABS unit and push fluid out till no more bubbles show at the B nuts

Hi Stan --

I wish my results were that good. I just couldn't seem to get the air bubbles out of the ABS unit without the vacuum bleed technique. I tried manual bleeding with a person on the pedal, and power bleeding with a Motiv-like pressure bleeder, and just couldn't seem to get the pedal up and firm where it needed to be.

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08-17-2019, 08:13 AM

#17

Mrmerlin

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To expand on the bleeding fist step is gravity bleed start at the MC B nuts then to the tip
bleeder
then move to the ABS unit
fist open the inlet B nuts
then the outlets
What your looking for it just fluid to drip out as you can easily see bubbles in the fluid
then once this is done go back and have your helper use the pedal to push fluid and do each B nut again
Once past the ABS unit
go to bleed the wheels

Note on an original system I suggest to replace the proportioning valve prior to beginning the bleeding sequence most of them are filled with corrosion
Wheel bleed sequence is
LF RF LR RR