Silicon brake fluid

When filling a system with DOT5

Bodyperson said

We had to flush the DOT 5 from a Limo project. Too much distance vs. the lack of compression left it with an endless soft pedal.
Smaller systems are not effected as much as larger systems.

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The soft pedal is caused by tiny bubbles in the fluid. DOT 5 must be never be shaken while in the bottle, and must be poured slowly into the master cyl. Using a gravity bleed or suction bleed seems to work better than having someone push the pedal to bleed. I agree, bubbles introduce compression in the fluid and could be a problem in a large volume system. I think this is why it is not to be used in an ABS system.