Brake fluid flush and colors

[JFENG]

Brake fluid simply pulses back and forth in the M/C, lines and calipers

Well, there’s bulk flow, eddy diffusion, and molecular diffusion.
There is no unidirectional bulk flow. But there is reciprocating bulk flow with induced eddy currents and also certainly diffusion.

So I agree with DQ that over time moisture that enters via the reservoir cap and piston seals also have nds up throughout the system. But I also agree that pushing the pistons home and refreshing the reservoir before bleeding the lines makes the job much quicker.

IIRC, isn’t there a new type of reservoir that contains an expandable bellows, eliminating a direct path to the atmosphere yet allowing brake fluid levels to fluctuate?

 

[JFENG]

fluid will stop falling in the very moment the rising fluid touches the mouth of the bottle

This principle is used in a number of pet water supply systems.

 

[Cornishman]

Thanks guys, I love this type of physics.
De Q, how do you take away then inverted with fluid in it without spilling any? Or. Do you need to keep going until it is used? Perhaps that is what all the towels were for

 

[deQuincey]

Thanks guys, I love this type of physics.
De Q, how do you take away then inverted with fluid in it without spilling any? Or. Do you need to keep going until it is used? Perhaps that is what all the towels were for

the towel is a precautionary measure
to remove the bottle just tilt it carefully and slowly, the mouth of the bottle is small, so it goes slowly out and you can catch it up