<>

Well, we are back to your understanding of physics again, are we ????
Fliuds DO NOT COMPRESS ..that is why they use them.....if they compressed , you would have ANY brakes !!!!!!!

I will only advise those here interested in changing their brake fluid of a few basics .

The main reason for fluid change is that brake fluids have a problem that inherently effects the wear and saftey to your brake system. This property
is that the fluid is 'Hygroscopic' . by definition, it absorbs MOISTURE...
..and moisture is the enemy of the internals of the brake system, along with the fact that it will boil at a lower temp than brake fluid not contaminated w/moisture.
So, manufactures recommend a simple change of fluid every couple of years
to keep the fluid safe, fresh, clean, and moisture free.
That's all, just like any fluid change..[ Some of this confusion can be attributed to US manufactures , as they never stressed this until of late, whereas the Euro guys always did ]

Now , lets understand the fluid res. tank of this post... This is a fluid tank that holds extra fluid . As the brake pads wear down , extra fluid to the brake system is needed to keep the system full . The res. fluid is then used to make up for the increased capacity of the extended caliper piston cavities. The res is not a working fluid as the fluid in the system is, it is just a res/tank of fluid to be used when the systems capacity increases due to pad wear.
So, just like any other fluid change, you want to change all the fluid in the brake system... not just the res tank...
When you change the anti-freeze coolant in the engine , you don't go change the A/F in the holding tank a few times .. you drain the block and radiator and add new coolant to the entire cooling system...... pretty close analogy.

Lastly, the brake lines go to each wheels braking unit and , because the fluid is non-compressable, the action of your foot on the pedal is transferred to a brake pad. ..and that is the end of the line..this fluid get very hot and the working of the calipers wear and add to the fluid contamination at these dead ends. That fluid never gets to make a trip back up to the res or anywhere else . It just stays there in the caliper/lines until you decide to change it by opening the bleeder and chase it out with NEW fluid that you put in the res. [ once you do one and see the crap come out at each bleeder , you will realize the importance of full fluid changes]
The turkey baster can be used to get the old fluid out of the res so that you can refill it with the new fluid you will use to push the old out of the lines with the bleeders open. but without open bleeders to vacate the old fluid, you are doing nothing but changing the fluid in the res ..the old contaminated fluid that the manufacturer wants to get rid of is still there and you have accomplished nothing more than refreshing your res tank...You have NOT CHANGED your braking systems working fluid.

I will leave it there as it is a simple concept to grasp.