changing brake fluid

[Bofire]

someone told me why we need to do this but I forget, Why???
Carl

[toothfangclaw]

Brake fluid gathers moisture and moisture lowers the boiling point of brake fluid and can cause a soft pedal and loss of braking power.

[coachcw]

if it's dark swap it out

[Zardoz]

Brake fluid gathers moisture and moisture lowers the boiling point of brake fluid and can cause a soft pedal and loss of braking power.

 

[Alchase]

Can break fluid be change a little at a time from the reservoir, suck some out, refill, cycle it, repeat, without having to bleed the whole system?

[JLS]

Can break fluid be change a little at a time from the reservoir, suck some out, refill, cycle it, repeat, without having to bleed the whole system?

No.  Replace the fluid in the reservoir, then have someone help you bleed.  Start at rear driver, rear passenger, front passenger, front driver side.

[Grit dog]

Can break fluid be change a little at a time from the reservoir, suck some out, refill, cycle it, repeat, without having to bleed the whole system?

The best way is to bleed new fluid through, and if it's really old, that's the only way to really get er done.
I believe eventually it all mixes though, so at around 5 years old, I start replacing what's in the master cylinder periodically. After doing that 4-5x over the course of a few months theoretically I get most of the old fluid.
Lazy mans brake fluid change!

[MP123]

Can break fluid be change a little at a time from the reservoir, suck some out, refill, cycle it, repeat, without having to bleed the whole system?

The fluid down in the brake lines near the calipers isn't gonna work it's way back up to the master cylinder anytime soon.  Changing it all at once is the way to go.

It's really a pretty easy job, hardest part is getting the wheels off.  The pump up pressure tanks that screw onto the master cylinder make it an easy one man job. 

Like this: https://www.amazon.com/Motive-Products-101-System-Bleeder/dp/B00CJ5DWKO

[Chad Osterholtz]

Actually... The hardest part is getting the wife to help pump up the brakes!!!

[Knocker of rocks]

The pump up pressure tanks that screw onto the master cylinder make it an easy one man job. 

Yea, the pressure "pusher" types are a lot nicer than the vacuum "sucker" types.

[Bofire]

thanks

[Alchase]

Actually... The hardest part is getting the wife to help pump up the brakes!!!

LOL ya that