How to Refresh Brake Fluid by Yourself

11 Jun 2019

by Max G

How to Refresh Brake Fluid with a DIY tool!

We all like to have some decent brakes on our bikes because people tend to forget we are using the road as well...
Therefore we come up with a super simple tool which will make your brake fluid refreshing days a breeze.
The first thing you need is a big appetite for pickles (or any other kind of food that comes in a jar... like uhm whiskey?

The next thing you need is hoses. It is advised to take a transparent one so you can see the fluid inside). Make sure it is about 5mm (for a tight fit with the valve's nipple that follows underneath)

The last thing you need is a bicycle inner tube valve. If you cannot buy it without the inner tube, you could use the residual tube for a slingshot or so. (Nope, not making a How-To for this)

You start by drilling a small hole in the lid of the jar, so the fuel hose can just squeeze through it. (The tighter the fit, the better)

When this is done, you screw the bicycle inner tube valve into the fuel hose.
After this, you stick the hose with the valve side into the jar (through the lid).
The jar will be the container for old, stinky brake fluid.
(So, the RED Arrow is the NO GO zone for air, and the valve will help to make sure this will not happen).

Usually, when you are pumping air into an inner tube, the air will only get in. This "one-way-only" is precisely what you want when you are bleeding your brakes.

Fluid out, air NOT in.

The other side of the fuel hose (the non-valve side) should be slid over the nipple of the calliper.
Make sure you unscrew the nipple first, so the fluid can bleed from it. About a 180 to 270 degrees twist should be enough.

NOTE: If you have 2 callipers, you need 2 of these set-ups. This works on the rear brake as well.... obviously.

With every pump on your brake lever, the fluid will bleed into the jar, but will not suck air back into the calliper/ brake line, when you release it!

That simple! Make sure you keep filling up the brake fluid in the reservoir while pumping.
It is also good to shake/tap the bike and brake line(s) a bit to get the remaining air out.
Lesser air + fresher fluid = better brakes.

You should also read your manual to find out what type (dot) of brake fluid you need.

We hope this helped you to understand how to refresh brake fluid with your own DIY tool.
Enjoy braking!!