Boxerworks.com

How often do you flush your brake fluids?

Every 2 years but to honest more out of concern for corrosion protection than the lowered boiling point of the fluid. I doubt my brakes get anywhere near hot enough in my normal riding for it to be a concern.

One thing I learnt recently that makes brake fluid change an absolute breeze and totally fool proof is gravity bleeding. Just open up the bleed nipple and let the fluid flow through a short tube. Gravity bleeding works well on a bike because of the relatively high head of fluid and short system length offering low resistance. As long as the master cylinder is kept topped up there is zero chance of introducing air.

Minor correction.... DOT3, DOT4 and DOT5.1 brake fluids are "Hygroscopic"...

barryh wrote: ↑Tue Dec 26, 2017 9:44 am

One thing I learnt recently that makes brake fluid change an absolute breeze and totally fool proof is gravity bleeding. Just open up the bleed nipple and let the fluid flow through a short tube. Gravity bleeding works well on a bike because of the relatively high head of fluid and short system length offering low resistance. As long as the master cylinder is kept topped up there is zero chance of introducing air.

Interesting. So you just let the fluid drip out, and refill before the reservoir empties? Do you repeat more than once to get a flush? I can see where this might be less wear on the master seals.

I've hear so many having problems with bleeding brakes. I've rarely had an issue with it.

I refill 2 or 3 times. Gravity bleeding is no different in principle to pressure bleeding just the pressure is lower at approx. 1 psi. The advent of DOT 4 LV makes it an easier proposition due to the lower cold temperature viscosity. Most cars with ABS now specify this type of fluid so I first did a gravity bleed on my car. The fluid flows much better on a bike though whether Dot 4 LV or ordinary DOT 4 is used.