general brake question

[yARIC008]

I have a general brake question. When you have a brake system that is functioning the way it is supposed to, everything is sealed and good... when you run your engine and your brake lines heat up to 150+ degrees in the engine compartment and the brake fluid expands, even slightly, where does this expand to? Seems to me it would need to push backward past the master cylinder while the brake pedal is not pushed otherwise it would begin to engage the brakes. Also, when you are braking and your brakes heat up and expand the fluid aswell, where does that expansion go?

 

[TronDD]

How much expansion is there of brake fluid at 150* or so? Is it even significant?

I'd say, no pedal, expansion goes into the reservoir. While braking, it goes into the cylinders.

Tim.

 

[TWeatherford]

When you're not pressing the pedal, fluid can travel freely between the brake lines and master cylinder reservoir. The reservoir has a maximum as well as minimum fill line, to give room I'd imagine for any thermal expansion.