Changing brake fluid

[john2443]

From a thread on another (non petrol head) forum, someone said that you will only find out that you should have changed the brake fluid when you press the pedal and nothing happens - note CHANGED, not checked or topped up.

Clearly as a general safety thing you should change the fluid every few years (do we all do that? ) because it gradually takes on water which boils at a lower temp than brake fluid and potentially vapourises giving spongy brakes but, has anyone actually had a problem with brakes failing due to old fluid on a road car?

(I say road car because old fluid in a track car with repeated heavy braking is a different kettle of fish.)

[steveo3002]

they wont just fail overnight due to older fluid , makes good sense to change it when you can , i mostly notice the pedal feels a bit better

[LuS1fer]

Just changed mine. It'sa lways odd how people spend money on expensive pads and discs and leave the old fluid in.

[HustleRussell]

My Caterham gets fresh fluid at least every season. My road cars get fluid whenever is convenient but typically whenever I work on the braking system.
The fluid is a hydraulic oil and a lubricant, and when it absorbs water it tends to accumilate in the calipers and cause corrosion to the pistons (sticking calipers), and also accelerates the degradation of seals in master/slave sylinders. Obviously water also boils at a much lower temperature, and it is possible to get the brakes of a road car hot enough to boil it on the road.

[wolves_wanderer]

Not the brakes but my clutch started getting hard to disengage in heavy traffic on a hot day, new brake fluid has sorted it.