Brake Fluid Change In Lexus

[Wen36]

My Toyota maintenance manuals for Camry and Avalon do not require brake fluid changes even up to 120,000 miles. Does anyone know why Lexus cars, for example, ES330, require brake fluid change for every 30,000 miles?

[mzhuk]

My Toyota maintenance manuals for Camry and Avalon do not require brake fluid changes even up to 120,000 miles. Does anyone know why Lexus cars, for example, ES330, require brake fluid change for every 30,000 miles?

It is because brake fluid, at least dot 3 or 4, is hydrophilic meaning the fluid will absorb water (moisture) from the air and no brake system is completely closed meaning this will occur overtime. As this occures the boiling point of the fluid and its incompressible characteristics decline meaning stopping performance and power suffers for you. If you take a look at the manufactures website of whatever brake fluid you are going to be using it will normally say it should be changed every few years (normally 2, but some recommend 1).

Anyways once you change the fluid you will more likely have better response of the brakes and more pedal firmness assuming who ever does it does a complete flush of all the old fluid and bleeds the system.

[PrinceAli132]

It is because brake fluid, at least dot 3 or 4, is hydrophilic meaning the fluid will absorb water (moisture) from the air and no brake system is completely closed meaning this will occur overtime.

Not to nitpick but brake fluid is hygroscopic.

http://www.google.com/search?hl=en&q=d...mp;aqi=l1g7g-m1

As this occures the boiling point of the fluid and its incompressible characteristics decline meaning stopping performance and power suffers for you.

To add to this, manufactures of brake fluid provide us with two temperatures for their boiling points. One is for its dry boiling point, dry meaning with no water/moisture mixed in. The second temperature provided is for its wet boiling temperature, for which the fluid has absorb more water. From what I have heard better brake fluid (higher temp ratings) tend to absorb more water when compared to "normal" fluid.

Since I tend to over do maintenance, I usually just bleed the brakes around every 6 months and will probably flush i after the second or third bleed.

If you track your car or go through some absurd heavy braking then periodic bleeding and flushing is recommended.

Ali